Implementing IPv6 Multicast
• Information About Implementing IPv6 Multicast Routing, on page 1
• How to Implement IPv6 Multicast, on page 9
• Additional References, on page 31
• Feature History for IPv6 Multicast, on page 31
Information About Implementing IPv6 Multicast Routing
This chapter describes how to implement IPv6 multicast routing on the switch.
Traditional IP communication allows a host to send packets to a single host (unicast transmission) or to all
hosts (broadcast transmission). IPv6 multicast provides a third scheme, allowing a host to send a single data
stream to a subset of all hosts (group transmission) simultaneously.
IPv6 Multicast Overview
An IPv6 multicast group is an arbitrary group of receivers that want to receive a particular data stream. This
group has no physical or geographical boundaries--receivers can be located anywhere on the Internet or in
any private network. Receivers that are interested in receiving data flowing to a particular group must join
the group by signaling their local switch. This signaling is achieved with the MLD protocol.
Switches use the MLD protocol to learn whether members of a group are present on their directly attached
subnets. Hosts join multicast groups by sending MLD report messages. The network then delivers data to a
potentially unlimited number of receivers, using only one copy of the multicast data on each subnet. IPv6
hosts that wish to receive the traffic are known as group members.
Packets delivered to group members are identified by a single multicast group address. Multicast packets are
delivered to a group using best-effort reliability, just like IPv6 unicast packets.
The multicast environment consists of senders and receivers. Any host, regardless of whether it is a member
of a group, can send to a group. However, only members of a group can listen to and receive the message.
A multicast address is chosen for the receivers in a multicast group. Senders use that address as the destination
address of a datagram to reach all members of the group.
Implementing IPv6 Multicast
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As per RFC 4291, the FF0x::/12 (where the T flag is set to 0 in IPv6 destination address) is for permanently
assigned (“well-known”) IPv6 multicast address range.
In Cisco Catalyst 9300 Series Switches, the default behavior for packets with this address range is to flood
in the ingress VLAN.
Note
Membership in a multicast group is dynamic; hosts can join and leave at any time. There is no restriction on
the location or number of members in a multicast group. A host can be a member of more than one multicast
group at a time.
How active a multicast group is, its duration, and its membership can vary from group to group and from time
to time. A group that has members may have no activity.
IPv6 Multicast Routing Implementation
The Cisco IOS software supports the following protocols to implement IPv6 multicast routing:
• MLD is used by IPv6 switches to discover multicast listeners (nodes that want to receive multicast packets
destined for specific multicast addresses) on directly attached links. There are two versions of MLD:
MLD version 1 is based on version 2 of the Internet Group Management Protocol (IGMP) for IPv4, and
MLD version 2 is based on version 3 of the IGMP for IPv4. IPv6 multicast for Cisco IOS software uses
both MLD version 2 and MLD version 1. MLD version 2 is fully backward-compatible with MLD version
1 (described in RFC 2710). Hosts that support only MLD version 1 will interoperate with a switch running
MLD version 2. Mixed LANs with both MLD version 1 and MLD version 2 hosts are likewise supported.
• PIM-SM is used between switches so that they can track which multicast packets to forward to each
other and to their directly connected LANs.
• PIM in Source Specific Multicast (PIM-SSM) is similar to PIM-SM with the additional ability to report
interest in receiving packets from specific source addresses (or from all but the specific source addresses)
to an IP multicast address.
IPv6 Multicast Listener Discovery Protocol
To start implementing multicasting in the campus network, users must first define who receives the multicast.
The MLD protocol is used by IPv6 switches to discover the presence of multicast listeners (for example, nodes
that want to receive multicast packets) on their directly attached links, and to discover specifically which
multicast addresses are of interest to those neighboring nodes. It is used for discovering local group and
source-specific group membership.
The MLD protocol provides a means to automatically control and limit the flow of multicast traffic throughout
your network with the use of special multicast queriers and hosts.
Multicast Queriers and Hosts
A multicast querier is a network device, such as a switch, that sends query messages to discover which network
devices are members of a given multicast group.
A multicast host is a receiver, including switches, that send report messages to inform the querier of a host
membership.
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IPv6 Multicast Routing Implementation
A set of queriers and hosts that receive multicast data streams from the same source is called a multicast group.
Queriers and hosts use MLD reports to join and leave multicast groups and to begin receiving group traffic.
MLD uses the Internet Control Message Protocol (ICMP) to carry its messages. All MLD messages are
link-local with a hop limit of 1, and they all have the switch alert option set. The switch alert option implies
an implementation of the hop-by-hop option header.
MLD Access Group
The MLD access group provides receiver access control in Cisco IOS IPv6 multicast switches. This feature
limits the list of groups a receiver can join, and it allows or denies sources used to join SSM channels.
Explicit Tracking of Receivers
The explicit tracking feature allows a switch to track the behavior of the hosts within its IPv6 network. This
feature also enables the fast leave mechanism to be used with MLD version 2 host reports.
Protocol Independent Multicast
Protocol Independent Multicast (PIM) is used between switches so that they can track which multicast packets
to forward to each other and to their directly connected LANs. PIM works independently of the unicast routing
protocol to perform send or receive multicast route updates like other protocols. Regardless of which unicast
routing protocols are being used in the LAN to populate the unicast routing table, Cisco IOS PIM uses the
existing unicast table content to perform the Reverse Path Forwarding (RPF) check instead of building and
maintaining its own separate routing table.
You can configure IPv6 multicast to use either PIM-SM or PIM-SSM operation, or you can use both PIM-SM
and PIM-SSM together in your network.
PIM-Sparse Mode
IPv6 multicast provides support for intradomain multicast routing using PIM-SM. PIM-SM uses unicast
routing to provide reverse-path information for multicast tree building, but it is not dependent on any particular
unicast routing protocol.
PIM-SM is used in a multicast network when relatively few switches are involved in each multicast and these
switches do not forward multicast packets for a group, unless there is an explicit request for the traffic. PIM-SM
distributes information about active sources by forwarding data packets on the shared tree. PIM-SM initially
uses shared trees, which requires the use of an RP.
Requests are accomplished via PIM joins, which are sent hop by hop toward the root node of the tree. The
root node of a tree in PIM-SM is the RP in the case of a shared tree or the first-hop switch that is directly
connected to the multicast source in the case of a shortest path tree (SPT). The RP keeps track of multicast
groups and the hosts that send multicast packets are registered with the RP by that host's first-hop switch.
As a PIM join travels up the tree, switches along the path set up multicast forwarding state so that the requested
multicast traffic will be forwarded back down the tree. When multicast traffic is no longer needed, a switch
sends a PIM prune up the tree toward the root node to prune (or remove) the unnecessary traffic. As this PIM
prune travels hop by hop up the tree, each switch updates its forwarding state appropriately. Ultimately, the
forwarding state associated with a multicast group or source is removed.
A multicast data sender sends data destined for a multicast group. The designated switch (DR) of the sender
takes those data packets, unicast-encapsulates them, and sends them directly to the RP. The RP receives these
encapsulated data packets, de-encapsulates them, and forwards them onto the shared tree. The packets then
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Implementing IPv6 Multicast
MLD Access Group
follow the (*, G) multicast tree state in the switches on the RP tree, being replicated wherever the RP tree
branches, and eventually reaching all the receivers for that multicast group. The process of encapsulating data
packets to the RP is called registering, and the encapsulation packets are called PIM register packets.
IPv6 BSR: Configure RP Mapping
PIM switches in a domain must be able to map each multicast group to the correct RP address. The BSR
protocol for PIM-SM provides a dynamic, adaptive mechanism to distribute group-to-RP mapping information
rapidly throughout a domain. With the IPv6 BSR feature, if an RP becomes unreachable, it will be detected
and the mapping tables will be modified so that the unreachable RP is no longer used, and the new tables will
be rapidly distributed throughout the domain.
Every PIM-SM multicast group needs to be associated with the IP or IPv6 address of an RP. When a new
multicast sender starts sending, its local DR will encapsulate these data packets in a PIM register message
and send them to the RP for that multicast group. When a new multicast receiver joins, its local DR will send
a PIM join message to the RP for that multicast group. When any PIM switch sends a (*, G) join message,
the PIM switch needs to know which is the next switch toward the RP so that G (Group) can send a message
to that switch. Also, when a PIM switch is forwarding data packets using (*, G) state, the PIM switch needs
to know which is the correct incoming interface for packets destined for G, because it needs to reject any
packets that arrive on other interfaces.
A small set of switches from a domain are configured as candidate bootstrap switches (C-BSRs) and a single
BSR is selected for that domain. A set of switches within a domain are also configured as candidate RPs
(C-RPs); typically, these switches are the same switches that are configured as C-BSRs. Candidate RPs
periodically unicast candidate-RP-advertisement (C-RP-Adv) messages to the BSR of that domain, advertising
their willingness to be an RP. A C-RP-Adv message includes the address of the advertising C-RP, and an
optional list of group addresses and mask length fields, indicating the group prefixes for which the candidacy
is advertised. The BSR then includes a set of these C-RPs, along with their corresponding group prefixes, in
bootstrap messages (BSMs) it periodically originates. BSMs are distributed hop-by-hop throughout the domain.
Bidirectional BSR support allows bidirectional RPs to be advertised in C-RP messages and bidirectional
ranges in the BSM. All switches in a system must be able to use the bidirectional range in the BSM; otherwise,
the bidirectional RP feature will not function.
PIM-Source Specific Multicast
PIM-SSM is the routing protocol that supports the implementation of SSM and is derived from PIM-SM.
However, unlike PIM-SM where data from all multicast sources are sent when there is a PIM join, the SSM
feature forwards datagram traffic to receivers from only those multicast sources that the receivers have explicitly
joined, thus optimizing bandwidth utilization and denying unwanted Internet broadcast traffic. Further, instead
of the use of RP and shared trees, SSM uses information found on source addresses for a multicast group.
This information is provided by receivers through the source addresses relayed to the last-hop switches by
MLD membership reports, resulting in shortest-path trees directly to the sources.
In SSM, delivery of datagrams is based on (S, G) channels. Traffic for one (S, G) channel consists of datagrams
with an IPv6 unicast source address S and the multicast group address G as the IPv6 destination address.
Systems will receive this traffic by becoming members of the (S, G) channel. Signaling is not required, but
receivers must subscribe or unsubscribe to (S, G) channels to receive or not receive traffic from specific
sources.
MLD version 2 is required for SSM to operate. MLD allows the host to provide source information. Before
SSM can run with MLD, SSM must be supported in the Cisco IOS IPv6 switch, the host where the application
is running, and the application itself.
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IPv6 BSR: Configure RP Mapping
Routable Address Hello Option
When an IPv6 interior gateway protocol is used to build the unicast routing table, the procedure to detect the
upstream switch address assumes the address of a PIM neighbor is always same as the address of the next-hop
switch, as long as they refer to the same switch. However, it may not be the case when a switch has multiple
addresses on a link.
Two typical situations can lead to this situation for IPv6. The first situation can occur when the unicast routing
table is not built by an IPv6 interior gateway protocol such as multicast BGP. The second situation occurs
when the address of an RP shares a subnet prefix with downstream switches (note that the RP switch address
has to be domain-wide and therefore cannot be a link-local address).
The routable address hello option allows the PIM protocol to avoid such situations by adding a PIM hello
message option that includes all the addresses on the interface on which the PIM hello message is advertised.
When a PIM switch finds an upstream switch for some address, the result of RPF calculation is compared
with the addresses in this option, in addition to the PIM neighbor's address itself. Because this option includes
all the possible addresses of a PIM switch on that link, it always includes the RPF calculation result if it refers
to the PIM switch supporting this option.
Because of size restrictions on PIM messages and the requirement that a routable address hello option fits
within a single PIM hello message, a limit of 16 addresses can be configured on the interface.
PIM IPv6 Stub Routing
The PIM stub routing feature reduces resource usage by moving routed traffic closer to the end user.
In a network using PIM stub routing, the only allowable route for IPv6 traffic to the user is through a switch
that is configured with PIM stub routing. PIM passive interfaces are connected to Layer 2 access domains,
such as VLANs, or to interfaces that are connected to other Layer 2 devices. Only directly connected multicast
receivers and sources are allowed in the Layer 2 access domains. The PIM passive interfaces do not send or
process any received PIM control packets.
When using PIM stub routing, you should configure the distribution and remote routers to use IPv6 multicast
routing and configure only the switch as a PIM stub router. The switch does not route transit traffic between
distribution routers. You also need to configure a routed uplink port on the switch. The switch uplink port
cannot be used with SVIs.
You must also configure EIGRP stub routing when configuring PIM stub routing on the switch.
The redundant PIM stub router topology is not supported. The redundant topology exists when there is more
than one PIM router forwarding multicast traffic to a single access domain. PIM messages are blocked, and
the PIM assert and designated router election mechanisms are not supported on the PIM passive interfaces.
Only the non-redundant access router topology is supported by the PIM stub feature. By using a non-redundant
topology, the PIM passive interface assumes that it is the only interface and designated router on that access
domain.
In the figure shown below, Switch A routed uplink port 25 is connected to the router and PIM stub routing is
enabled on the VLAN 100 interfaces and on Host 3. This configuration allows the directly connected hosts
to receive traffic from multicast source.
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Implementing IPv6 Multicast
Routable Address Hello Option
Figure 1: PIM Stub Router Configuration
Rendezvous Point
IPv6 PIM provides embedded RP support. Embedded RP support allows the device to learn RP information
using the multicast group destination address instead of the statically configured RP. For devices that are the
RP, the device must be statically configured as the RP.
The device searches for embedded RP group addresses in MLD reports or PIM messages and data packets.
On finding such an address, the device learns the RP for the group from the address itself. It then uses this
learned RP for all protocol activity for the group. For devices that are the RP, the device is advertised as an
embedded RP must be configured as the RP.
To select a static RP over an embedded RP, the specific embedded RP group range or mask must be configured
in the access list of the static RP. When PIM is configured in sparse mode, you must also choose one or more
devices to operate as an RP. An RP is a single common root placed at a chosen point of a shared distribution
tree and is configured statically in each box.
PIM DRs forward data from directly connected multicast sources to the RP for distribution down the shared
tree. Data is forwarded to the RP in one of two ways:
• Data is encapsulated in register packets and unicast directly to the RP by the first-hop device operating
as the DR.
• If the RP has itself joined the source tree, it is multicast-forwarded per the RPF forwarding algorithm
described in the PIM-Sparse Mode section.
The RP address is used by first-hop devices to send PIM register messages on behalf of a host sending a packet
to the group. The RP address is also used by last-hop devices to send PIM join and prune messages to the RP
to inform it about group membership. You must configure the RP address on all devices (including the RP
device).
A PIM device can be an RP for more than one group. Only one RP address can be used at a time within a
PIM domain for a certain group. The conditions specified by the access list determine for which groups the
device is an RP.
IPv6 multicast supports the PIM accept register feature, which is the ability to perform PIM-SM register
message filtering at the RP. The user can match an access list or compare the AS path for the registered source
with the AS path specified in a route map.
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Implementing IPv6 Multicast
Rendezvous Point
Static Mroutes
IPv6 static mroutes behave much in the same way as IPv4 static mroutes used to influence the RPF check.
IPv6 static mroutes share the same database as IPv6 static routes and are implemented by extending static
route support for RPF checks. Static mroutes support equal-cost multipath mroutes, and they also support
unicast-only static routes.
MRIB
The Multicast Routing Information Base (MRIB) is a protocol-independent repository of multicast routing
entries instantiated by multicast routing protocols (routing clients). Its main function is to provide independence
between routing protocols and the Multicast Forwarding Information Base (MFIB). It also acts as a coordination
and communication point among its clients.
Routing clients use the services provided by the MRIB to instantiate routing entries and retrieve changes made
to routing entries by other clients. Besides routing clients, MRIB also has forwarding clients (MFIB instances)
and special clients such as MLD. MFIB retrieves its forwarding entries from MRIB and notifies the MRIB
of any events related to packet reception. These notifications can either be explicitly requested by routing
clients or spontaneously generated by the MFIB.
Another important function of the MRIB is to allow for the coordination of multiple routing clients in
establishing multicast connectivity within the same multicast session. MRIB also allows for the coordination
between MLD and routing protocols.
MFIB
The MFIB is a platform-independent and routing-protocol-independent library for IPv6 software. Its main
purpose is to provide a Cisco IOS platform with an interface with which to read the IPv6 multicast forwarding
table and notifications when the forwarding table changes. The information provided by the MFIB has clearly
defined forwarding semantics and is designed to make it easy for the platform to translate to its specific
hardware or software forwarding mechanisms.
When routing or topology changes occur in the network, the IPv6 routing table is updated, and those changes
are reflected in the MFIB. The MFIB maintains next-hop address information based on the information in the
IPv6 routing table. Because there is a one-to-one correlation between MFIB entries and routing table entries,
the MFIB contains all known routes and eliminates the need for route cache maintenance that is associated
with switching paths such as fast switching and optimum switching.
MFIB
Distributed MFIB has its significance only in a stacked environment where the active switch distributes the
MFIB information to the other member switches in the stack. In the following section the line cards are nothing
but the member switches in the stack.
Note
MFIB (MFIB) is used to switch multicast IPv6 packets on distributed platforms. MFIB may also contain
platform-specific information on replication across line cards. The basic MFIB routines that implement the
core of the forwarding logic are common to all forwarding environments.
MFIB implements the following functions:
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Static Mroutes
• Relays data-driven protocol events generated in the line cards to PIM.
• Provides an MFIB platform application program interface (API) to propagate MFIB changes to
platform-specific code responsible for programming the hardware acceleration engine. This API also
includes entry points to switch a packet in software (necessary if the packet is triggering a data-driven
event) and to upload traffic statistics to the software.
The combination of MFIB and MRIB subsystems also allows the switch to have a "customized" copy of the
MFIB database in each line card and to transport MFIB-related platform-specific information from the RP to
the line cards.
IPv6 Multicast Process Switching and Fast Switching
A unified MFIB is used to provide both fast switching and process switching support for PIM-SM and
PIM-SSM in IPv6 multicast. In process switching, the must examine, rewrite, and forward each packet. The
packet is first received and copied into the system memory. The switch then looks up the Layer 3 network
address in the routing table. The Layer 2 frame is then rewritten with the next-hop destination address and
sent to the outgoing interface. The also computes the cyclic redundancy check (CRC). This switching method
is the least scalable method for switching IPv6 packets.
IPv6 multicast fast switching allows switches to provide better packet forwarding performance than process
switching. Information conventionally stored in a route cache is stored in several data structures for IPv6
multicast switching. The data structures provide optimized lookup for efficient packet forwarding.
In IPv6 multicast forwarding, the first packet is fast-switched if the PIM protocol logic allows it. In IPv6
multicast fast switching, the MAC encapsulation header is precomputed. IPv6 multicast fast switching uses
the MFIB to make IPv6 destination prefix-based switching decisions. In addition to the MFIB, IPv6 multicast
fast switching uses adjacency tables to prepend Layer 2 addressing information. The adjacency table maintains
Layer 2 next-hop addresses for all MFIB entries.
The adjacency table is populated as adjacencies are discovered. Each time an adjacency entry is created (such
as through ARP), a link-layer header for that adjacent node is precomputed and stored in the adjacency table.
Once a route is determined, it points to a next hop and corresponding adjacency entry. It is subsequently used
for encapsulation during switching of packets.
A route might have several paths to a destination prefix, such as when a switch is configured for simultaneous
load balancing and redundancy. For each resolved path, a pointer is added for the adjacency corresponding
to the next-hop interface for that path. This mechanism is used for load balancing across several paths.
Multiprotocol BGP for the IPv6 Multicast Address Family
The multiprotocol BGP for the IPv6 multicast address family feature provides multicast BGP extensions for
IPv6 and supports the same features and functionality as IPv4 BGP. IPv6 enhancements to multicast BGP
include support for an IPv6 multicast address family and network layer reachability information(NLRI) and
next hop (the next switch in the path to the destination) attributes that use IPv6 addresses.
Multicast BGP is an enhanced BGP that allows the deployment of interdomain IPv6 multicast. Multiprotocol
BGP carries routing information for multiple network layer protocol address families; for example, IPv6
address family and for IPv6 multicast routes. The IPv6 multicast address family contains routes used for RPF
lookup by the IPv6 PIM protocol, and multicast BGP IPV6 provides for interdomain transport of the same.
Users must use multiprotocol BGP for IPv6 multicast when using IPv6 multicast with BGP because the unicast
BGP learned routes will not be used for IPv6 multicast.
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IPv6 Multicast Process Switching and Fast Switching
Multicast BGP functionality is provided through a separate address family context. A subsequent address
family identifier (SAFI) provides information about the type of the network layer reachability information
that is carried in the attribute. Multiprotocol BGP unicast uses SAFI 1 messages, and multiprotocol BGP
multicast uses SAFI 2 messages. SAFI 1 messages indicate that the routes are only usable for IP unicast, but
not IP multicast. Because of this functionality, BGP routes in the IPv6 unicast RIB must be ignored in the
IPv6 multicast RPF lookup.
A separate BGP routing table is maintained to configure incongruent policies and topologies (forexample,
IPv6 unicast and multicast) by using IPv6 multicast RPF lookup. Multicast RPF lookup is very similar to the
IP unicast route lookup.
No MRIB is associated with the IPv6 multicast BGP table. However, IPv6 multicast BGP operates on the
unicast IPv6 RIB when needed. Multicast BGP does not insert or update routes into the IPv6 unicast RIB.
How to Implement IPv6 Multicast
Enabling IPv6 Multicast Routing
To enable IPv6 multicast routing, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enter global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Enables multicast routing on all IPv6-enabled
interfaces and enables multicast forwarding for
ipv6 multicast-routing
Example:
Step 3
PIM and MLD on all enabled interfaces of the
switch.
Device(config)# ipv6 multicast-routing
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Example:
Step 4
Device(config)# copy running-config
startup-config
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Implementing IPv6 Multicast
How to Implement IPv6 Multicast
Customizing and Verifying the MLD Protocol
Customizing and Verifying MLD on an Interface
To customize and verify MLD on an interface, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Specifies an interface type and number, and
places the switch in interface configuration
mode.
interface type number
Example:
Device(config)# interface
GigabitEthernet 1/0/1
Step 3
Configures MLD reporting for a specified
group and source.
ipv6 mld join-group [group-address] [include
| exclude] {source-address | source-list [acl]}
Example:
Step 4
Device(config-if)# ipv6 mld join-group
FF04::10
Allows the user to perform IPv6 multicast
receiver access control.
ipv6 mld access-group access-list-name
Example:
Step 5
Device(config-if)# ipv6 access-list
acc-grp-1
Statically forwards traffic for the multicast
group onto a specified interface and cause the
ipv6 mld static-group [group-address]
[include | exclude] {source-address |
source-list [acl]}
Step 6
interface to behave as if a MLD joiner were
present on the interface.
Example:
Device(config-if)# ipv6 mld static-group
ff04::10 include 100::1
Configures the timeout value before the switch
takes over as the querier for the interface.
ipv6 mld query-max-response-time seconds
Example:
Step 7
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Implementing IPv6 Multicast
Customizing and Verifying the MLD Protocol
PurposeCommand or Action
Device(config-if)# ipv6 mld
query-timeout 130
Enter this command twice to exit interface
configuration mode and enter privileged EXEC
mode.
exit
Example:
Device(config-if)# exit
Step 8
Displays the multicast groups that are directly
connected to the switch and that were learned
through MLD.
show ipv6 mld groups [link-local] [
group-name | group-address] [interface-type
interface-number] [detail | explicit]
Example:
Step 9
Device# show ipv6 mld groups
GigabitEthernet 1/0/1
Displays the number of (*, G) and (S, G)
membership reports present in the MLD cache.
show ipv6 mld groups summary
Example:
Step 10
Device# show ipv6 mld groups summary
Displays multicast-related information about
an interface.
show ipv6 mld interface [type number]
Example:
Step 11
Device# show ipv6 mld interface
GigabitEthernet 1/0/1
Enables debugging on MLD protocol activity.debugipv6 mld [group-name | group-address
| interface-type]
Step 12
Example:
Device# debug ipv6 mld
Displays information related to the explicit
tracking of hosts.
debug ipv6 mld explicit [group-name |
group-address
Example:
Step 13
Device# debug ipv6 mld explicit
(Optional) Save your entries in the
configuration file.
copy running-config startup-config
Step 14
Implementing MLD Group Limits
Per-interface and global MLD limits operate independently of each other. Both per-interface and global MLD
limits can be configured on the same switch. The number of MLD limits, globally or per interface, is not
configured by default; the limits must be configured by the user. A membership report that exceeds either the
per-interface or the global state limit is ignored.
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Implementing IPv6 Multicast
Implementing MLD Group Limits
Implementing MLD Group Limits Globally
To implement MLD group limits globally, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Limits the number of MLD states globally.ipv6 mld [vrf vrf-name] state-limit number
Example:
Step 3
Device(config)# ipv6 mld state-limit 300
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 4
Implementing MLD Group Limits per Interface
To implement MLD group limits per interface, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Specifies an interface type and number, and
places the switch in interface configuration
mode.
interface type number
Example:
Device(config)# interface GigabitEthernet
Step 3
1/0/1
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Implementing MLD Group Limits Globally
PurposeCommand or Action
Limits the number of MLD states on a
per-interface basis.
ipv6 mld limit number [except]access-list
Example:
Step 4
Device(config-if)# ipv6 mld limit 100
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 5
Configuring Explicit Tracking of Receivers to Track Host Behavior
The explicit tracking feature allows a switch to track the behavior of the hosts within its IPv6 network and
enables the fast leave mechanism to be used with MLD version 2 host reports.
To configuring explicit tracking of receivers to track host behavior, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enter global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Specifies an interface type and number, and
places the switch in interface configuration
mode.
interface type number
Example:
Device(config)# interface GigabitEthernet
1/0/1
Step 3
Enables explicit tracking of hosts.ipv6 mld explicit-tracking access-list-name
Example:
Step 4
Device(config-if)# ipv6 mld
explicit-tracking list1
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 5
Resetting the MLD Traffic Counters
To reset the MLD traffic counters, perform this procedure:
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13
Implementing IPv6 Multicast
Configuring Explicit Tracking of Receivers to Track Host Behavior
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Resets all MLD traffic counters.clear ipv6 mld traffic
Example:
Step 3
Device# clear ipv6 mld traffic
Displays the MLD traffic counters.show ipv6 mld traffic
Example:
Step 4
Device# show ipv6 mld traffic
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 5
Clearing the MLD Interface Counters
To clearing the MLD interface counters, perform this procedure
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Clears the MLD interface counters.clear ipv6 mld counters interface-type
Example:
Step 3
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14
Implementing IPv6 Multicast
Clearing the MLD Interface Counters
PurposeCommand or Action
Device# clear ipv6 mld counters
Ethernet1/0
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 4
Configuring PIM
This section explains how to configure PIM.
Configuring PIM-SM and Displaying PIM-SM Information for a Group Range
To configuring PIM-SM and view PIM-SM information for a group range, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Configures the address of a PIM RP for a
particular group range.
ipv6 pim rp-address
ipv6-address[group-access-list]
Example:
Step 3
Device(config)# ipv6 pim rp-address
2001:DB8::01:800:200E:8C6C acc-grp-1
Exits global configuration mode, and returns
the switch to privileged EXEC mode.
exit
Example:
Step 4
Device(config)# exit
Displays information about interfaces
configured for PIM.
show ipv6 pim interface [state-on] [state-off]
[type-number]
Example:
Step 5
Device# show ipv6 pim interface
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15
Implementing IPv6 Multicast
Configuring PIM
PurposeCommand or Action
Displays an IPv6 multicast group mapping
table.
show ipv6 pim group-map [group-name |
group-address] | [group-range | group-mask]
[info-source {bsr | default | embedded-rp |
static}]
Step 6
Example:
Device# show ipv6 pim group-map
Displays the PIM neighbors discovered by the
Cisco IOS software.
show ipv6 pim neighbor [detail]
[interface-type interface-number | count]
Example:
Step 7
Device# show ipv6 pim neighbor
Displays information about IPv6 multicast
range lists.
show ipv6 pim range-list [config] [rp-address
| rp-name]
Example:
Step 8
Device# show ipv6 pim range-list
Displays information about the PIM register
encapsulation and de-encapsulation tunnels on
an interface.
show ipv6 pim tunnel [interface-type
interface-number]
Example:
Step 9
Device# show ipv6 pim tunnel
Enables debugging on PIM protocol activity.debugipv6 pim [group-name | group-address
| interface interface-type | bsr | group | mvpn
| neighbor]
Step 10
Example:
Device# debug ipv6 pim
(Optional) Save your entries in the
configuration file.
copy running-config startup-config
Step 11
Configuring PIM Options
To configure PIM options, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
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Implementing IPv6 Multicast
Configuring PIM Options
PurposeCommand or Action
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Configures when a PIM leaf switch joins the
SPT for the specified groups.
ipv6 pim spt-threshold infinity [group-list
access-list-name]
Example:
Step 3
Device(config)# ipv6 pim spt-threshold
infinity group-list acc-grp-1
Accepts or rejects registers at the RP.ipv6 pim accept-register {list access-list |
route-map map-name}
Step 4
Example:
Device(config)# ipv6 pim accept-register
route-map reg-filter
Specifies an interface type and number, and
places the switch in interface configuration
mode.
interface type number
Example:
Device(config)# interface
GigabitEthernet 1/0/1
Step 5
Configures the DR priority on a PIM switch.ipv6 pim dr-priority value
Example:
Step 6
Device(config-if)# ipv6 pim dr-priority
3
Configures the frequency of PIM hello
messages on an interface.
ipv6 pim hello-interval seconds
Example:
Step 7
Device(config-if)# ipv6 pim
hello-interval 45
Configures periodic join and prune
announcement intervals for a specified
interface.
ipv6 pim join-prune-interval seconds
Example:
Device(config-if)# ipv6 pim
join-prune-interval 75
Step 8
Enter this command twice to exit interface
configuration mode and enter privileged EXEC
mode.
exit
Example:
Device(config-if)# exit
Step 9
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Implementing IPv6 Multicast
Configuring PIM Options
PurposeCommand or Action
Displays the average join-prune aggregation
for the most recently aggregated packets for
each interface.
ipv6 pim join-prune statistic [interface-type]
Example:
Device(config-if)# show ipv6 pim
join-prune statistic
Step 10
(Optional) Save your entries in the
configuration file.
copy running-config startup-config
Step 11
Resetting the PIM Traffic Counters
If PIM malfunctions or in order to verify that the expected number of PIM packets are received and sent, the
user can clear PIM traffic counters. Once the traffic counters are cleared, the user can enter the show ipv6
pim traffic command to verify that PIM is functioning correctly and that PIM packets are being received and
sent correctly.
To resetting the PIM traffic counters, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Resets the PIM traffic counters.clear ipv6 pim traffic
Example:
Step 3
Device# clear ipv6 pim traffic
Displays the PIM traffic counters.show ipv6 pim traffic
Example:
Step 4
Device# show ipv6 pim traffic
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 5
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Implementing IPv6 Multicast
Resetting the PIM Traffic Counters
Clearing the PIM Topology Table to Reset the MRIB Connection
No configuration is necessary to use the MRIB. However, users may in certain situations want to clear the
PIM topology table in order to reset the MRIB connection and verify MRIB information.
To clear the PIM topology table to reset the MRIB connection, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Clears the PIM topology table.clear ipv6 pim topology [group-name |
group-address]
Step 3
Example:
Device# clear ipv6 pim topology FF04::10
Displays multicast-related information about
an interface.
show ipv6 mrib client [filter] [name
{client-name | client-name : client-id}]
Example:
Step 4
Device# show ipv6 mrib client
Displays the MRIB route information.show ipv6 mrib route {link-local | summary
| [sourceaddress-or-name | *]
[groupname-or-address[ prefix-length]]]
Step 5
Example:
Device# show ipv6 mrib route
Displays PIM topology table information for
a specific group or all groups.
show ipv6 pim topology
[groupname-or-address
[sourceaddress-or-name] | link-local |
route-count [detail]]
Step 6
Example:
Device# show ipv6 pim topology
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Implementing IPv6 Multicast
Clearing the PIM Topology Table to Reset the MRIB Connection
PurposeCommand or Action
Enables debugging on MRIB client
management activity.
debug ipv6 mrib client
Example:
Step 7
Device# debug ipv6 mrib client
Enables debugging on MRIB I/O events.debug ipv6 mrib io
Example:
Step 8
Device# debug ipv6 mrib io
Enables debugging on MRIB proxy activity
between the switch processor and line cards
on distributed switch platforms.
debug ipv6 mrib proxy
Example:
Device# debug ipv6 mrib proxy
Step 9
Displays information about MRIB routing
entry-related activity.
debug ipv6 mrib route [group-name |
group-address]
Example:
Step 10
Device# debug ipv6 mrib route
Enables debugging on MRIB table
management activity.
debug ipv6 mrib table
Example:
Step 11
Device# debug ipv6 mrib table
(Optional) Save your entries in the
configuration file.
copy running-config startup-config
Step 12
Configuring PIM IPv6 Stub Routing
The PIM Stub routing feature supports multicast routing between the distribution layer and the access layer.
It supports two types of PIM interfaces, uplink PIM interfaces, and PIM passive interfaces. A routed interface
configured with the PIM passive mode does not pass or forward PIM control traffic, it only passes and forwards
MLD traffic.
PIM IPv6 Stub Routing Configuration Guidelines
• Before configuring PIM stub routing, you must have IPv6 multicast routing configured on both the stub
router and the central router. You must also have PIM mode (sparse-mode) configured on the uplink
interface of the stub router.
• The PIM stub router does not route the transit traffic between the distribution routers. Unicast (EIGRP)
stub routing enforces this behavior. You must configure unicast stub routing to assist the PIM stub router
behavior. For more information, see the EIGRP Stub Routing section.
• Only directly connected multicast (MLD) receivers and sources are allowed in the Layer 2 access domains.
The PIM protocol is not supported in access domains.
• The redundant PIM stub router topology is not supported.
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Implementing IPv6 Multicast
Configuring PIM IPv6 Stub Routing
Default IPv6 PIM Routing Configuration
This table displays the default IPv6 PIM routing configuration for the .
Table 1: Default Multicast Routing Configuration
Default SettingFeature
Disabled on all interfaces.Multicast routing
Version 2.PIM version
No mode is defined.PIM mode
None configured.PIM stub routing
None configured.PIM RP address
Disabled.PIM domain border
None.PIM multicast boundary
Disabled.Candidate BSRs
Disabled.Candidate RPs
0 kb/s.Shortest-path tree threshold rate
30 seconds.PIM router query message interval
Enabling IPV6 PIM Stub Routing
To enable IPV6 PIM stub routing, perform this procedure:
Before you begin
PIM stub routing is disabled in IPv6 by default.
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
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Implementing IPv6 Multicast
Default IPv6 PIM Routing Configuration
PurposeCommand or Action
Enables IPv6 Multicast PIM routing on the
switch.
ipv6 multicast pim-passive-enable
Example:
Step 3
Device(config-if)# ipv6 multicast
pim-passive-enable
Specifies the interface on which you want to
enable PIM stub routing, and enters interface
configuration mode.
interface interface-id
Example:
Device(config)# interface gigabitethernet
Step 4
The specified interface must be one of the
following:
9/0/6
• A routed port—A physical port that has
been configured as a Layer 3 port by
entering the no switchport interface
configuration command. You will also
need to enable IP PIM sparse mode on the
interface, and join the interface as a
statically connected member to an MLD
static group.
• An SVI—A VLAN interface created by
using the interface vlan vlan-id global
configuration command. You will also
need to enable IP PIM sparse mode on the
VLAN, join the VLAN as a statically
connected member to an MLD static
group, and then enable MLD snooping on
the VLAN, the MLD static group, and
physical interface.
These interfaces must have IPv6 addresses
assigned to them.
Enables the PIM on the interface.ipv6 pim
Example:
Step 5
Device(config-if)# ipv6 pim
Configures the various PIM stub features on the
interface.
ipv6 pim {bsr} | {dr-priority | value} |
{hello-interval | seconds} |
{join-prune-interval | seconds} | {passive}
Step 6
Enter bsr to configure BSR on a PIM switch
Example:
Enter dr-priority to configure the DR priority
on a PIM switch.
Device(config-if)# ipv6 pim
bsr|dr-priority|hello-interval|join-prune-interval|passive
Enter hello-interval to configure the frequency
of PIM hello messages on an interface.
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Implementing IPv6 Multicast
Enabling IPV6 PIM Stub Routing
PurposeCommand or Action
Enter join-prune-interval to configure periodic
join and prune announcement intervals for a
specified interface.
Enter passive to configure the PIM in the
passive mode.
Returns to privileged EXEC mode.end
Example:
Step 7
Device(config-if)# end
Monitoring IPv6 PIM Stub Routing
Table 2: PIM Stub Configuration show Commands
PurposeCommand
Displays the PIM stub that is enabled on each interface.show ipv6 pim interface
Displays the interested clients that have joined the specific multicast
source group.
show ipv6 mld groups
Verifies that the multicast stream forwards from the source to the
interested clients.
show ipv6 mroute
Configuring a BSR
The tasks included here are described below.
Configuring a BSR and Verifying BSR Information
To configure and verify BSR Information, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
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Implementing IPv6 Multicast
Monitoring IPv6 PIM Stub Routing
PurposeCommand or Action
Configures a switch to be a candidate BSR.ipv6 pim bsr candidate bsr
ipv6-address[hash-mask-length] [priority
priority-value]
Step 3
Example:
Device(config)# ipv6 pim bsr candidate
bsr 2001:DB8:3000:3000::42 124 priority
10
Specifies an interface type and number, and
places the switch in interface configuration
mode.
interface type number
Example:
Device(config)# interface GigabitEthernet
1/0/1
Step 4
Specifies an interface type and number, and
places the switch in interface configuration
mode.
ipv6 pim bsr border
Example:
Device(config-if)# ipv6 pim bsr border
Step 5
Enter this command twice to exit interface
configuration mode and enter privileged EXEC
mode.
exit
Example:
Device(config-if)# exit
Step 6
Displays information related to PIM BSR
protocol processing.
show ipv6 pim bsr {election | rp-cache |
candidate-rp}
Example:
Step 7
Device(config-if)# show ipv6 pim bsr
election
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 8
Sending PIM RP Advertisements to the BSR
To sending PIM RP advertisements to the BSR, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
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24
Implementing IPv6 Multicast
Sending PIM RP Advertisements to the BSR
PurposeCommand or Action
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Sends PIM RP advertisements to the BSR.ipv6 pim bsr candidate rp ipv6-address
[group-list access-list-name] [priority
priority-value] [interval seconds]
Step 3
Example:
Device(config)# ipv6 pim bsr candidate
rp 2001:DB8:3000:3000::42 priority 0
Specifies an interface type and number, and
places the switch in interface configuration
mode.
interface type number
Example:
Device(config)# interface GigabitEthernet
1/0/1
Step 4
Configures a border for all BSMs of any scope
on a specified interface.
ipv6 pim bsr border
Example:
Step 5
Device(config-if)# ipv6 pim bsr border
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 6
Configuring BSR for Use Within Scoped Zones
To configure BSR for use within scoped zones, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Configures a switch to be a candidate BSR.ipv6 pim bsr candidate rp ipv6-address
[hash-mask-length] [priority priority-value]
Step 3
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25
Implementing IPv6 Multicast
Configuring BSR for Use Within Scoped Zones
PurposeCommand or Action
Example:
Device(config)# ipv6 pim bsr candidate
bsr 2001:DB8:1:1:4
Configures the candidate RP to send PIM RP
advertisements to the BSR.
ipv6 pim bsr candidate rp ipv6-address
[group-list access-list-name] [priority
priority-value] [interval seconds]
Step 4
Example:
Device(config)# ipv6 pim bsr candidate
rp 2001:DB8:1:1:1 group-list list scope
6
Specifies an interface type and number, and
places the switch in interface configuration
mode.
interface type number
Example:
Device(config-if)# interface
GigabitEthernet 1/0/1
Step 5
Configures a multicast boundary on the
interface for a specified scope.
ipv6 multicast boundary scope scope-value
Example:
Step 6
Device(config-if)# ipv6 multicast
boundary scope 6
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 7
Configuring BSR Switches to Announce Scope-to-RP Mappings
IPv6 BSR switches can be statically configured to announce scope-to-RP mappings directly instead of learning
them from candidate-RP messages. A user might want to configure a BSR switch to announce scope-to-RP
mappings so that an RP that does not support BSR is imported into the BSR. Enabling this feature also allows
an RP positioned outside the enterprise's BSR domain to be learned by the known remote RP on the local
candidate BSR switch.
To configure BSR switches to announce Scope-to-RP mappings, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
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26
Implementing IPv6 Multicast
Configuring BSR Switches to Announce Scope-to-RP Mappings
PurposeCommand or Action
Device# configure terminal
Announces scope-to-RP mappings directly from
the BSR for the specified candidate RP.
ipv6 pim bsr announced rp ipv6-address
[group-list access-list-name] [priority
priority-value]
Step 3
Example:
Device(config)# ipv6 pim bsr announced
rp 2001:DB8:3000:3000::42 priority 0
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 4
Configuring SSM Mapping
When the SSM mapping feature is enabled, DNS-based SSM mapping is automatically enabled, which means
that the switch will look up the source of a multicast MLD version 1 report from a DNS server.
You can use either DNS-based or static SSM mapping, depending on your switch configuration. If you choose
to use static SSM mapping, you can configure multiple static SSM mappings. If multiple static SSM mappings
are configured, the source addresses of all matching access lists will be used.
To use DNS-based SSM mapping, the switch needs to find at least one correctly configured DNS server, to
which the switch may be directly attached.
Note
To configuring SSM mapping, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
Device# configure terminal
Enables the SSM mapping feature for groups
in the configured SSM range.
ipv6 mld ssm-map enable
Example:
Step 3
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27
Implementing IPv6 Multicast
Configuring SSM Mapping
PurposeCommand or Action
Device(config)# ipv6 mld ssm-map enable
Disables DNS-based SSM mapping.no ipv6 mld ssm-map query dns
Example:
Step 4
Device(config)# no ipv6 mld ssm-map query
dns
Configures static SSM mappings.ipv6 mld ssm-map static access-list
source-address
Step 5
Example:
Device(config-if)# ipv6 mld ssm-map
static SSM_MAP_ACL_2 2001:DB8:1::1
Exits global configuration mode, and returns
the switch to privileged EXEC mode.
exit
Example:
Step 6
Device(config-if)# exit
Displays SSM mapping information.show ipv6 mld ssm-map [source-address]
Example:
Step 7
Device(config-if)# show ipv6 mld ssm-map
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 8
Configuring Static Mroutes
Static multicast routes (mroutes) in IPv6 can be implemented as an extension of IPv6 static routes. You can
configure your switch to use a static route for unicast routing only, to use a static multicast route for multicast
RPF selection only, or to use a static route for both unicast routing and multicast RPF selection.
To configure static mroutes, perform this procedure:
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Enters global configuration mode.configure terminal
Example:
Step 2
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28
Implementing IPv6 Multicast
Configuring Static Mroutes
PurposeCommand or Action
Device# configure terminal
Establishes static IPv6 routes. The example
shows a static route used for both unicast
routing and multicast RPF selection.
ipv6 route {ipv6-prefix / prefix-length
ipv6-address | interface-type interface-number
ipv6-address]} [administrative-distance]
[administrative-multicast-distance | unicast |
multicast] [tag tag]
Step 3
Example:
Device(config)# ipv6 route 2001:DB8::/64
6::6 100
Exits global configuration mode, and returns
the switch to privileged EXEC mode.
exit
Example:
Step 4
Device# exit
Displays the contents of the IPv6 multicast
routing table.
show ipv6 mroute [link-local | [group-name |
group-address [source-address | source-name]]
[summary] [count]
Step 5
Example:
Device# show ipv6 mroute ff07::1
Displays the active multicast streams on the
switch.
show ipv6 mroute [link-local | group-name |
group-address] active [kbps]
Example:
Step 6
Device(config-if)# show ipv6 mroute
active
Checks RPF information for a given unicast
host address and prefix.
show ipv6 rpf [ipv6-prefix]
Example:
Step 7
Device(config-if)# show ipv6 rpf
2001::1:1:2
(Optional) Save your entries in the configuration
file.
copy running-config startup-config
Step 8
Using MFIB in IPv6 Multicast
Multicast forwarding is automatically enabled when IPv6 multicast routing is enabled.
Verifying MFIB Operation in IPv6 Multicast
To verify MFIB operation in IPv6 multicast
Implementing IPv6 Multicast
29
Implementing IPv6 Multicast
Using MFIB in IPv6 Multicast
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Displays the forwarding entries and interfaces
in the IPv6 MFIB.
show ipv6 mfib [ | verbose |
group-address-name | ipv6-prefix / prefix-length
| source-address-name | count | interface |
status | summary]
Step 2
Example:
Device# show ipv6 mfib
Displays the contents of the IPv6 multicast
routing table.
show ipv6 mfib [all | linkscope | group-name |
group-address [source-name | source-address]]
count
Step 3
Example:
Device# show ipv6 mfib ff07::1
Displays information about IPv6
multicast-enabled interfaces and their
forwarding status.
show ipv6 mfib interface
Example:
Device# show ipv6 mfib interface
Step 4
Displays general MFIB configuration and
operational status.
show ipv6 mfib status
Example:
Step 5
Device# show ipv6 mfib status
Displays summary information about the
number of IPv6 MFIB entries and interfaces.
show ipv6 mfib summary
Example:
Step 6
Device# show ipv6 mfib summary
Enables debugging output on the IPv6 MFIB.debugipv6 mfib [group-name| gr oup-address]
[adjacency | db | fs | init | interface | mrib
Step 7
[detail] | nat | pak | platform | ppr | ps | signal
| table]
Example:
Device# debug ipv6 mfib FF04::10 pak
Resetting MFIB Traffic Counters
To reset MFIB traffic counters, perform this procedure:
Implementing IPv6 Multicast
30
Implementing IPv6 Multicast
Resetting MFIB Traffic Counters
Procedure
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Enter your password if prompted.
Device> enable
Resets all active MFIB traffic counters.clear ipv6 mfib counters [group-name |
group-address [source-address | source-name]]
Step 2
Example:
Device# clear ipv6 mfib counters FF04::10
Additional References
Standards and RFCs
TitleStandard/RFC
IP Forwarding TableRFC 4292
Management Information Base for the Internet Protocol (IP)RFC 4293
Feature History for IPv6 Multicast
This table provides release and related information for the features explained in this module.
These features are available in all the releases subsequent to the one they were introduced in, unless noted
otherwise.
Feature InformationFeatureRelease
IPv6 multicast allows a host to send a single data
stream to a subset of all hosts (group transmission)
simultaneously
IPv6 multicastCisco IOS XE Everest 16.5.1a
Use the Cisco Feature Navigator to find information about platform and software image support. To access
Cisco Feature Navigator, go to http://www.cisco.com/go/cfn.
Implementing IPv6 Multicast
31
Implementing IPv6 Multicast
Additional References
Implementing IPv6 Multicast
32
Implementing IPv6 Multicast
Feature History for IPv6 Multicast
