Configure IPv4 Multicast
Configure IPv4 multicast for an Advanced Routing Engine.
The Advanced Routing Engine supports IPv4 multicast for a logical router. You should be familiar with IP Multicast, IGMP, and PIM concepts.
IPv4 multicast on an Advanced Routing Engine supports features not supported on the legacy routing engine:
- IGMP static join, which is the ability to specify a static IGMPv3 or IGMPv2 receiver on an interface. The corresponding PIM Join message is sent upstream.
- Protocol Independent Multicast (PIM) supports Reverse-Path Forwarding (RPF) lookup modes: MRIB only, URIB only, and MRIB-then-URIB.
IPv4 multicast does not support IGMPv1.
When you configure IPv4 multicast, you Create Multicast Routing Profiles for PIM interface timers and IGMP interface queries to make your configuration easier and consistent. You can create multicast route maps to control PIM group permissions.
You can also Create an IPv4 MRoute if you want unicast traffic to take a different route from multicast traffic.
- Selectand select a logical router.NetworkRoutingLogical Routers
- SelectMulticastandenable multicast protocol.
- Configure general PIM parameters for the logical router.
- Select theRPF lookup mode, which determines where the logical router looks to find the outgoing interface to reach the source address contained in the multicast packet. If the outgoing interface stored in the RIB matches the interface on which the multicast packet arrived, the logical router accepts and forwards the packet; otherwise, it drops the packet.
TheRPF lookup modealso controls where to do route lookup to select the route to use for the PIM Join.
- mrib-only—Look in multicast RIB only.
- mrib-then-urib—Look in multicast RIB first; if route is not present in multicast RIB, then look in unicast RIB.
- urib-only—Look in unicast RIB only.
- For theInterface General Timer, select a PIMInterface Timer Profileor create a new IPv4 PIM Interface Timer profile; default isNone.
- Specify theRoute Age Out Time (sec)—the number of seconds that a multicast route remains in the mRIB after the session ends between a multicast group and a source; range is 210 to 7,200; default is 210.
- To configure Source-Specific Multicast (SSM), inMulticast SSM Rangeselect a prefix list (or create a new one) that specifies the source addresses allowed to deliver multicast traffic to the receiver; default isNone (no prefix list).
- To configure the Shortest-Path Tree (SPT) threshold for a multicast group or prefix,AddaGroup Address(multicast group or prefix for which you are specifying the distribution tree) by selecting a Prefix List or creating a new one.
- Specify theThresholdrate in kilobits per second (kbps); if multicast traffic for the multicast group/prefix arrives at the logical router faster than this threshold rate, routing to the specified group/prefix switches from shared tree (sourced from the Rendezvous Point [RP]) to SPT distribution:
- 0 (switch on first data packet)(default)—The logical router switches from shared tree to SPT for the group/prefix when the logical router receives the first data packet for the group/prefix.
- Enter the total number of kilobits per second that can arrive for the multicast group/prefix at any interface and over any time period, upon which the logical router switches to SPT distribution for that multicast group or prefix; range is 0 to 4,294,967,295.
- never (do not switch to spt)—The PIM router continues to use the shared tree to forward packets to the multicast group/prefix.
- Specify PIM group permissions to control which PIM Join messages and Register messages the logical router accepts, and which multicast traffic the logical router forwards.
- Select.PIMGroup Permissions
- To control packets to certain destination multicast groups from certain sources (S,G) to transit the logical router, forSource Group List, select an Access List that you created or create a new one. The access list can be an extended access list where the source specifies the multicast source and the destination specifies the multicast group. Default isNone (no access list).When you modify PIM Group Permissions by removing or changing the Source Group access list, the new permission does not retroactively clear multicast routes form the multicast RIB table (mRIB) or multicast FIB table (mFIB) for existing flows. To change entries for existing flows in the mRIB or mFIB, you would need to force a Leave or clear mroute entry.
- Configure PIM characteristics for an interface.
- SelectandPIMInterfacesAddan interface byName.
- Enter a helpfulDescriptionof the interface.
- Specify theDR Priority(Designated Router priority) of the interface to control which router forwards PIM Join messages, PIM Register messages, and Prune messages to the Rendezvous Point (RP); range is 1 to 4,294,967,295; default is 1. Of the PIM devices on a LAN, if DR Priority is configured, the device with the highest priority value is elected the DR.
- Send BSMto allow propagation of Bootstrap Messages (enabled by default).The Advanced Routing Engine cannot act as a BSR, but can send and relay BSM messages.
- TheTimer Profilefor the interface is inherited from the General PIM section unless you override that by selecting an IPv4 PIM Interface Timer profile; default isNone.
- Specify aNeighbor Filterusing an access list you created or create a new access list to specify the prefixes of devices that are allowed to become or denied from becoming PIM neighbors of the logical router.
- (ASM only) Configure a PIM Rendezvous Point (RP) for an Any-Source Multicast (ASM) environment.You can configure a Candidate RP and a Static RP; they are not mutually exclusive.
- Select.PIMRendezvous Point
- Select the localRP Type:Static RPorCandidate RP; default isNone.
- If you chooseStatic RP, this establishes a static mapping of an RP to multicast groups. You must explicitly configure the same RP on other PIM routers in the PIM domain. Configure the following:
- Select the RPInterfacewhere the RP receives and sends multicast packets. Valid interface types are Layer3 interfaces (which include Ethernet, VLAN, loopback, Aggregate Ethernet (AE), tunnel, and subinterfaces).
- Select theAddressof the interface; the IP addresses of the interface you selected populate the list.
- SelectOverride learned RP for the same groupso that this static RP serves as RP instead of the RP elected for the groups in the Group List.
- Specify theGroup Listof multicast groups for which the static RP acts as the RP by selecting an Access List or creating a new access list. Default isNone (no access list).
- If you chooseCandidate RP:
- Select theInterfacewhere the candidate RP receives and sends multicast packets. Valid interface types are Layer3 interfaces (which include Ethernet, VLAN, loopback, Aggregate Ethernet (AE), tunnel, and subinterfaces).
- Select theAddressof the interface.
- Specify thePriorityof the candidate RP; range is 0 to 255; default is 192. A lower priority value indicates a higher priority.
- Specify theAdvertisement Interval, the frequency (in seconds) at which the candidate RP sends advertisements to other routers; range is 1 to 26,214; default is 60.
- To control the groups that the candidate RP accepts, select aGroup List, which is an IPv4 access list you created, or create a new access list. Default isNone (no access list). If no access list is applied, the logical router starts advertising itself as the RP for all groups.
- AddanIPv4 Addressof the remote (external) RP.
- Select aGroup Listto specify the multicast groups for which the remote RP acts as the RP or create a new access list. Default isNone (no access list).
- SelectOverrideif you want the remote RP you statically configured to serve as RP instead of an RP that is dynamically learned (elected) for the groups in the Group List.
- ClickOKto save PIM settings.
- Configure IGMP on interfaces that face a multicast receiver.
- SelectIGMPandenable IGMP.
- To configure a dynamic IGMP interface, selectDynamic.
- AddanInterfaceby selecting one from the list.
- Select the IGMPVersion:2or3.
- Select theRobustnessvalue in the range 1 to 7; default is 2.The (Robustness * QueryInterval) + MaxQueryResponseTime determines how long a Join message is valid on the logical router. If the logical router receives a Leave Group message, Robustness * LastMemberQueryInterval is the length of time that the logical router waits before deleting the Leave Group entry. Increase the Robustness value if the subnet on which this logical router is located is prone to losing packets. For Join messages, a Robustness value of 1 is ignored. For Leave Group messages, the logical router uses the Robustness value as the Last Member Query Count also.
- ForGroup Filter, select an access list or create a new access list to control the sources and groups for which the interface will accept IGMP Joins; default isNone (no access list).
- ForMax Groups, enter the maximum number of groups that IGMP can process simultaneously for the interface. Range is 1 to 65,535; default isunlimited, which means the highest value in the range.
- ForMax Sources, enter the maximum number of sources that IGMP can process simultaneously for the interface. Range is 1 to 65,535; default isunlimited, which means the highest value in the range.
- ForQuery Profile, select an IGMP Interface Query profile you created or create a new one to apply to the interface; default isNone.
- Selectdrop IGMP packets without Router Alert optionto require that incoming IGMPv2 or IGMPv3 packets have the IP Router Alert Option, RFC 2113, or they will be dropped. (Default is disabled.)
- ClickOKto save the dynamic IGMP interface.
- To configure a static IGMP interface, selectStatic.
- Adda static interface byName.
- Select theInterfaceto be the static IGMP interface.
- Enter the multicastGroup Addressof the static IGMP members.
- Enter theSource Addressof the sender transmitting multicast traffic to the multicast group (S,G). Traffic for this (S,G) combination is allowed on the static IGMP interface.
- ClickOKto save the static IGMP interface.
- ClickOKto save the multicast configuration.