3.3. IGMP Configuration Command Reference

This command enables the Internet Group Management Protocol (IGMP) context. When the context is created, the IGMP protocol is enabled.

The Internet Group Management Protocol (IGMP) is used by IPv4 systems (hosts and routers) to report their IP multicast group memberships to neighboring multicast routers. An IP multicast router can be a member of one or more multicast groups, in which case it performs both the “multicast router part” of the protocol which collects the membership information needed by its multicast routing protocol, and the “group member part” of the protocol which informs itself and other neighboring multicast routers of its memberships.

The no form of the command disables the IGMP instance. To start or suspend execution of IGMP without affecting the configuration, use the no shutdown command.

This command enables IGMP on a group-interface in a VRF context. Activating IGMP under the group-interface is a prerequisite for subscriber replication. The group-interface is also needed so that MCAC can be applied and various IGMP parameters defined.

This command can be used in a regular, wholesaler or retailer type of VRF. The retailer VRF does not have the concept of group-interfaces under the subscriber-interface hierarchy. In the case that this command is applied to a retailer VRF instance, the optional fwd-service command must be configured. The fwd-service command is referencing the wholesaler VRF in which the traffic is ultimately replicated. Redirection in the retailer VRF is supported.

This command enables IGMP on a group-interface in the Global Routing Table (GRT). The group-interface in GRT is defined under the IES service. Activating IGMP under the group-interface is a prerequisite for subscriber replication. The group-interface is also needed so that MCAC can be applied and various IGMP parameters defined.

This command disables the router alert checking for IGMP messages received on this interface.

The no form of the command enables the IGMP router alert check option.

This command applies the referenced IGMP policy (filter) to an interface subscriber or a group-interface. An IGMP filter is also known as a black/white list and it is defined under the config>router>policy-options.

When redirection is applied, only the import policy from the subscriber will be in effect. The import policy under the group interface is applicable only for IGMP states received directly on the SAP (AN in IGMP proxy mode).

The no form of the command removes the policy association from the IGMP instance.

This command specifies the maximum number of groups for which IGMP can have local receiver information based on received IGMP reports on this interface. When this configuration is changed dynamically to a value lower than the currently accepted number of groups, the groups that are already accepted are not deleted. Only new groups will not be allowed. This command is applicable for IPv4 and IPv6.

The no form of the command sets no limit to the number of groups.

This command configures the maximum number of group sources for which IGMP can have local receiver information based on received IGMP reports on this interface. When this configuration is changed dynamically to a value lower than currently accepted number of group sources, the group sources that are already accepted are not deleted. Only new group sources will not be allowed.

The no form of the command reverts to the default.

This command configures the maximum number of group sources for this group-interface.

This command configures the query source IP address for the group interface. This IP address overrides the source IP address configured at the router level.

The no form of the command removes the IP address.

The shutdown command administratively disables the entity. When disabled, an entity does not change, reset, or remove any configuration settings or statistics. Many entities must be explicitly enabled using the no shutdown command and must be shut down before they may be deleted.

Unlike other commands and parameters where the default state is not indicated in the configuration file, shutdown and no shutdown are always indicated in system generated configuration files.

The no form of the command puts an entity into the administratively enabled state.

This command disables the processing of IGMP messages outside of the subscriber-host context. No other hosts outside of the subscriber-hosts can create IGMP states.

Disabling this command allows the creation of the IGMP states that correspond to the AN that operate in IGMP proxy mode. In this mode, the AN will hide source IP addresses of IGMP messages and will source IGMP messages with its own IP address. In this case, an IGMP state can be created under the sap context. This IGMP state creation under the SAP is controlled via the import policy under the group-interface.

The IGMP state processing for regular subscriber-hosts is unaffected by this command.

The no form of the command disables the command.

This command enables subnet checking for IGMP messages received on this interface. All IGMP packets with a source address that is not in the local subnet are dropped.

This command specifies the IGMP version. If routers run different versions of IGMP, they will negotiate the lowest common version of IGMP that is supported by hosts on their subnet and operate in that version. For IGMP to function correctly, all routers on a LAN should be configured to run the same version of IGMP on that LAN.

For IGMPv3, a multicast router that is also a group member performs both parts of IGMPv3, receiving and responding to its own IGMP message transmissions as well as those of its neighbors.

This command configures the query source IP address for all group interfaces.

The no form of the command removes the IP address.

This command enables the context to configure an IGMP interface. The interface is a local identifier of the network interface on which reception of the specified multicast address is to be enabled or disabled.

The no form of the command deletes the IGMP interface. The shutdown command in the config>router>igmp>interface context can be used to disable an interface without removing the configuration for the interface.

This command specifies the frequency that the querier router transmits general host-query messages. The host-query messages solicit group membership information and are sent to the all-systems multicast group address, 224.0.0.1.

This command configures the frequency at which the querier sends group-specific query messages including messages sent in response to leave-group messages. The lower the interval, the faster the detection of the loss of the last member of a group.

This command specifies how long the querier router waits to receive a response to a host-query message from a host.

This command configures the interface as a member of a redundant pair for multicast traffic.

The no form of the command removes the configuration.

This command enables the context to configure group ranges which are translated to SSM (S,G) entries. If the static entry needs to be created, it has to be translated from a IGMPv1 IGMPv2 request to a Source Specific Multicast (SSM) join. An SSM translate source can only be added if the starg command is not enabled. An error message is generated if you try to configure the source command with starg command enabled.

This command is used to configure group ranges which are translated to SSM (S,G) entries.

This command specifies the source IP address for the group range. Whenever a (*,G) report is received in the range specified by grp-range start and end parameters, it is translated to an (S,G) report with the value of this object as the source address.

This command tests multicast forwarding on an interface without a receiver host. When enabled, data is forwarded to an interface without receiving membership reports from host members.

This command enables the context to add a static multicast group either as a (*,G) or one or more (S,G) records. Use IGMP static group memberships to test multicast forwarding without a receiver host. When IGMP static groups are enabled, data is forwarded to an interface without receiving membership reports from host members.

When static IGMP group entries on point-to-point links that connect routers to a rendezvous point (RP) are configured, the static IGMP group entries do not generate join messages toward the RP.

This command specifies a IPv4 unicast address that sends data on an interface. This enables a multicast receiver host to signal a router the group to receive multicast traffic from, and from the source(s) that the traffic is expected.

The source command is mutually exclusive with the specification of individual sources for the same group.

The source command in combination with the group is used to create a specific (S,G) static group entry.

The no form of the command removes the source from the configuration.

This command adds a static (*,G) entry. This command can only be enabled if no existing source addresses for this group are specified.

Use the no form of the command to remove the (*,G) entry from the configuration.

This command configures the robust count. The robust-count variable allows tuning for the expected packet loss on a subnet. If a subnet anticipates losses, the robust-count variable can be increased.

This command creates a tunnel interface associated with an RSVP P2MP LSP. IPv4 multicast packets are forwarded over the P2MP LSP at the ingress LER based on a static join configuration of the multicast group against the tunnel interface associated with the originating P2MP LSP. At the egress LER, packets of a multicast group are received from the P2MP LSP via a static assignment of the specific <S,G> to the tunnel interface associated with a terminating LSP.

At ingress LER, the tunnel interface identifier consists of a string of characters representing the LSP name for the RSVP P2MP LSP. The user can create one or more tunnel interfaces in PIM and associate each to a different RSVP P2MP LSP. P2mp-ID is required to configure LDP P2MP LSP tunnel interfaces. Sender address for a tunnel interface must be specified only on the leaf node.

At egress LER, the tunnel interface identifier consists of a couple of string of characters representing the LSP name for the RSVP P2MP LSP followed by the system address of the ingress LER. The LSP name must correspond to a P2MP LSP name configured by the user at the ingress LER. The LSP name string must not contain “::” or “:” at the end of the LSP name. However, a single “:” can be used anywhere in the string except at the end of the name.

This command provides the context to configure static multicast receiver hosts on a tunnel interface associated with an RSVP P2MP LSP.

When enabled, data is forwarded to an interface without receiving membership reports from host members.

This command enables the context to add a static multicast group either as a (*,G) or one or more (S,G) records.

The user can assign static multicast group joins to a tunnel interface associated with an RSVP P2MP LSP.

A given <*,G> or <S,G> can only be associated with a single tunnel interface.

A multicast packet which is received on an interface and which succeeds the RPF check for the source address will be replicated and forwarded to all OIFs which correspond to the branches of the P2MP LSP. The packet is sent on each OIF with the label stack indicated in the NHLFE of this OIF. The packets will also be replicated and forwarded natively on all OIFs which have received IGMP or PIM joins for this <S,G>.

The multicast packet can be received over a PIM or IGMP interface which can be an IES interface, a spoke SDP terminated IES interface, or a network interface.

This command specifies a IPv4 unicast address of a multicast source. The source command is mutually exclusive with the specification of individual sources for the same group. The source command in combination with the group is used to create a specific (S,G) group entry in a static group join on a tunnel interface associated with a P2MP RSVP LSP.

The no form of the command removes the source from the configuration.

This command adds a static (*,G) group entry in a static group join on a tunnel interface associated with a P2MP RSVP LSP.

This command can only be enabled if no existing source addresses for this group are specified.

The no form of the command removes the (*,G) entry from the configuration.