Virtualization Support; Igmp Vpc Incremental Sync - Cisco Nexus 7000 Series Configuration Manual

Virtualization Support

Link local addresses in the range 224.0.0.0/24 are reserved by the Internet Assigned Numbers Authority
(IANA). Network protocols on a local network segment use these addresses; routers do not forward these
addresses because they have a TTL of 1. By default, the IGMP process sends membership reports only for
nonlink local addresses, but you can configure the software to send reports for link local addresses.
For more information about configuring the IGMP parameters, see Configuring IGMP Interface Parameters.
Virtualization Support
A virtual device context (VDC) is a logical representation of a set of system resources. Within each VDC,
you can define multiple virtual routing and forwarding (VRF) instances. One IGMP process can run per VDC.
The IGMP process supports all VRFs in that VDC and performs the function of IGMP snooping within that
VDC. For information about IGMP snooping, see Configuring IGMP Snooping.
You can use the show commands with a VRF argument to provide a context for the information displayed.
The default VRF is used if no VRF argument is supplied.
For information about configuring VDCs, see the Cisco Nexus 7000 Series NX-OS Virtual Device Context
Configuration Guide.
For information about configuring VRFs, see the Cisco Nexus 7000 Series NX-OS Unicast Routing
Configuration Guide.

IGMP vPC Incremental Sync

The IGMP vPC incremental sync feature enables routes on the virtual port channel (vPC) peer to synchronize
with other routes while the peer link is being established. This feature is a Layer 2 IPv4 multicast feature that
enables faster convergence in vPC topologies. This feature enables Layer 2 Internet Group Management
Protocol (IGMP) states to be synchronized between vPC peer devices in a triggered and incremental manner
instead of periodic synchronization.
Overview of IGMP vPC Incremental Sync
The IGMP vPC Incremental Sync feature sends incremental updates to the peer link using Cisco Fabric Service
(CFS), instead of sending all Join and Leave messages. The routes between peers are synced while the peer
link is being set up.
Figure 11: Sample topology for implementing IGMP vPC Incremental Sync
Peer 1 is a vPC peer that receives the join/query/protocol independent multicast (PIM) hello either from Device
1 or from Device 2, which is on the vPC link. Peer 2 is a vPC peer that receives incremental updates from
Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide
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Configuring IGMP