Contents
- VRRP Aware PIM
- Finding Feature Information
- Restrictions for VRRP Aware PIM
- Information About VRRP Aware PIM
- Overview of VRRP Aware PIM
- How to Configure VRRP Aware PIM
- Configuring VRRP Aware PIM
- Configuration Examples for VRRP Aware PIM
- Example: VRRP Aware PIM
- Additional References for VRRP Aware PIM
- Feature Information for VRRP Aware PIM
VRRP Aware PIM
The Virtual Router Redundancy Protocol (VRRP) eliminates the single point of failure inherent in the static default routed environment. VRRP is an election protocol that dynamically assigns responsibility for one or more virtual routers to the VRRP routers on a LAN, allowing several routers on a multi access link to utilize the same virtual IP address.
VRRP Aware PIM is a redundancy mechanism for the Protocol Independent Multicast (PIM) to interoperate with VRRP. It allows PIM to track VRRP state and to preserve multicast traffic upon fail over in a redundant network with virtual routing groups enabled.
This module explains how to configure VRRP Aware PIM in a network.
- Finding Feature Information
- Restrictions for VRRP Aware PIM
- Information About VRRP Aware PIM
- How to Configure VRRP Aware PIM
- Configuration Examples for VRRP Aware PIM
- Additional References for VRRP Aware PIM
- Feature Information for VRRP Aware PIM
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Restrictions for VRRP Aware PIM
- Only PIM sparse mode (SM) and source specific multicast (SSM) modes are supported. Bidirectional (BiDir) PIM is not supported.
- PIM interoperability with Hot Standby Router Protocol (HSRP) IPv6 is not supported.
- PIM tracks only one virtual group, either Virtual Router Redundancy Protocol (VRRP) or HSRP, per interface.
- VRRP Aware PIM is not supported on a Transit network. PIM redundancy enabled interface does not support the PIM joining the network from down stream.
Information About VRRP Aware PIM
Overview of VRRP Aware PIM
Virtual Router Redundancy Protocol (VRRP) is a redundancy protocol for establishing a fault-tolerant default gateway. The protocol establishes a framework between network devices in order to achieve default gateway failover if the primary gateway becomes inaccessible.
Protocol Independent Multicast (PIM) has no inherent redundancy capabilities and its operation is completely independent of VRRP group states. As a result, IP multicast traffic is forwarded not necessarily by the same device as is elected by VRRP. The VRRP Aware PIM feature provides consistent IP multicast forwarding in a redundant network with virtual routing groups enabled.
In a multi-access segment (such as LAN), PIM designated router (DR) election is unaware of the redundancy configuration, and the elected DR and VRRP master router (MR) may not be the same router. In order to ensure that the PIM DR is always able to forward PIM Join/Prune message towards RP or FHR, the VRRP MR becomes the PIM DR (if there is only one VRRP group). PIM is responsible for adjusting DR priority based on the group state. When a fail over occurs, multicast states are created on the new MR elected by the VRRP group and the MR assumes responsibility for the routing and forwarding of all the traffic addressed to the VRRP virtual IP address. This ensures the PIM DR runs on the same gateway as the VRRP MR and maintains mroute states. It enables multicast traffic to be forwarded through the VRRP MR, allowing PIM to leverage VRRP redundancy, avoid potential duplicate traffic, and enable fail over, depending on the VRRP states in the device.
Virtual Router Redundancy Service (VRRS) provides public APIs for a client to communicate with VRRP. VRRP Aware PIM is a feature of VRRS that supports VRRPv3 (unified VRRP) in both IPv4 and IPv6.
PIM, as a VRRS client, uses the VRRS client API to obtain generic First Hop Redundancy Protocol (FHRP) state and configuration information in order to provide multicast redundancy functionalities.
PIM performs the following as a VRRS client:
How to Configure VRRP Aware PIM
Configuring VRRP Aware PIM
SUMMARY STEPS
1. enable
2. configure terminal
3. fhrp version vrrp version
4. interface type number
5. ip address address
6. vrrp group id address-family ipv4
7. vrrs leader group name
8. vrrp group id ip ip address
9. exit
10. interface type number
11. ip pim redundancy group name vrrp dr-priority priority-value
12. end
DETAILED STEPS
Additional References for VRRP Aware PIM
Related Documents
Technical Assistance
Description
Link
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Feature Information for VRRP Aware PIM
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1 Feature Information for VRRP Aware PIM Feature Name
Releases
Feature Information
VRRP Aware PIM
Cisco IOS XE Release 3.10S
VRRP Aware PIM is a redundancy mechanism for the Protocol Independent Multicast (PIM) to interoperate with VRRP. It allows PIM to track VRRP state and to preserve multicast traffic upon failover in a redundant network with virtual routing groups enabled.
No commands were introduced or modified.