Interoperability Between HSRP and MSHRP and NT 5.0 and HP AdvanceStack

Problem description

How Does Cisco Hot Standby Routing Protocol (HSRP) or multi-Hot Standby Router Protocol (MSHRP) use the internal Group Management Protocol (IGMP) to interoperate with Microsoft NT 5.0 and HP AdvanceStack or ProCurve switches?

Solution

The two routers are connected to two different vswitch ports. HSRP and MSHRP use IP multi-point transmission datagram to ensure that one of the routers can be used as a backup when other routers fail. One or more NT services are connected to the vswitch ports instead of the two ports used by the vro.

When the NT Server is connected to the switch, it sends an IGMP connection message to the switch (specify the Cisco HSRP/MSHRP address 224.0.0.2, this is the only vswitch port that is added to the multicast group, because Cisco routers have never been added to this group (they only use multicast addresses ). Then, the switch stops forwarding data to other ports, including routers. This is the correct IGMP behavior for vswitches. The problem is that Cisco routers no longer receive HSRP/MSHRP packets from each other, so the Protocol cannot work normally.

In this case, the following steps are used as an escape method:

1. Configure the HP switch to block or forward IP address multi-point transfer traffic on each port, regardless of IGMP.
2. Specify Forward (opposite to Auto or Blocked) in the IGMP configuration of the switch that directly connects two (M) HSRP router ports.
This change enables the switch to forward all multicast traffic between these ports.
Note: This is a switch IGMP configuration item, rather than a switch traffic/security filter.
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[A5551807/TRAK-ACTIVE/English] A5551807
Cisco: interoperability of HSRP and MSHRP w/NT 5.0 and HP AdvanceStack
Problem Description
How does the Cisco Hot Standby Routing Protocol (HSRP) or Multiple Hot
Standby Router Protocol (MSHRP) interoperate with Microsoft NT 5.0, and
HP AdvanceStack or ProCurve switch, with Interior Group Management
Protocol (IGMP )?
Solution
Two routers are connected to two different switch ports. HSRP and MSHRP
Use IP multicast into Rams to ensure that one of the routers is available as a backup in case the other router goes down. one or more NT servers are connected to switch ports other than the two used by the routers.
When the NT server is connected to the switch, it sends an IGMP join
Message to the switch (specifying Cisco's HSRP/MSHRP address 224.0.0.2 ).
At this point, this is the only switch port joined to that multicast group, since Cisco routers never perform a join to this group (they simply use the multicast address ). subsequently, the switch stops forwarding to the other ports, including those to the routers.
This is correct IGMP behavior on the part of the switches.
The problem is that the Cisco routers no longer receive each other's HSRP/MSHRP packets, so the protocol cannot work properly.
Use these steps as a work-around for this behavior:
1. Configure HP switches to block or forward IP multicast traffic on individual ports, regardless of IGMP.
2. Specify Forward (as opposed to Auto or Blocked) in the switch's IGMP configuration on the ports which directly connect the two (M) HSRP routers.
This change causes the switch to forward all multicast traffic between those ports.
Note: This is a switch IGMP configuration item, not a switch Traffic/Security filter.