問題描述

Cisco熱備路由協議(HSRP)或多熱備路由器協議(MSHRP)如何使用內部組治理協議(IGMP)與Microsoft NT 5.0和HP AdvanceStack或PRoCurve交換機互操作？

解決方法

兩個路由器與兩個不同的交換機端口連接，HSRP和MSHRP使用ip多點傳送數據報來確保在其它路由器故障時，其中的一個路由器可以用作備份。一個或多個NT服務與交換機端口、而不是路由器使用的兩個端口連接。

當NT服務器與交換機連接時，它向交換機發送一個IGMP連接消息(指定Cisco的HSRP/MSHRP地址224.0.0.2)，這時，這是加入該多點傳送組的唯一的一個交換機端口，因為Cisco路由器從來沒有加入這個組(它們只是使用多點傳送地址)。隨后，交換機停止向其它端口轉發，包括路由器。對交換機而言，這是正確的IGMP行為。問題在于Cisco路由器不再互相接收HSRP/MSHRP數據包，因此協議無法正常工作。

對于這種情況，使用下面的步驟作為規避方法：

1. 配置惠普交換機封鎖或轉發各個端口上的IP多點傳送流量，不考慮IGMP。

2. 在直接連接兩個(M)HSRP路由器的端口的交換機IGMP配置中指定Forward (與Auto或Blocked)相反。

這個變化使交換機在這些端口之間轉發所有的多點傳送流量。

注：這是一個交換機IGMP配置項，而不是交換機流量/安全性過濾器。

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.........following with all English text ....

[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 datagrams 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.