Mitel 3300 ICP and Cisco GLBP

[chaeb35lt]

We have a network of 3300 ICPs mostly MX and MXe and mostly on sw 8.0 UR4.

Previously Cisco HSRP (Hot Standby Routing Protocol) has been used to provide LAN router redundancy but recently two sites, both using sw 8.0 UR4, have been deployed using GLBP (Gateway Load Balancing Protocol). At these two site the ICPs are generating the following log entries:

Log Number: 3936
Date: 2009/Apr/03
Time: 15:24:24
Source: Duplicate IP Address Detector
Description: Maintenance: Category(General); msgFormatId(0) Possibly 2 computers with the same IP address (10.xx.xx.1). One of those computers has MAC address 00:07:xx:xx:xx:01. If this IP is used by the Mitel RTC card, E2T card, a phone or router, there may be disruption in telephone service.

Has anyone any experience of implementing GLBP with Mitel 3300 ICPs?

 

[IrwinMFletcher]

Are there in fact two devices with that IP address?

 

[chaeb35lt]

Hi, IrwinMFletcher, no - only in so much as there are two Cisco routers (CAT 4500 switches) running GLBP. The Cisco description is that GLBP will respond to ARP requests from different hosts with a different MAC address for the default router address.

This is normal GLBP operation but the Mitel is not happy - either the ICP is reading all ARP replies (unlikely - it is a switched infrastructure) or GLBP is changing the MAC address that it supplies to the Mitel ICP.

Any experience with ICPs and GLBP?

 

[IrwinMFletcher]

The E2T will arp a phone's IP address to determine the MAC address to use in the streaming. If the router responds with a different MAC than that already in the arp table, then the system will complain.

 

[kwbMitel]

A customer of mine just disabled the ARP responses from 1 side to avoid this issue.

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