[c-nsp] Microsoft multicasted cluster vs. Cisco IOS

[Olivier Dauby]

Hi *,

I have a 3 Microsoft servers running in cluster facing 2 Cisco routers on an Ethernet segment. The routers allow remote sites to gain access to the cluster.

Problem is that remote users can't gain access to the cluster, but local users can.

The Microsoft cluster is supposed to listen on a virtual ip address using a multicast mac address. Local users see the virtual ip of the cluster (10.106.49.6) with a mac address 03:BF:0A:6A:31:06. I'm already a bit confused here since I expected the multicast mac address to begin with 0x01 instead of 0x03.

The routers also seem to be confused, they have been unable to learn this mac address as you can see in this 'show arp' output:

Protocol  Address          Age (min)  Hardware Addr   Type   Interface
<snip>
Internet  10.106.49.6             0   Incomplete      ARPA
<snip>

This jeopardizes remote users to ever gain access to this ip.

I quickfixed this with a dirty 'arp' command on both routers:

	arp 10.106.49.6 03BF.0A6A.3106 arpa

Is there a nicer (read : more dynamic) way to solve this issue?

The two routers are:
cisco 7206VXR (NPE300) processor (revision B) with 122880K/40960K bytes of memory.
IOS (tm) 7200 Software (C7200-JS-M), Version 12.2(21a), RELEASE SOFTWARE (fc2)
and
cisco 3620 (R4700) processor (revision 0x81) with 26624K/6144K bytes of memory.
IOS (tm) 3600 Software (C3620-D-M), Version 12.2(24), RELEASE SOFTWARE (fc1)

TIA!

O.