5510 management IP not responding

[HungryHouse]

Hi all, this is somewhat of a continuation of thread902-1158836, however, my issue is a tad different:
VLAN 1= 192.168.1.x
VLAN 16= 192.168.16.x

Other switches
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VLAN1----8600---VLAN16---Other switches
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PC PC 5510 stack
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PC

From the PCs on VLAN 1 (which use 8600 as their dg), VLAN16 switches can all be reached however we recently moved over the 5510 from the VLAN1 subnet to the VLAN16 subnet and made all appropriate config changes. (I was hitting the 5510 management address just fine under vlan1/192.168.1.x)
Essentially the 5510 is set up in the same manner as all other switches (8600 connecting port is untagged but get a pvid of 16..I dont tag anywhere on vlan16)
All works well. on that subnet with an address in the 192.168.16.x range.
VLAN1 PCs can ping all the way through to the PC on the 5510 however we can not ping the 5510 stack itself, nor can the 5510 itself ping anything on VLAN1, however, the PC on the 5510 can ping anything on VLAN1.
Keep in mind that the 8600 can ping the 5510 and vice-versa.

I have checked the ARP tables everywhere, all looks correct.
I have rebooted 5510 and 8600, I have turned off IGMP proxy and snoop on the 5510. I have made sure queue-set=4, i have played with auto-neg settings..to no avail.

Anyone have any suggestions/thoughts?

Note: 5510= code 4.2.1
8600 code= 3.5.9

Your suggestions/fixes are appreciated.

 

[HungryHouse]

We found a wierd connection between IP forwarding (Ip routing) on the 5510 and this issue. When IP forwarding is enabled (which it was for this because of some static routes and such), we could NOT hit the management IP.
With IP forwarding disabled, we could indeed hit the 5510 nmnmt IP from the workstations on vlan1.
We have left it like this for the moment, and I have a case open with Nortel.
I though y'all would want to know. The results are consistent.

 

[telecom116]

Keep us updated. At this time I have one 5520 with routing enabled and a whole bunch of 5510s and 5520s around and the number is growing.