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Author Topic: Nortel/Avaya 5500 Stack Routing Issue  (Read 3331 times)

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Offline majid0403

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Nortel/Avaya 5500 Stack Routing Issue
« on: September 24, 2013, 05:30:06 AM »
Hi All,

This is my first post here! Great forum with loads of good info.

We have got a Stack of 6 Nortel 5500 Switches running FW: SW:v5.1.4.021.


IP Routing enabled globally
5 L3 VLANs configured (Routing enabled on the interfaces)
Default-gateway pointing to a.a.a.a
Static Default Route pointing to a.a.a.a (Where a.a.a.a is our WAN Router)

 I thought we only needed a default route if we are running the stack in L3, but as this stack was built by a 3rd party and almost 3 years ago no configuration changes were made since then.

I was working on a change last night were we had to do the following

Add 4 new Static Routes Pointing to a.a.a.a
Add a new default Route Pointing to b.b.b.b (where b.b.b.b was our Firewall)

I made the changes in this order:

Added the 4 new Static Routes
Deleted the old default route and default gateway
Added the new default route (as the stack is running in L3, I didnt add the default-gateway)
Everything was working fine, no services were affected.

However after this change I have noticed that I cannot Ping the VLAN gateways of the stack from the remote sites. All services are running as normal, I can even traceroute/ssh/snmp to the vlan gateways but just cannot ping them. Very very strange, never saw this in my life before ......

There are no Firewalls or ACL's so nothing is being blocked anywhere.

I tried adding the default-gateway pointing to the new b.b.b.b (but still cannot ping the vlan gateways). Services remain unaffected.

However if I rollback and just leave the default route pointing to old a.a.a.a, services are still unaffected but we cannot ping the vlan gateways.

If I rollback and leave the default route and default-gateway pointing to the old a.a.a.a, I can now ping the vlan gateways..

Please help! I am pulling my hair out here ........

Offline TankII

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Re: Nortel/Avaya 5500 Stack Routing Issue
« Reply #1 on: September 26, 2013, 09:09:04 AM »
Eek!  5.1.4 - lots of bugs.  Couldn't wait to get off it once 6.X arrived.
Things like DHCP limitations in an L-3 environment, etc.
I would get the stack up to 6.2.6 and re-test.

Of note:  The remote location might not be able to respond to pings if the routes are not changed to reflect the changes you made on your side.


Offline Michael McNamara

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    • michaelfmcnamara
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Re: Nortel/Avaya 5500 Stack Routing Issue
« Reply #2 on: September 30, 2013, 08:23:44 PM »
There are a number of well known issues with static routes in the 5.x and even in the early 6.x software branches.

A reboot of the switch/stack will help you quickly identify and/or eliminate that as the potential problem.

The obvious question would be... b.b.b.b knows how to get to these remote subnets and has routes to them?

If there are no routes in b.b.b.b for the remote subnets and/or the firewall policy doesn't allow ICMP redirects then you are going to have basic routing issues.

Good Luck!
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