SMLT Dual 8600 problem 1

[hpdrifter1]

Hi,

We have a baystack 470 -48t switch connected to two 8600 passport core switces using split MLTs. When both fibre links are initially connected we get connectivity and can ping to and from PCs connected to the switch to anywhere on our extended network. However we can only ping succesfully for 10 minutes befor the ping returns the 'Request timed out' message.

Disconnecting either of the fiber links from the stack and reconnecting it will result in successful pings ... for 10 minutes and then it's the 'Request timed out' message again!!

We suspect that after ten minutes a routing loop occurs but we don't know why! Or why it only happens after 10 minutes.

We would be grateful if anybody could help.

Thanks.

 

[Googer]

How did you configure the trunk to the 470? How many ports are in your trunk? When I first tried this I had a simular problem because you have to set up single port MLTs (MLTs with a single port have to be set up on the port level not under VLAN MLT). I had configured the single port MLTs as standard MLTs with one port and this caused the looping.

If you have more than two ports in the uplink what does it say under VLAN, MLT? It should say "splitMLT".

Is the VLAN that this switch a part of also on the intraswitch trunk? All VLANs that co-exist on the switches must have the IST as part of their VLAN.

Good Luck,

Googer

 

[hpdrifter1]

Thanks Googer. The problem was fixed by removing and rebuilding the IST. The network team got invloved and fixed it.
I'm a bit of a newbie at this 8600 game so your explantion kinda lost me a bit. Could you suggest a site where I can read up on the configuring of these badboys? I'm CCNA qualified but have never dabbled with core switches before.

Once again thanks for your help.

 

[PederChr]

FYI..

If you have a 470 stack with DMLT, there is a bug that has been fix'ed in the latest software.

This bug leads to the los of MLT if a none base boot up before base unit and act as temp base, and you my get a loop.

 

[Googer]

You can download the following from Nortel that might be helpful.

“Network Design Guidelines for Passport 8000 series switch”
“Configuring Switching and Routing Operation for the Passport 8000 series switch using device manager”
“Configuring Layer 2 Operations: VLANs, Spanning Tree, and MultiLink Trunking”

Good Luck

Googer

 

[Googer]

One more.

"Technical Configuration Guide: Configuring Split-MLT"

Good Luck

Googer

 

[hpdrifter1]

Thanks Googer I will logon to the sites right away.

Thanks also to PederChr, your post may exlain something that we experienced a while back!