Linking 6509 to 4507

[kcbell]

I have done a network upgrade project to install (2) 6509 and (2) 4507. The up links from the 4507 is from the Supervisor Module 1/1 to one of the Ethernet port on the 6509-1 and 1/2 to one the Ethernet port on the 6509-2.

Recently I hired a network consultant to review the design and he said the proper way to link two switches is NOT to use the Supervisor Module Ethernet port. A regular Ethernet port on a Ethernet blade should be used.

I would like to hear from others. Please comment!

Thanks

 

[vipergg]

I don't see where it would make a whole lotof difference , did they give you a reason for their thinking ? They wouldn't put the ports there if they didn't want you to use them.

 

[MLC7]

What Supervisor Engine are you running? Usually those management ethernet ports are just 10/100. A better way to link them is with the Gigabit uplink ports. GBIC or SFP.

 

[kcbell]

MLC7: They are Supervisor V.

His reason was if the Supervisor module failed then the up link would fail as well. If the inter switch links are at the port blade then the Hot Standby Supervisor would take over and you only get a SNMP trap to tell you the Hot Standby now is in Active state. Everything is automatic.

The problem we experienced was the Supervisor 1 Ethernet port failed. When I physically unplugged the cables from 1/1 and ½ and did a “sh inter status”, the status showed “connected”. I have to physically pull Supervisor 1 then the network recovered.

The consultant was not the one that design the inter link. However, he said he always use the Gigibit port for inter link instead of the ports on the Supervisor module.

Kcbell

 

[MLC7]

Yes it's probably best to get the links off of the SUP Modules all together if possible. Gig ports are the best especially if you have two then you can create an Etherchannel and double your bandwidth on the links.

 

[voltron1011]

This is interesting info... We had a SUP module go down in one of our corp switches (with uplinks attached) and wreaked havok on our network... I need to look into getting these uplinks off.
Anyone have any documentation for that?

 

[kcbell]

voltron1011:

We used to have two 5500 linked together on the Ethernet port on the supervisor module. When the superivosr failed, it could not switch over because the link was failed as well. If I had done the link on the 24 port blade then HSRP would switch the control to the Hot Sandby Supervisor. Everything would be fine with no interruption.

Regarding implementation, I haven't done it yet.

Questions: Is this a "Best Practice" from Cisco? If it is, why do they design Ethernet ports on the supervisor blade?

kcbell

 

[BuckWeet]

use port channels across both supervisors.. that gives you blade redundancy..

 

[voltron1011]

Ok, I double checked my setup and on our 6500's we have dual SUPs with the port channels split 50/50 in between them. Our 4500's are all single SUP, so it doesn't matter if it fails because the whole switch will be down anyways.