HP, Cisco switch issues?

[poh]

Here's a quick diagram of what we have:

Cisco 3508 (Distribution)

|

| 1GB Fiber connection

|

HP 4000 (Access)

Are there issues to be concerned of when interconnecting a cisco switch to an HP switch - i.e. spanning tree, trunking, etc. - that will cause connectivity problems? Please advise how I can avoid.

Thanks in advance...

[glen.grant]

Shouldn't be as long as you are familiar with the different command structures . HP even supports CDP so that is a plus . Being a single connection you shouldn't have to worry about spanning tree issues , should be pretty straight forward unless you are getting into like trunking multiple vlans down to the HP or something like that then it becomes a little more difficult .

[poh]

Glen thanks,

Here's the situation we're having. Our users are plugged into the hp switch. They're using cisco vpn client to connect to a vendor's site in order to run a web-based application. Our users are experiencing random slowness on their pc's running this app. One user has slowness, but another doesn't. Very odd. I checked both the hp and cisco switches' counters and logs to see if there are any errors, issues, etc. I find none at all. No bandwidth nor utilization issues too. During the slowness, I run a ping and traceroute from their pc's and I get 30ms returns. Good connectivity end to end.

The vendor is claiming it's a spanning tree issue. I agree as you (Glen) said, there is no concern for spanning tree for a single link. However, he claims that spanning tree packets are still being transmitted by the cisco switch possibly causing the slowness and can be remedied by disabling something in spanning tree which he couldn't remember at the time. I agree with him except I'm not convinced that the spanning tree packets are the cause of slowness. If it were, all the users' connections should experience slowness. On the contrary, they don't. Internet browsing, email, etc. works fine except for the web-app running over vpn. Bottom line: I don't think it's a network or switch issue. I even ran mrtg and the peak never goes above 8mbs.

Thoughts anyone?

Thanks in advance...

[milan.kulik]

Hi,

is the line between the Cisco and HP switches a trunk (multiple VLANs) or an access line (one VLAN)?

If it's an access line, there should definitely be no problem with STP BPDUs (one frame per 2 seconds with default parameters).

And I agree if this were a network problem, it should not bother only one user.

For trunk line STP details see

http://www.cisco.com/warp/customer/473/103.html#stp

Regards,

Milan

[paddyxdoyle]

Hi,

It sounds like an application type issue.

Can you connect a PC to anywhere else in your network and test the VPN from there such as your network core or even a spare interface on your router/firewall. i.e. none HP switch?

Also i have come across issues before integrating HP switches with Cisco networks, this may not be relevant in your case, however we used HP switches in blade centres connecting into 2 x 6500 switches The HP switches only supported mono spanning tree which caused us problems as we were running PVST and wanted to use multiple VLANs on the blade servers.

HTH

Paddy

[poh]

Hi Paddy,

Thanks for your response. My colleague is working on that. In fact, yesterday he informed me he had replaced the NIC card on one problem pc. Apparently so far it's helped. However, we're waiting for results. We're using the default vlan and no other (multiple) vlans.

Thanks...

[poh]

Hi Milan,

Thanks for the response. We have it as an access line.

Thanks...