Strange LACP/Trunk problem

[Sam Fewster]

I have an HP 2650 Switch, with a static LACP trunk running over ports 49-50 to a Dell switch. There are a few devices plugged into the switch also.

The problem I am having is that when both ports (49 & 50) are up, some IP addresses cannot be found from the Dell switch (Ping, traceroute e.t.c). When one port is physically unplugged or disabled, everything works fine again.

I have tried as many configurations as I can think of; Static, Dynamic, Normal Trunking. I have also tried setting the trunk up on different ports, all with the same result. Any Ideas? Thanks!

[Matt Hobbs]

What sort of trunking is configured on the Dell?

Not being familiar with the Dell switches at all, are you certain that their 'trunking' is the same as ProCurve trunking - i.e. port aggregation?

Trunking can either man VLAN tagging, or port aggregation depending on the vendor.

[Sam Fewster]

Hi, thanks for the quick reply. The Dell switch is configured properly for port aggregation. The configuration is similar to IOS, using the "channel-group 1 auto" command. "show lacp" on the HP switch shows LACP enabled, and partner YES for both ports 49 and 50.

Here is a snapshot of my HP config. Port 50 is down as this is a quick fix for the problem:

interface 49
no lacp
exit
interface 50
disable
no lacp
exit
trunk 49-50 Trk1 LACP

Thanks

[João Pedro Cruz]

Hello Sam,

I crossed with your post and I have similar issue between HP 2650 and server.

Did you found the solution for your problem?

I also tried several settings without success...

Thanks.

[Ben Dehner]

I can't offer a solution, but I'll point out that Matt's question "What sort of trunking is configured on the Dell?" was not answered.

There are 3 protocols that I know of for port aggregation. The HP switches use LACP, which is an IEEE standard. The others are EtherChannel, which is a Cisco proprietary standard, and MultiLinkTrunk (MLT), which is a Nortel proprietary standard. If the Dell/Cisco switch is (behind the scenes) using EtherChannel and not LACP, then you are going to have problems. Something to investigate.