cisco 3750 LACP problem

[torledo]

Hi All

I have configured a 24 port 10/100/1000 cisco 3750 to use ports g1/0/1 through to g1/0/5 as a link aggregated channel-group using LACP. To all 5 those ports i have connected an apple xserve which supports 802.3ad/LACP.

All ports are up both on switch and on server, operating at 1000mbps full duplex. I can also ping to any other node on the same switch.

I'm having problems pinging from the xserve to any device on a different switch.

I have connected the 3750 to a a 3524XL stack through gigabit port 23 on the 3750 to any random 10/100 copper port on the stack - i am able to ping from any host on the 3750 to a windows server connected to the stack, but i can't ping that server from the xserve. Neither can i ping the ip of the link aggregated server from the switch itself - although i can ping all other nodes, and nodes on the same switch can ping the xserve. Basically i cannot ping any device from the xserve that is not on the same switch and i think LACP could be the problem.

pls pls can some one advise ??

 

[vipergg]

could be almost anything , it's hard to speculate without seeing the configs . The switches obviously aren't setup correctly if you can't ping from one point to another unless someone setup ACL's that would block ping . You have to look at the configs and make sure all your ports are in the vlan you think they are in . Verify addresses and masks and make sure the default gateways on the nics are pointed to the correct addresses .

 

[chieftan]

Are you certain that the 1000mbps speed is set to auto on the Server and switch?

If it is then the problem is there. You have stipulated that the secondary switch is only 10/100.

Try setting all to 100 mbps / full duplex - manually and see if that works.

Are they on the same VLAN?

If not then you will need 802.1q trunking enabled.

As has been said, showing the configs would help.

 

[chieftan]

As an add on, have you tried PAGP (Cisco)?

 

[vipergg]

Don't think he could use pagp as he is etherchanneling to a non cisco device .

 

[chieftan]

Vipergg is correct. If it is not Cisco proprietary then you have to use LACP for etherchanneling.

Are you 100% certain that both ends of the Etherchannel are identical? If they are not then it will not work.

Sometimes, if the speed and duplex are set to auto, this can cause a problem. Try manually setting the speed and duplexing of the link. Make sure both ends of the link are the same.

Please post the config from both ends of the link and we may be able to help more.