Etherchannel on PSeries slow

[Theoneandonly]

Hi all,

We recently moved our patch panel to Nortel switches (from hubs). Since them, 4 of our Pseries server (AIX 5.1) are slower than ever. The two NIC, for each servers, are connected to different switches. Server 1-NIC1 to switch 1 and Server1-NIC 2 to switch 2, and so on for the 4 machines. It may be seems a newbie question, but are there some special settings to respect when using etherchannel and switches ?

Thanks

 

[DSMARWAY]

hi ,
how fast are your switches ?
normally on switch port you set the speed for example 100MB full duplex , on the NIC on the sever you set the speed
smitty dev ( lsattr -El ent? ?=0,1,2etc.)

to check what the speed is type :-
entstat -d ent?
look fro media speed

if the port on the swithces don't match then you need to check which end , if the switch end , speak to the guys who look after the switch and change the speed.

You will also see the port speeds set to auto negotiate , doing an entstat will show you what speed the ports are set to / are running at.

if your NIC spped is different to activate you, you can reboot your server or bring the interface down and up .

 

[Theoneandonly]

All switch port are one autosense. All NIC on all servers are on 100_FULL_DUPLEX. Should I force switch ports to the same settings ?

thanks

 

[clund]

Yes ... autosense doesn't always work as advertised. Over the years I've seen that many times. So force the everything to the highest common denominator.

 

[unixfreak]

No, setting it on the server is fine:

chdev -l ent0 -a media_speed='100_Full_Duplex'

Cheers

 

[clund]

ummm ... bzzzzzzt ... wrong
Just two-three weeks ago we put in a new server and I had it set to 100Mb full duplex on the server. The switch (some cisco thing ... don't ask me what 'cause I'm not a network admin ) was set to auto-sense. And it certainly did not work as advertised ... I always try to remember to ask the network guys to make sure that the switches are forced to 100Mb when I put in a new box.

 

[Theoneandonly]

Thanks to all for you info. I forced the speed on port on the switch, and everything is fine now.