ethernet help

[xeryus]

I have a 10/100/1000 ethernet card on my RS6000 and it is set to auto_negotiate. Currently it is attached to a 100 network backbone and I plan to attach it to a 1000 network backbone. While the system is up and running, I plan to unplug from the 100 and plug it into the 1000. Do I need to do something to the ethernet card for it to start using 1000 or will it automatically pick it up since it is set to auto_negotiate, once I plug it in?
Hope I made myself clear.
Thank you in advance.

 

[rzs0502]

When you unlug the 100 cable, your adapter will go down, and when the 1000 cable is plugged in, re-start the tcpip daemon.

I prefer to force the speed as on my network, I seem to get variances for some reason.

"If you always do what you've always done, you will always be where you've always been."

 

[DukeSSD]

I think the accepted wisdom is to force 10 and 10/100 adapters for both speed and duplex but to leave the 1000 adapters on auto negotiate.

 

[RMGBELGIUM]

Most of the gigabit adapters don't give you the option to set it to 1000 half or full, it's just giving you autoneg.

 

[sweetdaddyd]

Are you using Jumbo Frames on your Gig-E?
Also, you'll probably set the MTU and xmit queue size on your interface.

Here's the commands:
"ifconfig en0 detach" (assuming en0 is the interface you want to change. You must take down the interface in order to adjust the nic settings - make sure you're not telnet'd in on this interface.)

chdev -l ent0 -a media_speed=Auto_Negotiation -P
chdev -l ent0 -a jumbo_frames=yes -P **if applicable**
chdev -l ent0 -a tx_que_sz=16384 -P
chdev -l en0 -a mtu=9000 -P

check the settings with:
lsattr -El ent0
lsattr -El en0

Restart the interface
smitty tcpip
- or ifconfig