Networking Question

[Peter Day_2]

Guys,
Recently I noticed that one of my server's was reporting what I consider to be excessive network collisions. This I picked up by using 'gpm', I have three questions

1. On on e system when I use 'glance' I can see Packets In, Out & Collision, but on the system in question, I see Packets In/Out and then the KB Rate..Why ??.

2. I have been informed that we may have to changed the LAN to turn off Auto Negotiate. How do you do this, and can it be doen on-line.

3. Is there another way of showing that we are getting these collision, but I need to be able to do this from the command line, and not GUI.

Thanks in advance,
Pete

[Steven E. Protter]

Might want to collect data with sar scripts(attached).

10/100 BaseT NIC's should not be auto negotiate, they should be hard coded speed and duplex, including the swtich settings, especially with Cisco switches.

Alternately, 1000 BasetT Giagbit lan's MUST be auto negotiate, straight through.

Check this. If you need to hard code those NIC settings its done in /etc/rc.config.d/hpbtlanconf

I can upload an example if you wish.

SEP

[Steven E. Protter]

attaching hpbtlanconf.

What kind of machine? What OS?

SEP

[Patrick Wallek]

1. Don't know

2. Use the lanadmin command. On a 100Mb card, you should definitely have AutoNeg turned off. To set the lan card with PPA 0 (use lanscan to find that out) to 100Mb with Full Duplex you would do 'lanadmin -S 100FD 0'

3. To see network interface statistics do a 'netstat -in'

For more information on any of the commands have a look at the man pages.

[Patrick Wallek]

Ah....Steven does bring up a good point. To make sure the settings stay in effect at the next reboot you will need to change the appropriate config file for your LAN card in /etc/rc.config.d directory.

The lanadmin command can be done while the machine is running with virtually no impact on users.

[Mark Grant]

Hi Pete!!

Are you still at Cazenove? If so how are they doing?

Anyway, the simplest way to see the number of collisions is "netstat -in" where you will find a "Coll" coumn for collisions.

I assume that you mean port and network setting. You find that often the server and the ports on the switches negotiate incorrectly, leaving your cards in half duplex mode. This makes it all go slowly. You should set the server to FULL DUPLEX and not worry about the port settings.

[Dave Hutton · Accepted solution]

You can also change the autonegotiate value in sam also. Which I'm sure is just doing the same command suggested above.

Dave

[Peter Day_2]

SEP,
In answer to your questions -

HPUX 11.00
Model K380

Pete

[Peter Day_2]

Mark,

No I 'left' Caz in Feb 03.

The netstat command is the command that I thought should display the info. But on this system, it doesn't.(see below)

Name Mtu Network Address Ipkts Opkts
lan2 1500 10.173.241.0 10.173.241.40 363754319 367772695
lo0 4136 127.0.0.0 127.0.0.1 14664 14664

As you can see there isn't a collision collumn.

Ahh !!

[Sridhar Bhaskarla]

Hi Pete,

1. Check the versions of glance you have on both the boxes and compare them.
2. If the speed of your lancard does not match that of your switch port, then you would see collisions. On HP, it is always suggested to turn-off auto negotiation. Also make sure the switch port is set to the same setting.

Find out the speed

#lanadmin -x

Ex., lanadmin -x 0 (for lan0)

On 11.0 and above CrdIn# - card instance number can be found with lanscan command. If lanX is your lan card, then X is your CrdIn# or ppa. You can change the settings by using the command


#lanadmin -X 100FD

Ex., lanadmin -x 100FD 0 (for lan0)

This will distrupt your network for 11 seconds or permanently if your switch settings do not match 100FD.

This will not survive next reboot. You will need to edit /etc/rc.config.d/hpconf file and hardcode the speed and duplex setttings where is the type of the card. For a gsc card, it would be hpgsc100conf. You can look at the file for syntax. Ignore the STATION Address there.

3. You can use lanadmin -g to display the stats.

lanadmin -g
For ex., lanadmin -g 0 |grep -i colli
for lan0.

-Sri

[rick jones]

I will respectfully disagree that 10/100 NICs on HP-UX systems shouldn't use autonegotiation. I myself have had considerable success with autoneg. Perhaps I'm charmed, or perhaps I've simply been blessed with good switches.

The KB/sec rate stuff in glance is something that comes in "newer" versions of glance so the suggestion to check your versions is a very good one.

If your NIC has been hardcoded to half-duplex and it reports _late_ collisions, that suggests a duplex mismatch. If your NIC has been hardcoded to full-duplex, and reports FCS errors, that suggests a duplex mismatch. Those are simply "suggests" and not 100% confirms.