Is AIX etherchannel compatible with Nortel MLT

[Theoneandonly]

Hi all,

I've 4 Pseries (610 and 630) connected to Nortel Switches BPS 2000. Since the beginning, I've had really bad speed, wether on applicative level, telnet, ftp, even ping. Etherchannel on AIX 5.3 TL4 SP1 is set to 100Mbps_full duplex. I wanted to create trunking on the Switch level on the two servers NIC ports, but speed does not change. FTP stays at 39KB max for example. If I force 100 on the two ports, it's ok, I get my 10MBps. If I set back to auto-negociate, its brought back to 39KB and 100 half (indicated only on Switch port, no on AIX level). I don't know wether it's etherchannel config (you don't really have much choices to set) or Switch collisions (or else) which is the problem.

Has anyone tried to do the same to improve speed ?

Thanks for any info

 

[khalidaaa]

I never tried to use etherchannel to speed up the link speed but i can say that you have to first identify the physical link speed of your network (like 10/100 or Gigabit network) and then try to set the AIX ethernet channel and the switch ports to agree on one link speed! for example if you set the switch to use 10/100 then you have to configure the AIX ethernet to be 10/100 as well! IMHO, Don't use the auto-negociate coz it will try to use the least agreed speed between the switch and the aix box.

Regards,
Khalid

 

[Theoneandonly]

Thank Khalid,

Etherchannel has not been set on our server so much for the speed than for failover. But what's bothering me is that our network is 100, as transfer rates show me when I force it, but everytime I set back to autoneg, it goes down to more or less 300Kpbs/sec...moreover, It's trunked, so it should be 2X10MB, or I'm missing something.

Regards

Dave

 

[khalidaaa]

well, I don't know much about trunking to be honest but i got this while googling:

Network trunking is a technique to increase communication bandwidth by connecting multiple ethernet NICs(especially 100Base/T Ethernet). To realize network trunking communication, multiple ethernet NICs on one PC and ethernet switches for the ethernet NICs are needed, and PM/Ethernet configuration files for each ethernet NIC must be prepared and tested.

http://pccluster.org/faq/en/reference/pm/ether-trunking.html

So what you said is right about increasing the bandwidth. But again you have to set both the switch and the ethernet adapter to 100 as this is the bandwidth you are using on your network! and according to what i read over there, you would get 2x(your network speed) using trunking!

Regards,
Khalid

 

[foobar13]

You said switches (plural). You can't trunk across the switches. The best you can do is use the adapters in failover mode. I tried this on our p690s using a pair or Cisco 4507's and got pretty much the same results you did.

I found entstat to be helpful in diagnosing the problems.

 

[Theoneandonly]

I can trunk across Switches, if they are cascaded, which mine are. What do you mean failover ?

 

[mrn]

Have you set the switch ports to passive?

Mike

"Whenever I dwell for any length of time on my own shortcomings, they gradually begin to seem mild, harmless, rather engaging little things, not at all like the staring defects in other people's characters."

 

[Theoneandonly]

mrn,

yes I did.

 

[mrn]

Can you post the output from

entstat -d ent8 | egrep -i "Aggregation|Operating mode|Hardware|PVID|Device Type|ETHERNET STATISTICS"

where ent8 is your aggregation device



Mike

"Whenever I dwell for any length of time on my own shortcomings, they gradually begin to seem mild, harmless, rather engaging little things, not at all like the staring defects in other people's characters."

 

[Theoneandonly]

ETHERNET STATISTICS (ent2) :
Device Type: EtherChannel
Hardware Address: 00:09:6b:ab:02:f4
Operating mode: Standard mode
ETHERNET STATISTICS (ent0) :
Device Type: IBM 10/100 Mbps Ethernet PCI Adapter (23100020)
Hardware Address: 00:09:6b:ab:02:f4
ETHERNET STATISTICS (ent1) :
Device Type: IBM 10/100 Mbps Ethernet PCI Adapter (23100020)
Hardware Address: 00:09:6b:ab:02:f4

 

[mrn]

Can you try the following

smit chgethch

Change

mode to 8023ad
and hash mode to default

Mike

"Whenever I dwell for any length of time on my own shortcomings, they gradually begin to seem mild, harmless, rather engaging little things, not at all like the staring defects in other people's characters."

 

[Theoneandonly]

I'll have to try that later, as it's my production server, but thank anyway.

 

[foobar13]

I can trunk across Switches, if they are cascaded, which mine are. What do you mean failover ?

I mean that only one adapter is active at a time. AIX etherchannel can do this.

I didn't know that about cascading. Thanks for the tip.