BayStack 5510 MLT / Passport 8600 SMLT - no load balancing?

[atonns]

I have two baystack 5510s (v4.1.0.05) each with an MLT connected to two passport 8600s (3.7.4.0) configured for SMLT.

I have runs some tests using netperf from six Sun V210s (with 4 interfaces each) and I can't seem to get the traffic to loadbalance between the two links. I'm monitoring the links with SNMPv3 via the ifXTable MIB with a perl script / RRDTool - I can get 500Mb/s, but only on 1 uplink.

I have a case open with Nortel, I just wanted to poll the community here and see if someone else has seen this weirdness.

Thanks,
Tony

 

[PederChr]

I know there is some DMLT problem, with MAC adresses and MLT, can be the same problem as in CR Q0098954.

There wil also be a new software 4.1.1 i MAY (Nortel time) with fix on AUR ++

 

[xyCruiseryx]

Hi Atonns,

Have you configure a Port-Based-Smlt of the passports ??? Check the portconfiguration from SMLT-Ports (passsport) I know this problem because i forgot to disable the mirror status of the passports ports from a old configuration.

 

[atonns]

There's no port-based SMLT involved here. This is an initial implementation and I configured the Passports right out of the "SMLT Technical Configuration Guide" PDF. It is the K.I.S.S. case - plain old SMLT config, as I'm just trying to get a handle on things.

I'm wondering if it is this 'DMLT Problem' that PederChr mentioned. Can you explain more about it? I'm not sure how to view that CR number on the Nortel support site and search doesn't turn anything up.

 

[xyCruiseryx]

Hej antonns,

Notice: A standart SMLT is only working correct when you have a IST ( Inter Switch Trunk) between two devices.

A 5510 can not working with a IST.

Configure on 5510 a Port-MLT. The ports on the passport where the 5510 is working you must configure Port based SMLT. ( About Device Manager : Port - edit - smlt ) Here can you create a port based smlt)

look at:

http://www.ertlnetworks.de/pic.jpg

hope i can help you......

 

[atonns]

Notice: A standart SMLT is only working correct when you have a IST ( Inter Switch Trunk) between two devices.

A 5510 can not working with a IST.

Configure on 5510 a Port-MLT. The ports on the passport where the 5510 is working you must configure Port based SMLT. ( About Device Manager : Port - edit - smlt ) Here can you create a port based smlt)

Hm. I have an IST between my Passport switches. The two Baystacks are not connected to each other (ie: no 'cascade' as in your diagram) - they are only MLT'd to the Passport core. From what I understand, that should be a valid config. When I sent a copy of my configs to Nortel support, they confirmed they were valid and setup a test scenario in a lab. If you look at the "SMLT Technical Configuration Guide" - I have a standard 'triangle' setup.

I trust Nortel support will find a solution to my problem. I was just wondering if anyone else on this forum has seen a similar problem.

 

[xyCruiseryx]

Can you make a Lan Diagramm ???? I think the problem is not so hard ...

 

[atonns]

I don't have to... it's such a basic config, I'll use someone else's:

http://www.ldltech.com.cn/images/product/Nortel/BayStack380-24T-3.gif

Of course, instead of two BayStack380-24T, I'm using two Baystack 5510-48T. And everything is gigabit copper.

 

[xyCruiseryx]

OK,

have you configure the MLT on 5510 correct ???? Are the MLT enable on the device ???


by Passport: cinfigure on the Giga port : Edit - Smlt , here you you can configure a port based smlt. Do this on both passports ports where the 5510 is connect. Now it should working..

 

[Alainv]

How were the test systems configured.

In fact a (s)mlt or etherchannels are using the macaddresses or the layer 3 address to select the physical link it wants to use within the mlt.
Once selected then the whole conversation will stay on that same link.
If a mlt member fails, it will be recalculated again and it is quit possible that another link member will be selected.

The selection itself it a mathfunction. So if one station sends traffic to 1 other system, nortel chooses always the same link.