Strange speed problem with 6200yl to 3Ccom4228

[BGergely]

Hi

One of our customer decided to change it's agregator switch (3Com4900SX -12p) to a 6200yl. (10-SX+14-1000B-T)
They own a lot of other 3Com switches (3300, 4500, 4200), that thay will migrate in time to HP.
But now after the midle switch change (star topology, with the 6200 in the middle), they have a very strage speed problem.
All other switches are linked to the middle with optical links. (becouse of the distance) All are working correcly except two 4228g. If you sit at one of the computers that are plugged in these you can copy up to the fileserver (plugged in tho the 6200 with 1g) in no time (good speed 30-40 mb/s), but you have terrible down speed (100-130k !!!!!!) On other switches there is no problem (up/down 30-40 Mb!!) (and when the old switch was in the midle [4900sx] there was no problen either!)
I cheched the links (1g..), checked the cables, checked the setting (no special things set..), tried to update the HP and 3Com firmwares (now all up to date).. no luck, the problen still there!

Has anyone any idea what can be wrong??

Best regards
B.Gergely

[Mohieddin Kharnoub]

Hi

I had a pretty similar issue with 5400 and Foundry switch, i was linking with fiber Multimode fiber and using the SX Mini-GBIC J4858B, and after i got my J4858B replaced with J4858C (the new version), and it worked fine.

Good Luck !!!

[BGergely]

Update

We tried to bring one of the switches "near" to the 6200 so we could link them together with 1000B-T (4228g has 2 1000b-t ports)
The result was dissapointing!! Same problem (up speed 30-40Mb/s, down 100k!!)

Becouse of that result, i don't think that the mGbic change will help. :o(

(Thanks for the tip!)

[Mohieddin Kharnoub]

Hi

I also had a similar situation, and the problem was if you download from one subnet to another one it will very fast, but not the other way.

And we found that their IDM was misconfigured with a policy that throttles the upload not the download.

I would like to ask,
are you doing routing on the 6200? if not the 6200, then who is doing routing ?
Are you trying to do that copy from one subnet to another one ?
Did you try to do the same from one subnet to another one?
Can you attach the configuration of your 6200 switch ?

Good Luck !!!

[BGergely]

Hi..

The affected switches, clients and servers are in the same subnet. (at the moment) No routing is done by any of the devices. (ISA2004 is doing it at the edge with a site-to-site vpn)
I could give you the conf. of the 6200yl, but you wouldn't see a thing becouse except of flow-control, and spanning-tree nothing is set. (flow-contol, and spanning-tree is set on the 3Com switches too.)

BGergely

[BGergely]

Update v2

After hours of trying recable, and reset, and reconfigure the devices without any change, we tried the following.. plugged the server to the 3Com4228 1000B-T port and a client to one of the 100B-T.. The problem still there!!! So.. the 3Com switch fa*****!!
I allready spoke one of the 3Com support engenieer, and they known about the problem! 4200 firmware earlier than 2.2 is bad!! (we have 3.04 :o( .. but they sad make it to 3.00 becouse it is the good one)

Update will follow ...

BGergely

[BGergely]

Update v3 (solution)

I talked with the 3com engeneer again, and the told me to change the 4228 QoS settings.
Head-Of-Line configuration had to be set to >Data<
Now everithing is working fine!! :o)

B.Gergely

[BGergely]

3com 4228g QoS Head-Of-Line configuration have to be set to >Data<

B.Gergely