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3750 port autonegotiation

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chazk1

Technical User
Sep 3, 2001
40
GB
Is there a problem with Intel EtherExpress PRO NICs and Autonegotiation settings using Cisco switches in general ?

I have 2 x Dell PowerEdge 6300's being used as Citrix servers.
If I set the NICs to Auto and likewise the same on the Cat 3750 core switch users report very slow response, likewise if settings are hard-coded to 100Mb/Full at both ends.

Setting the Server NICs to 100Mb/Half and setting the switch port speed at 100mb and duplex at Auto (cannot configure half-duplex) seems to offer best response.
 
Generally you should use the same setting at both ends (auto - auto, 100full - 100full, etc). If you can't set the switch to the same setting as the NIC, then they will default to 10/half.

Using the Ether Express NICs in a current server? These NICs are quite old, and I would look into Intel's current Pro Server Adapter line. However, there shouldn't be any problems. If you do a "show interface fastethernet0/0", do you see a bunch of errors?
 
Of course, if the negotiation fail, than the link is dropped to 10 Mbs + a bunch of errors.
If the NIC is old, so force it to 100 Mbs/half and the same for the 3750.

Hope this clarify.
 
Have forced both ends to 100 Mb/Half and still get errors.

Have moved from 3750 to 4003 and still getting errors.

sho port count 2/5

Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize
----- ---------- ---------- ---------- ---------- ---------
2/5 - 23080 0 46118 0

Port Single-Col Multi-Coll Late-Coll Excess-Col Carri-Sen Runts Giants
----- ---------- ---------- ---------- ---------- --------- --------- ---------
2/5 123251 74284 0 0 0 23038 0

Last-Time-Cleared
--------------------------
Tue Mar 16 2004, 07:13:49

As these servers are being made redundant very soon I won't bother the server guys to invest in time and money rectifying problem by upgrading NICs. Thanks anyway.
 
running in half-duplex will ALWAYS result in errors. It is do to the signaling detection. Try forcing both ends to 100 full duplex.
 
Thanks but have tried all possible combinations. It's strange but servers grind to (almost) a halt when both ends set to 100Mb/Full at both ends.

 
You have the latest drivers installed for this NIC? Maybe replace it with another NIC and do some more testing.
 
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