Alignment / FCS errors on BPS2000 1

[Max5Pier]

Hi,

I simply want to have a second opinion on informations givent to me by a (another) consultant...

We just installed a stack of pure BPS2000 switches connected to a Nortle router. Since its been up, I keep getting about 20-30 alignment and FCS errors a day from the switch on the router port. The consultant told me that its not abnormal. These errors could be caused by packets comming in in the wrong order, therefore creating errors.

Its sounds ok to me, but I still find it strange that two Nortel equipments still generate such an amount of errors, especially since Ethernet only normally allows a 1 in 100000000 bit error rate.

Can someone confirm this information ?

Thx

 

[jimbopalmer]

My normal issues with FCS errors are mis-setup ports, one is is hard coded full while the other is auto, or both ends are 100 but the wire won't do 100, that sort of thing.

if the Nortel router is hooked to T1/Cable/DSL so that the max thoughput is under 2 meg anyway, try setting the BOTH ports to 10/half. If it is good at 10/half, try 10/full, then 100/full, at both ends.

The ideal is 100/auto at both ends (I am assuming that is where you are now) but if conditions don't allow it, try the steps I listed til errors come back and backup one.

Super high speeds locally will not really help if this is a compative low speed remote route.

I tried to remain child-like, all I acheived was childish.

 

[Jynxx]

Things to check:

1.) Ensure that both the port on the switch, as well as the router port, are both forced...no auto-negotiation.
2.) Swap out the patch cable.
3.) Try a different port on the switch.
4.) Ensure that the cable is not running next to anything that could cause interference...ie flourescent lights, conduit, etc.

If you still get alignment and FCS errors after that, then it may very well be "normal"...as in you are never going to completely get rid of them. We have a few servers (out of several hundred) that connect to Passport 8600's, and they do the same thing. We have tried everything imaginable with no luck, su we just left it.

 

[Jynxx]

FYI 20-30 per day is not going to affect performance.

 

[Max5Pier]

Thanks for the tip.
I will do the tests you suggested...