Interface Collisions

[monkp]

I have a 2600 router connected to a port on a 3550 switch. The ports on the switch and router are getting an extremely high number of collisions. The router is the only device on that port ...I have tried forcing both the router and switch port to 10 Meg half duplex, swapped ports on the switch and rplaced the ethernet cable (5ft).

What would cause collisions between 2 nodes?

[michael-faust]

Try forcing both the router and the switch to 100 / full.

What do you see now?

[scottmac]

Also, please post your IOS Revs.

Try 'em both at "auto."

Personally, I prefer to hard assign those kind of parameters, but for some reason, in some setups, you just have to go with the "Auto" feature or the systems will crank out collisions (and other errors).

Try a / some other jumper cables as well. A bad crimp or out of spec cable can also cause errors at high speeds (but work OK at slower speeds). If you have a purchased / commercial cable try that first.

Good Luck

Scott

[rjackson]

Collisons are normal, it s the CD part of CSMA/CD ethernet. Excess collisions are probably caused by broadcast traffic from another port. Track that host down by looking for high levels of input in the show interface command. If you go to full duplex the collisions will stop but the problem will still be there.