Ethernet collissions and errors for Catalyst 2924 and 3548 switches.

[DELL ACORD]

Can someone please help me with the matahamtical equations that I can use to determine the acceptable collisions and errors on the interfaces of IoS and CAToS switches. For example Collissions divided by packets in/out. Anything like that. All suggestions would be helpful.

Thanks,

DTA

[svermill]

Per the Designing Cisco Networks course:

No more than .1% of packets result in collisions.

MAC layer error rate = number of errors / total number of frames.

If you are having high number of collisions, check to see that all of your speed and duplex settings are entered manually. Autosetting = a bad thing.

[phampton]

Follow up question: How do you determine the correct duplex/speed settings for each port?

[svermill]

Everything on a port just needs to be consistent. If you have a router on the switch port, go with the highest possible speed and set both manually. Set for full duplex if possible. Same for anything else (server, workstation). Just keep it consistent and you should be OK.