Ethernet Collisions

[p-hogan]

What is the maximum acceptable level of collisions on an ethernet interface (running half dulpex) as a ratio of packets throughput?

[lgijssel]

Opnions on this matter will vary, depending on whom you ask.

I would say levels below 1% are acceptable. With a ligth load on a segment, this should be far less.

[p-hogan]

Is this as a percentage of input or output packets - or either?

[a.manosca]

Here are some info:

Collisions are a normal part of Ethernet CSMA/CD.

Collisions are a way to distribute the traffic load over time by arbitrating access to the shared medium. Collisions are not bad; they are essential to correct Ethernet operation.

Based on the Cisco Internetwork Troubleshooting (CIT) Vol. 1 manual,

the total number of collisions with respect to the total number of

output packets should be about 0.1% or less.

A packet that collides is counted only once in output packets.

Hope this helps.

[Tsasbrink]

This is abslotly true, the only thing i can ad is that the earlyer mentioned 1% is the vallue of collisions where users can see performance degradtion.