"late collision error" on Cisco Router 800 series

[nguyenxuanhoa]

Hi everybody,

My Router have one interface vlan1 connect to internal network, the other interface fe4 connect to ISP (Wan connection - fiber optics)

I have "late collision error" on fe4 when use show interface fe4 command, but no collision when I detect on vlan1.

The question is: can the problem be in our internal network or only because of WAN connection??? And anyone know the solution for it, i'm just thinking of duplex mismatch in WAN but can do nothing because cannot access ISP's side.

Thanks for your help,

[michaelmoty]

Nguyen,

6 years later, your solution just helped. 

Thank you very much for your help..