i386/68117: serious network collisions after NIC "media/mediaopt" change

[Suihong Liang]

>Number:         68117
>Category:       i386
>Synopsis:       serious network collisions after NIC "media/mediaopt" change
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Jun 19 19:00:33 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Suihong Liang
>Release:        5.2.1
>Organization:
University of Waterloo
>Environment:
FreeBSD hurricane.cs.uwaterloo.ca 5.2.1-RELEASE FreeBSD 5.2.1-RELEASE #1: Thu Jun 17 13:09:16 GMT 2004     root at hurricane.cs.uwaterloo.ca:/usr/src/sys/i386/compile/REAL  i386
>Description:
If the NIC's media/mediaopt is ever changed, then start a file transfer, there will be lots of network collision (~75%) reported by netstat. The collisions were also confirmed by the Netgear FS524 switch.

The NIC I have tried are: em0, rl0.

Note that same hardware configuration under Linux 2.6 works smoothly.
>How-To-Repeat:
ifconfig em0 media 10baseT/UTP mediaopt half-duplex (or full-duplex)

then scp a big file.
>Fix:
      
>Release-Note:
>Audit-Trail:
>Unformatted: