Bug 2896

Summary:	removing eth cable kills networking until cold boot
Product:	[Retired] Red Hat Linux	Reporter:	karrde
Component:	telnet	Assignee:	Jay Turner <jturner>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	medium
Version:	6.0	CC:	srevivo
Target Milestone:	---
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	1999-05-18 14:34:47 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description karrde 1999-05-17 23:55:41 UTC

I was changing out the ethernet cable on a running 6.0
machine (upgraded from 5.2) and when the new cable was in
(very fast switch), I had no traffic across eth0. ifconfig
looked fine and was up. Lights on the nic and the hub, no
traffic lights. ifconfiged eth0 down and up, no go. Did a
'reboot' and it still was not passing traffic across the
port. Did a 'shutdown -h now', then brought it up and was
fine and passing traffic again.

Comment 1 Jeff Johnson 1999-05-18 14:34:59 UTC

This sounds like a hardware problem.

Comment 2 Adam Thompson 1999-05-19 22:30:59 UTC

Some (poorly designed, IMHO) cards do this.  It is almost certainly a
hardware issue.  Possible workaround: rmmod followed by insmod.

Generally, forcing the driver to reinitialize the card will solve
this, but there are some *really* bad cards out there.

The chipset issue is usually something like:
- cable removed
- chipset detects no ethernet carrier; automatically tries to
renegotiate 10/100/HD/FD/whatever/TP/coax/ whatever it does;
- fails to find an ethernet connection; locks into some default mode
that may not be supported.  Default mode is often 10b2 or 10b5 (coax
and AUI, respectively) -- but most cards don't have these physical
ports.