no networking after replacing network card

[Michal Suchanek]

After replacing my network card (actually mounting the hardrive into a different system but the issue is the same) there is no networking anymore.

There is /etc/udev/rules.d/70-persistent-net.rules which lists the old MAC as eth0 and prevents the new card from becoming eth0.

There is /etc/network interfaces that lists all the eth intefaces generated so far (up to eth1) as "iface ethx inet dhcp".

However, the auto line only says "auto eth0 lo".

I am running Gutsy upgraded all the way from something really ancient.

Description: Ubuntu gutsy (development branch)
Release: 7.10

It looks like the system is not completely up to date yet so I will try to upgrade to the latest packages.

Scenarios that break this way and used to work before persistent net rules existed:

 - replacing your nic (or mainboard in case of onboard nic) when it dies or when you want a faster one
 - putting the hardrive into a different system or making a "mobile" installation on an USB stick or the like

[ispyisail (freesco)]

I've got the same problem!

I have changed my NIC and now the system can't detect eth0 etc

I assume you should be able to change cards without a system rebuild

[ispyisail (freesco)]

I solved the problem by deleting all entry's relating to older NIC in
/etc/udev/rules.d/70-persistent-net.rules

# PCI device 0x10b7:0x9050 (3c59x)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:60:97:2c:e8:f4", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

Then rebooting my machine

Then changing .........NAME="eth3" to ...........NAME="eth0" in
/etc/udev/rules.d/70-persistent-net.rules

for some reason it keeps counting up, eth5 eth6 etc

another thing i've noticed in Ubuntu 8.04 in /etc/network/interfaces
................................................
auto lo eth0 eth1
iface lo inet loopback

# The primary network interface
iface eth0 inet dhcp
..............................................

In the first line above you need to add "eth0 eth1"
in previous versions you only needed "auto lo"