Network fails after uninstall of kvm,xen and bridge-utils

**cop2** · September 30th, 2014

I am running Ubuntu server 14.04 (and therefore no package network-manager). I am not able to access the LAN after uninstalling kvm, xen and bridge-utils. There are no bridge interfaces remaining.

My interfaces files looks like

Code:

auto lo
iface lo inet loopback

auto em1
iface em1 inet static
address 172.16.40.34
netmask 255.255.255.0
gateway 172.16.40.1

netstat -rn gives

Code:

Kernet IP routing table
Destination          Gateway            Genmask              Flags             MSS  Window     irtt    Iface
0.0.0.0             172.16.40.1          0.0.0.0                   UG                  0      0              0      em1
172.16.40.0      0.0.0.0                255.255.255.0          U                    0      0              0      em1

lshw -class network shows that the Ethernet interface logical name is em1

ifconfig shows em1 interface with the correct ip address as in the interfaces file.

This was working before so I wonder what's wrong now. I am suspecting the bridge configurations done before are the culprits. Kindly assist as I do not wish to reinstall the OS.

**Doug S** · September 30th, 2014

Originally Posted by cop2

I am not able to access the LAN after uninstalling kvm, xen and bridge-utils. There are no bridge interfaces remaining.

Edit: I completely misread your post. I read "installing" instead of "uninstalling" above. Therefore my original reply, now deleted, was not what you wanted at all. Sorry.

Edit 2: Deleted my original, not relevant, reply and now:

Do you still have files like so:

Code:

doug@s15:/etc/libvirt/qemu$ ls -l /proc/sys/net/bridge
total 0
-rw-r--r-- 1 root root 0 Sep 30 08:48 bridge-nf-call-arptables
-rw-r--r-- 1 root root 0 Sep 30 08:48 bridge-nf-call-ip6tables
-rw-r--r-- 1 root root 0 Sep 30 08:48 bridge-nf-call-iptables
-rw-r--r-- 1 root root 0 Sep 30 08:48 bridge-nf-filter-pppoe-tagged
-rw-r--r-- 1 root root 0 Sep 30 08:48 bridge-nf-filter-vlan-tagged
-rw-r--r-- 1 root root 0 Sep 30 08:48 bridge-nf-pass-vlan-input-dev

If yes, then what are the contents?

Code:

doug@s15:/etc/libvirt/qemu$ cat /proc/sys/net/bridge/*
1
1
1
0
0
0

You could try to put "0" into each spot that has a "1". see also.
I wonder if you might need to specifically delete the bridge via re-installing the bridge utilities and running the "brctl delbr" command.

**cop2** · October 1st, 2014

Thanks for the response.
The directory

Code:

root@beantest:/etc# ls /etc/libvirt/qemu 
centos.xml    networks

There is no directory /proc/sys/net/bridge

Contents of net are

Code:

root@beantest:/proc/sys/net# ls 
core ipv4 ipv6 netfilter unix

Am now working on re-installing the bridge utilities and will get back. Thanks

**cop2** · October 1st, 2014

Since I could not get the bridge utilities to install (no network therefore no internet connection) I tried the commands below, rebooted and now the network works.

Code:

root@brucetest:/# ethtool -i em1  #To get the module being used for network under driver:
root@brucetest:/# modprobe -r e1000e  #removes the module
root@brucetest:/# modprobe e1000e  #reloads the module
root@brucetest:/# reboot