NetworkManager hijacks LNST controlled interfaces

Radek Pazdera rpazdera at redhat.com
Mon Aug 6 10:23:50 UTC 2012


Hi,

there's a problem I've been dealing with network manager running on the 
slaves.

Each time a new interface is hot-plugged to the machine, NM creates a 
default
connection profile for it and executes it. It means, that it tries to 
run dhclient
on that interface once in a while.

That's a problem, because we configure interfaces on slaves "manually" 
with ip
command. This configuration is flushed when by NM when it tries to 
enforce the
"Auto eth5" default profile on the interface. There's not even a DHCP server
running in the environment I tested this in.

The thing is, that we need to have the network-manager running, because 
it starts
dhclient when the controller interface is plugged in. I don't know 
whether the
standard networking scripts can do this too. And if they can, we need a 
way to
turn NM off somehow anyway (which is hard, because we don't have shell 
at that
time yet).

NM has a D-Bus interface and a cli-wrapper around it called 'nmcli'. 
This utility
is shipped along with the NM package. It can be used to exclude some 
interfaces
from NM control by issuing

     nmcli dev disconnect iface eth2

command without necessity to restart the whole service (which is 
something we cannot
do, since we're connected through ssh).

Has this ever happened to you? It usually results a failure in the 
cleanup phase on

     ip addr del ...

command saying that it cannot clear the address (because NM already 
flushed it). Or
do you have NM off on slaves?

Radek :)


More information about the LNST-developers mailing list