I'm starting to use UML to test network situations, starting with
VRRP. I've noticed that shutting down a UML does not necessarily shut
down the host setup. For instance and to take a simple example, if uml2
is used with two network interfaces to route packets from uml1 to uml3
it works fine. But then, if uml2 is shut down, the routing is still
taking place even though the router has disappeared. Same if uml2's
eth0 and eth1 are brought down. The routing continues when it
shoudln't becuase uml2 is the router between uml1 (10.0.0.0/24) and
To really shut down the routing after the uml router is gone, the
host setup has to be modified. Deleteing the routes for the umls for
So I'm certainly missing something there and I'm not doing it right.
Is there a way to test networking situations with umls without having
to modify the host's networking setup to simulate umls routers appearing
and disappearing ? I mean, isn't this supposed to be taken care of
transparently by the umls (eg. the commands automatically sent to the
host when configuring an eth0 link for instance) ? Shoudln't the
appropriate commands also be sent transparently to the host to reflect
the bringing down of a uml eth interface ?
Thanks for any pointers and suggestions.