Re: [Users] Default route on hosts
Can users outside of the hosts' networks reach the VMs in the hosts?
If you use netstat -rn it is expected that the gateway will be 0.0.0.0, as ifcfg-ovirtmgmt
has DEFROUTE=yes and ifcfg-public has DEFROUTE=no, then ovirtmgmt's
'gateway' (0.0.0.0) will be determined as the host's default gateway. However
with the new multiple gateways feature we configure source routing to make
sure that traffic that comes (from the outside) in the public network's device will
return the way it came in.
You can use 'ip rule' to see the rules VDSM configures. It creates two rules and a
routing table per device. You can use 'ip route show table %s' on each
table, where the IDs can be obtained by 'ip rule'.
----- Original Message -----
From: "Chris Geddings" <chris.geddings(a)duke.edu>
To: "Assaf Muller" <amuller(a)redhat.com>
Sent: Tuesday, November 12, 2013 2:26:40 PM
Subject: Re: [Users] Default route on hosts
On Nov 12, 2013, at 3:32 AM, Assaf Muller <amuller(a)redhat.com> wrote:
oVirt 3.3 introduced a feature called multiple gateways which may
assist you. If you configured a gateway on the public network (Either statically via
oVirt
or via DHCP), then all traffic into the hosts through their public network NIC will be
returned via that nic, *even though* the host's default gateway is
ovirtmgmt's gateway.
So, interestingly or not, when I define a gateway on the public interface (through
the web management interface or DHCP), and I don't worry about making the
DEFROUTE=yes setting in my "public" network, the box behaves like it has an
incorrect default route. Now, my management network has a gateway
of 0.0.0.0, as it is a completely simple network, so that may be part of the problem.
I'm not sure the impact of a 0.0.0.0 as a gateway.
I'm not sure how to poke at this further to figure out where the breakage is. Routing
looks like it has gotten a little more complex, and I'm still operating with
'netstat -rn' and 'route add foo' type commands.
--Chris