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Posted to users@cloudstack.apache.org by Tim Mackey <tm...@gmail.com> on 2015/07/15 21:54:06 UTC
Missing guest default gateway
I feel this is something I should just know, but it's escaping me. For
some reason the virtual router for a guest network I've defined isn't
setting the default gateway via DHCP. This is CloudStack 4.4 with
XenServer 6.2 and it's an isolated network.
This is what ip route shows after restart:
[root@piwigo122 ~]# ip route
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.131
169.254.0.0/16 dev eth0 scope link metric 1002
If I add the default route in via "ip route add default via 192.168.1.1"
everything now works as expected.
The network was created using the
"DefaultIsolatedNetworkOfferingWithSourceNatService".
I do have egress rules in place, so it's only the lack of default route
which is causing me a problem.
-tim
Re: Missing guest default gateway
Posted by Tim Mackey <tm...@gmail.com>.
In case anyone runs into such a scenario in the future, here's what this
turned out to be. In /etc/sysconfig/network the GATEWAY from the source VM
was still present. Removing that allowed DHCP to set the default route
properly.
-tim
On Wed, Jul 15, 2015 at 4:26 PM, Tim Mackey <tm...@gmail.com> wrote:
>
>
> On Wed, Jul 15, 2015 at 4:14 PM, Erik Weber <te...@gmail.com> wrote:
>
>> On Wed, Jul 15, 2015 at 9:54 PM, Tim Mackey <tm...@gmail.com> wrote:
>>
>> > I feel this is something I should just know, but it's escaping me. For
>> > some reason the virtual router for a guest network I've defined isn't
>> > setting the default gateway via DHCP. This is CloudStack 4.4 with
>> > XenServer 6.2 and it's an isolated network.
>> >
>> > This is what ip route shows after restart:
>> > [root@piwigo122 ~]# ip route
>> > 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.131
>> > 169.254.0.0/16 dev eth0 scope link metric 1002
>> >
>> > If I add the default route in via "ip route add default via 192.168.1.1"
>> > everything now works as expected.
>> >
>> > The network was created using the
>> > "DefaultIsolatedNetworkOfferingWithSourceNatService".
>> >
>> > I do have egress rules in place, so it's only the lack of default route
>> > which is causing me a problem.
>> >
>>
>>
>> You wouldn't happen to have changed nics on the vm after deployment? Ie.
>> deployed with "network1", realized it was wrong, added "network2", sat
>> "network2" detfault, removed "network1"?
>>
> Nothing like that happened. It's a newly created instance with a single
> NIC.
>
>>
>> In those scenarios I have seen that the rules on the VR for not sending
>> default gw on the additional nic is not cleared after it has been set as
>> default.
>>
>> In that case, clear it manually (/etc/dhcphosts.txt, /etc/dhcpopts.txt or
>> something like that on the VR), or recreate the VR.
>>
> I do see an entry in dhcphosts.txt, but don't know what it should look
> like to know if it's broken.
>
>>
>> If that is not the case I don't know what's wrong, you could possibly
>> tcpdump the dhcp traffic on the vm to see if it receive the information.
>> That way atleast you can narrow down to troubleshooting either the VM or
>> the VR.
>>
> Since this is a template from a running system, I'll start with the VM
> tomorrow. Could very easily be cruft in there.
>
> Thanks
>
>>
>> --
>> Erik
>>
>
>
Re: Missing guest default gateway
Posted by Tim Mackey <tm...@gmail.com>.
On Wed, Jul 15, 2015 at 4:14 PM, Erik Weber <te...@gmail.com> wrote:
> On Wed, Jul 15, 2015 at 9:54 PM, Tim Mackey <tm...@gmail.com> wrote:
>
> > I feel this is something I should just know, but it's escaping me. For
> > some reason the virtual router for a guest network I've defined isn't
> > setting the default gateway via DHCP. This is CloudStack 4.4 with
> > XenServer 6.2 and it's an isolated network.
> >
> > This is what ip route shows after restart:
> > [root@piwigo122 ~]# ip route
> > 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.131
> > 169.254.0.0/16 dev eth0 scope link metric 1002
> >
> > If I add the default route in via "ip route add default via 192.168.1.1"
> > everything now works as expected.
> >
> > The network was created using the
> > "DefaultIsolatedNetworkOfferingWithSourceNatService".
> >
> > I do have egress rules in place, so it's only the lack of default route
> > which is causing me a problem.
> >
>
>
> You wouldn't happen to have changed nics on the vm after deployment? Ie.
> deployed with "network1", realized it was wrong, added "network2", sat
> "network2" detfault, removed "network1"?
>
Nothing like that happened. It's a newly created instance with a single
NIC.
>
> In those scenarios I have seen that the rules on the VR for not sending
> default gw on the additional nic is not cleared after it has been set as
> default.
>
> In that case, clear it manually (/etc/dhcphosts.txt, /etc/dhcpopts.txt or
> something like that on the VR), or recreate the VR.
>
I do see an entry in dhcphosts.txt, but don't know what it should look like
to know if it's broken.
>
> If that is not the case I don't know what's wrong, you could possibly
> tcpdump the dhcp traffic on the vm to see if it receive the information.
> That way atleast you can narrow down to troubleshooting either the VM or
> the VR.
>
Since this is a template from a running system, I'll start with the VM
tomorrow. Could very easily be cruft in there.
Thanks
>
> --
> Erik
>
Re: Missing guest default gateway
Posted by Erik Weber <te...@gmail.com>.
On Wed, Jul 15, 2015 at 9:54 PM, Tim Mackey <tm...@gmail.com> wrote:
> I feel this is something I should just know, but it's escaping me. For
> some reason the virtual router for a guest network I've defined isn't
> setting the default gateway via DHCP. This is CloudStack 4.4 with
> XenServer 6.2 and it's an isolated network.
>
> This is what ip route shows after restart:
> [root@piwigo122 ~]# ip route
> 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.131
> 169.254.0.0/16 dev eth0 scope link metric 1002
>
> If I add the default route in via "ip route add default via 192.168.1.1"
> everything now works as expected.
>
> The network was created using the
> "DefaultIsolatedNetworkOfferingWithSourceNatService".
>
> I do have egress rules in place, so it's only the lack of default route
> which is causing me a problem.
>
You wouldn't happen to have changed nics on the vm after deployment? Ie.
deployed with "network1", realized it was wrong, added "network2", sat
"network2" detfault, removed "network1"?
In those scenarios I have seen that the rules on the VR for not sending
default gw on the additional nic is not cleared after it has been set as
default.
In that case, clear it manually (/etc/dhcphosts.txt, /etc/dhcpopts.txt or
something like that on the VR), or recreate the VR.
If that is not the case I don't know what's wrong, you could possibly
tcpdump the dhcp traffic on the vm to see if it receive the information.
That way atleast you can narrow down to troubleshooting either the VM or
the VR.
--
Erik