Serving Multiple Subnets on one NIC, and two vNICs

[Vladimir-M. Obelic]

Hi,

I did similar setups. Not sure how your topology looks like but one
way is to use VLANs and a L2 switch. You need to use VLANs for your
subnets 26&37. Even QinQ is possible...
Get familiar with ip link commands to assign certain VLAN tags for
your two subinterfaces.
After that its just like you presumably already configured the dhcp server.

Regards,
Vladimir

On 1. 8. 2012., at 10:43, Adam Wolfe <kadamwolfe at gmail.com> wrote:

> I am in the middle of setting up a new dhcp server between 3 subnets, using ubuntu 10.04.
>
> The subnet that eth0 is connected to is 10.8.35.0 and will not use dhcp at all.
>
> The subnet that eth0:26 is connected to is 10.8.26.0, eth0:37 is on 10.8.37.0
>
> I see dhcp discover, request, ack and offer all happening in /var/log/syslog, but the client never picks up an address.  It simply sits there doing it's dhcp discover.  I'm fairly certain this has to do with the routing as I am able to ping the address on eth0, but not eth0:1 eth0:2
>
> My routing table is:
>
> Kernel IP routing table
> Destination     Gateway        Genmask         Flags   MSS Window irtt Iface
> 10.8.37.0       0.0.0.0         255.255.255.0     U         0 0          0 eth0
> 10.8.35.0       0.0.0.0         255.255.255.0     U         0 0          0 eth0
> 10.8..26.0      0.0.0.0         255.255.255.0     U         0 0          0 eth0
> 0.0.0.0         10.8.37.1      0.0.0.0               UG        0 0          0 eth0
> 0.0.0.0         10.8.26.1       0.0.0.0               UG        0 0          0 eth0
> 0.0.0.0         10.8.35.1       0.0.0.0               UG        0 0          0 eth0
>
> Does anyone have some experience or expertise on what routes should be in place?  I'm practically positive on my dhcp.conf, it was copied from another, already working, server.  It just seems like it doesn't know where it should be sending the info to, but it is trying.  It also cannot ping other devices on the 26 and 37 subnets.
>
>
> I was also wondering how to overcome the 'not configured to listen on any interfaces' caused by adding "INTERFACES="eth0 eth0:26 eth0:37" " to /etc/default/dhcp-server.  I don't necessarily need this option added, but it might be nice for future growth to eliminate chatter.
>
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