Server with multiple public IP

[Andreas Nilsson]

On Mon, Apr 28, 2014 at 11:16 AM, Dominic Froud <dom at talk2dom.com> wrote:

> On 28/04/2014 09:58, Andrea Venturoli wrote:
>
>> I've got a server which has two (or more) interfaces with public IPs.
>>
>> Let's say, as an example (with fictional IPs):
>> ifconfig_vlan1="inet 1.0.0.2 netmask 255.255.255.248..."
>> ifconfig_vlan2="inet 2.0.0.2 netmask 255.255.255.248..."
>>
>> Of course, I can only have a default route, let's say 1.0.0.1.
>> This is fine for outgoing traffic and for incoming connections on vlan1.
>> However, when someone from the outside connects to 2.0.0.2, reply packets
>> still go out through 1.0.0.1 (on vlan1), but they should go through vlan2
>> to 2.0.0.1
>>
>
> You want source-based routing.
>
> I have this situation and I used pf(4) to do it with a rule like:
>
> pass out quick route-to ( vlan2 ) from 2.0.0.0/29 to any no state
>
> As a variation you can give an optional next-hop address if you have a
> static router for that vlan, e.g. if your router is 2.0.0.1:
>
> pass out quick route-to ( vlan2 2.0.0.1 ) from 2.0.0.0/29 to any no state
>
> Also, you can run pf and ipfw at the same time!
>
> Hope this helps,
>
> Dominic
>
>
You could put all the services which are on 2.0.0.2 in a separate fib and
there have another default-route.

Best regards
Andreas