[svlug] Routing a public class C through a Linux router

Drew Bertola drew at drewb.com
Mon Jun 15 19:39:25 PDT 2015

Wow, been many years since I've posted to this list!

I came across a task I've never undertaken, and it has me confused. We 
have been assigned by APNIC a public class C (/24).  I'm wondering how 
to route it through our linux router to a stack of hosts our customers 
will be using.  As of yesterday, our upstream provider is advertising 
the IP block.  Now I have to route requests through our router to the 
underlying hosts.

We also have an upstream provided /27, but only use a single IP from 
that group.

The router has interfaces as follows...

eth0: external - connected to our upstream provider.
eth1: internal company - private 192.168 network gateway.
eth2: customer hosting - need the public class C to route through to 
boxes on this network.

My thought is that I need to assign the class C's a.b.c.1 IP to eth2.  
This will be the gateway.  Then add a route from eth0 to eth1 for the 
class C's /24.

Is this all that is required?

Best to all,

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