> > I have one ethernet interface running on an Origin 200 Irix 6.4
> > Primary IP address is 184.108.40.206 /24
> > The alias on the interface is 192.168.100.2 /24
> > I need to set this machine up as a gateway between the two sub-nets. At
> > the moment whenever packets are sent from this machine, it sends out the
> > primary address as the source IP address. This is not helpfull.
> Depends on patches.
I'll have to explicit my response a bit, as many people have misunderstood
Whether routing between two subnets attached to the same interface works
using aliases depends on patches, but the original requesters of alias
functionality specifically *wanted* outgoing packets to use the primary IP
as source address.
This usually does not break the routing, as TCP/IP stacks of machines on the
`alias' network are usually prepared to accept non-RIP encapsulated packets
originating from any source, as long as the destination address is OK. We're
using it (both in the Brussels office and SGI at large), and many of our
customers use it.
But the source IP address is *always* the primary IP of the interface, and
in this respect aliases do *not* behave as `virtual interfaces'. We'll have
two conflicting sets of requests from customers, as some want the IP source
to be the primary interface address, and others apparently want the IP
source to be the alias, though I'm sure you could file an RFE requesting
that both behaviours be supported, of course ;).
This is even true in 6.5.
Alexis Cousein Added to confuse the enemy: