On Tue, Jan 16, 2001 at 10:25:37PM -0500, jamal wrote:
>
>
> On Tue, 16 Jan 2001, Gleb Natapov wrote:
>
> > Yes, zebra can handle multiple ifas, but ospf cannot. ospf can only
> > advertise
> > secondary ips as stab networks and cannot form adjacency through them, so
> > no transit
> > traffic. AFAIK CISCO does the same thing. The only way I see to handle
> > secondary
> > ips and be able to route transit traffic through them is to create virtual
> > interface
> > for each ip alias in zebra and feed them to ospf as real interfaces.
>
> You mean the ifa_label can be used as a interface name that zebra/ospf
> will understand? Ok, That should work + you might have to force sourcing of
> ip addresses given certain routes. I am not sure if zebra knows how to do
> that i.e can you tell zebra to set the route table such packets coming out
> of that link going towards certain destination will have the aliased IP as
> the source? It's easy to set on the command line, for example.
>
I am not talking about sending or receiving packets here. OSPF has a strong
notion
of interface. Interface has mtu, ip address and many OSPF specific parameters,
it has state that changes according to interface state machine, it has list of
neighbours,
etc, etc. All this things are needed in order to be able to build adjacency
through the
interface.
Currently zebra has one to one mapping between "kernel interfaces" and "zebra
interfaces".
If I want to run OSPF (I don't know about other protocols) on secondary ips
zebra should
be able to have "zebra interface" for each ip (and not for each interface), or,
in other words
one to many mapping. This is only theory, I don't know if it's even possible to
implement such
thing (you never know until you'll try ;)).
--
Gleb.
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