[Xorp-users] difference with zebra

[Pavlin Radoslavov]

> So here it is, what is the difference of Xorp compared with Zebra in terms
> of routing (BGP,OSPF, ...)? I understand that Xorp in total is a superset
> of Zebra but I am only referring to the common parts.

Panos,

The answer depends on your needs. If all you need is, say, just
OSPF, then practically any solution that implements OSPF only
(e.g., http://www.ospf.org/) should work for you. If, however, you
are looking for a highly modular and extensible solution, then you
need a router that has much more flexible architecture.

For example, the XORP architecture allows you to run your router
components in a distributed fashion: e.g., the FEA (Forwarding
Engine Abstraction) on the machine with the forwarding plane, BGP on
another machine, and OSPF on a third machine. This could be very
valuable if you have CPU and/or memory limitations that could
prevent you from running all of them on a single machine.

If performance is not an issue, but you need a robust and easy way
to upgrade your router, then one thing you may want from your router
is the ability to hot-restart when upgrading each component
separately.
For example, if you want to upgrade a single component without
taking down the rest of the router, it is essential that there are
no API backward compatibility issues. The XORP architecture provides
a mechanism for supporting multiple APIs that is very flexible and
easy to use. Indeed, this is something that is invisible to the
users, but it is very beneficial for the developers. Therefore, this
could have a positive impact on the developers' ability to improve
the implementation and/or to add more features (which of course will
benefit the users as well).

For more information about the XORP architecture and its advantages,
you can read the following paper:
"XORP: An Open Platform for Network Research"
http://www.xorp.org/papers/xorp-hotnets.pdf

To be fair, if you need a routing solution now, currently XORP is
behind Zebra, so right now you don't have much choice.
Indeed, we are actively working on giving you that choice. However,
please bear in mind that the goal of the XORP project is not to give
you a Zebra replacement, but a platform that can be used for
research *and* in production environment. Though, early on it is
more likely that XORP would be used for network research, and when
it becomes stable enough it can be used in production environment as
well.

Regards,
Pavlin