Gigabit Linux Routers

Florian Weimer fweimer at
Wed Dec 17 15:23:44 UTC 2008

* Eugeniu Patrascu:

> You can also use a kernel with LC-Trie as route hashing algorithm to
> improve FIB lookups.

Do you know if it's possible to switch of the route cache?  Based on
my past experience, it was a major source of routing performance
dependency on traffic patterns (it's basically flow-based forwarding).

Anyway, with very few flows, we get quite decent performance (several
hundred megabits five-minute peak, and we haven't bothered tuning
yet), running on mid-range single-socket server boards and Intel NICs
(PCI-X, this is all 2006 hardware).  We use a router-on-a-stick
configuration with VLAN separation between all hosts to get a decent
number of ports.

My concern with PC routing (in the WAN area) is a lack of WAN NICs
with properly maintained kernel drivers.

Florian Weimer                <fweimer at>
BFK edv-consulting GmbH
Kriegsstraße 100              tel: +49-721-96201-1
D-76133 Karlsruhe             fax: +49-721-96201-99

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