Re: [LARTC] Q: best solution to stop traffic to huge amount of

[Karl Gaissmaier <karl.gaissmaier@rz.uni-ulm.de>]

Robert Collier schrieb:
> 
> Hi Karl,
> 
> I don't have any suggestions for an easy way to solve your problem -
> but:
> 
> On Thu, Aug 22, 2002 at 09:38:58AM +0200, Karl Gaissmaier wrote:
> > With ip route I think I have to describe all unregistered hosts
> > to stop traffic and not the smaller amount of registered hosts.
> > Does the FIB and route cache scale well to approx 30k routes?
> 
> With 'large routing tables' enabled the kernel works just fine with a
> full internet routing table of 115,000 routes so a mere 30,000 should
> be a doddle.
> 
> Your main problem will be getting the routes into the kernel.

Yes this is a problem. I tried for fun to build a 64k routing table
with:
ip route add type prohibit 10.0.i.j
(i=0..255; j=0..255)
and this took more than one hour on my home desktop (old pentium 90)
to fill the routing table.
Even if I know that this is pretty old stuff I was astonished over this
slow progress.

The question that arises is now for me, how long does it take
for a full internet routing table to get synchronized after
a route flush with a linux router?

Anyway, you told me that the kernel works fine with 115k routes
but be aware I will use this with Gigabit Interfaces.

What is the average forwarding time in ms for a packet with
115k routes?

Best regards and thanks for your answer
	Charly

-- 
Karl Gaissmaier          Computing Center,University of Ulm,Germany
Email:karl.gaissmaier@rz.uni-ulm.de          Network Administration
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