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Subject: Re: netmap, selective processing.
References: <ygfzjg9tcs5.fsf@corbe.net>
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On 16.07.2014 19:48, Daniel Corbe wrote:>
> I hope this it the right place to ask questions about netmap.  I'm
> toying with the idea of writing a netmap-based OSPF implementation
> because bird's OSPF implementation isn't as good as its BGP
> implementation, quagga doesn't scale well and openospfd doesn't compile
> on 10-RELEASE or CURRENT.

How many prefixes do you have in your OSPF area 0? If you run into
scalability problems with OSPF on current x86 CPUs your network design
probably is the cause of the problem e.g. redistributing announcements
from BGP into OSPF.

OSPF is just one more (rather ugly) IP protocol. Is moving the OSPF
packets between kernel and userspace really a problem worth optimizing
for? Putting netmap between the NIC and the kernel IP stack introduces
overhead to all non OSPF packets unless your netmap application also
implements IP routing and bypasses the kernel.