FreeBSD 10.2 , ospf vs. aggregated static routes, performance issue

[Alexander V. Chernikov]

25.08.2015, 17:46, "Julian Elischer" <julian at freebsd.org>:
> On 8/25/15 10:07 PM, Evgeny Khorokhorin wrote:
>>  Hi,
>>
>>  I have 10.2-STABLE, 2 CPU Intel E5-2643v3, network Intel XL710 with
>>  1.4.0 driver from Intel
>>  I know that going through routing table is very fast (rn_match). But
>>  I decided to optimize routing table.
>>  I'm using 2 interfaces - ixl0 and ixl1.
>>  Behind ixl0 I have 304 networks 172.16.. from /28 to /24 all via the
>>  same gw 1.1.1.1 (because ip on ixl0 with /30 mask). And behind ixl1
>>  I have default route via 2.2.2.2.
>>  That 304 172.16 networks I receive via OSPF (quagga). Now all is OK
>>  - on every interface I have up to 500kpps/395kpps, 4.5Gbps/1.57Gbps
>>  (rx/tx on ixl1 and tx/rx on ixl0).
>>  If I disable OSPF and in zebra add static route 172.16.0.0/12 via
>>  1.1.1.1, the system works good until traffic grow up to
>>  251kpps/181kpps , 2.27Gbps/637Mbps. After that the system is
>>  degrading: ixl's queue threads utilizes 100% CPU and I see many many
>>  traffic drops (netstat -i)
>>  If I turn on ospfd and receive 304 more specific routes the problem
>>  disappears.
>>
>>  Where is the problem? Or I have misunderstanding about how FreeBSD
>>  uses routing table..
>>  P.S. I use this machine as NAT. I checked this on ipfw and pf, all
>>  the same.
>
> without knowing anything, it looks like a lock on the route is a
> bottleneck.
> lots of routes spreads the pain..
Julian is absolutely right - there is currently a contention on individual route entries,
so I'd better leave ospf (and keep static route so speed of ospf convergence won't hurt).
Or if you want to totally get rid of dynamic protos, than yes, you will have to split this static
route into smaller pieces to reduce contention..
>
> try two manually added static routes 172.16.0.0/13 and 172.24.0.0/13
> (I hope I split that correctly) and see if it changes things..
> then try 4..
>
>>  -- Cheers,
>>  Evgeny
>>
>>  _______________________________________________
>>  freebsd-net at freebsd.org mailing list
>>  https://lists.freebsd.org/mailman/listinfo/freebsd-net
>>  To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>
> _______________________________________________
> freebsd-net at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-net
> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"