On Sep 2, 2010, at 11:11 AM, Nick Hilliard wrote:
On 02/09/2010 13:20, lorddoskias wrote:
I'm just curious - what is the largest OSPF core (in terms of
number of
routers) out there?
You don't expect anyone to actually admit to something like this? :-)
Of course I do -- 'tis much for your reputation to have wrangled a
poorly designed, ugly network under control than to have only worked
at places with smooth sailing.... I *don't* expect the owner /
designers of these to come forward, rather those who inherited a pile
of choss to share war stories... :-P
I worked on a network that had >350 routers in an (non-zero) area.
Now, ~350 routers in an area doesn't sound *that* impressive, but on
average these devices had 6 interfaces in OSPF, and many of these
links were of the form:
[router A]-- {GRE} --- [firewall]-- {GRE in IPSEC} -------
[Internet]------- {GRE in IPSEC} ---[firewall]---{GRE} --- [router B]
Routers A and B would form an OSPF adjacency. Much of this was an
overlay network (over the Internet) and so the firewalls would build
IPSec tunnels. Of course, said firewalls would not pass OSPF, so we
had to build GRE tunnels between routers A and D and run OSPF over
those -- traffic would enter the router, get encapsulated in GRE and
then the GRE would be encapsulated in IPSec and tossed into the void....
In other places (in the same OSPF area) we would purchase parallel
T1 / E1s that we would run MLPPP over, and / or plain DS3s.
Oh, did I mention that network was primarily to support international
call centers that had been outsourced to wherever was *really* cheap,
and that many places with very cheap labor have very poor
infrastructure? It was not uncommon to have interfaces that would
bounce 5 or 10 times a day*....
W
*: And yes, we did 'ave to get up out of shoebox at twelve o'clock at
night and lick road clean wit' tongue. We had two bits of cold gravel,
worked twenty-four hours a day at mill for sixpence every four years,
and when we got home our Dad would slice us in two wit' bread knife.
Nick
--
It's a mistake trying to cheer up camels. You might as well drop
meringues into a black hole. -- Terry Prachett
