[nsp] Cisco 3620 - Border Router
Todd, Douglas M.
DTODD@PARTNERS.ORG
Tue, 27 Aug 2002 10:22:43 -0400
Giuliano:
EEaks.... if this is your processor with only the ATM and other interfaces
then I would recommend that you look to upgrade your router to maybe a 3660
or 7200. Cisco has some great trade-in deals... One thing with a 3660 is
that you can reuse your cards you have in the 3620. However, you can not
do this with a 7200. The memory on the 3620 is NA on a 3660 so you will
have to upgrade that when you purchase the router.
Yes you are correct with the ospf calculations. It will have to make
adjustments for LSA's that are advertised by all the areas the device has
links in. However, if designed carefully with the use of NSSA, STUB,
Summarization at all possible points you can dampen link flaps and thus
reduce the number of calculations that are needed. There are timers that
OSPF does have that allow you to tune the database, however, care must be
given that you do not unoptimize your network redundancy when you are trying
to optimize CPU and limit lsas received.
==DMT>
> -----Original Message-----
> From: Giuliano Cardozo Medalha [mailto:giuliano@usp.br]
> Sent: Tuesday, August 27, 2002 6:49 AM
> To: Todd, Douglas M.
> Cc: cisco-nsp@puck.nether.net
> Subject: Re: [nsp] Cisco 3620 - Border Router
>
>
> Dear. Mr Tood,
>
> Thank you very much for you explanations.
>
> I am very worried about memory and CPU utilization for our equipment.
>
> Atached I sent you a picture with a MRTG graph for our 3620 CPU
> utilization actually.
>
> When I put this router making part of 5 ospf areas, it will
> participate
> on dijkstra calculus for all 5 areas ? It mean that it will
> have have t
> o make convergence calculus for 5 ospf areas ?
>
> Thank you again !!!
>
> Giuliano
>
> > Giuliano:
> >
> > Your question is if the 3620 will support the load of the
> whole ospf database?
> > Since we are breaking the network into different areas you
> will have the ability
> > to summarize where necessary and thus reducing the load on
> your router.
> >
> > 5 areas should not be a problem depending on the amount of
> memory this router is
> > running and it's current processor load. HOWEVER, To run
> ATM you must have
> > atleast 48Mbs of memory in the router and here you are
> mostlikely pushing the
> > box a little more than most people. Keeping an eye on your
> processor, buffers,
> > and memory you can make sure you don't kill your router
> with the addition of
> > these areas.
> >
> > Summarize as much as possible will help you in this process.
> >
> > ==DMT>
> >
> >
> >>-----Original Message-----
> >>From: Giuliano Cardozo Medalha [mailto:giuliano@usp.br]
> >>Sent: Tuesday, August 27, 2002 5:13 AM
> >>To: cisco-nsp@puck.nether.net
> >>Subject: [nsp] Cisco 3620 - Border Router
> >>
> >>
> >>Hi,
> >>
> >>I am in an OSPF project using cisco 3620 series with Fast
> >>Ethernet and
> >>ATM E3 interfaces (besides other devices) and I have some questions
> >>about performance.
> >>
> >>The following picture describes the topology:
> >>
> >>
> >> Public AS Public AS Public AS
> >> | | |
> >> 7000 7000 7000 14 x 2511
> >> A1 A2 A3 A4
> >> Campus 1 Campus 2 Campus 3 Campus 4
> >> () () () ()
> >> | | | |
> >> | | | |
> >> |_______|_________|____________| ATM / FR
> cloud - FRF8
> >> 0
> >> 0 ATM
> >> 0
> >> Cisco 3620
> >> 0
> >> 0 Fast Ethernet
> >> 0
> >> 0
> >> 0 BI 1 - A6
> >> Public AS <---###---------### -----### - Big Iron 2 A7
> >> Net Iron | \
> >> | \
> >> | \
> >> ### -----### - Big Iron 3 A8
> >> BI 4 A9
> >>
> >>
> >>The picture tries to explain the following environment:
> >>
> >>We have 5 major campi for a university. Campus 1 is bigger
> >>than others
> >>and has 6 devices: 4 foundry big iron, 1 foundry net iron
> and 1 cisco
> >>3620. The autonomous system of the entire university is
> >>private and the
> >>path to the public internet is made by the Public AS
> described above
> >>(Net Iron - running BGP4).
> >>All this 6 devices runs OSPF, creating the backbone area - Area 0
> >>Besides, each big iron has another area configured (A6, A7,
> >>A8 and A9).
> >>Each area has only one agregated group of IPv4 adresses that we can
> >>summarize.
> >>
> >>Cisco 3620 is used to connect all other 4 campi to the
> major campus.
> >>Each campus has its own network infraestructure and its own
> ospf area
> >>(A1, A2, A3 and A4) with another agregated group of IPv4 adresses.
> >>
> >>These campi are connected to the 3620 router by Frame Relay
> >>cloud with
> >>the FRF8 schema - (FR / ATM).
> >>
> >>Cisco 3620 has one ATM interface for an E3 link to provide
> access to
> >>these campi. Campus 1,2 and 3 has another path to the public
> >>internet by
> >>Nortel Shasta devices. The FR link is used only for backup.
> >>
> >>I would like to implement this architecture and need some
> >>help, because
> >>I really dont know if the 3620 router will supoort this
> >>amount of load -
> >>it is part of 5 ospf areas and still needs to work with 20
> >>PVCs ATM and
> >>1 Fast Ethernet
> >>
> >>Anybody could help me ?
> >>
> >>Thanks a lot
> >>
> >>Giuliano
> >>
> >>_______________________________________________
> >>cisco-nsp mailing list real_name)s@puck.nether.net
> >>http://puck.nether.net/mailman/listinfo/cisco-nsp
> >>archive at http://puck.nether.net/pipermail/cisco-nsp/
> >>
> >
> >
> >
>
>
> --
> Giuliano Cardozo Medalha
> Centro de Computação Eletrônica
> Universidade de São Paulo
> giuliano@usp.br
>