Discussion:
Routing table for BGP
(too old to reply)
devang patel
2008-05-16 14:16:07 UTC
Permalink
Hi,


I would like to know what route should i accept from internet full or
partial?
if Partial then what routes should i accept? and how many route does my
router have if i will go for Partial routing table?

actually I am trying to understand it by concept... my organization is small
but I want to know if it is large organization or small provider then what
kind of routes do i need in my routing table?

regards
Devang Patel
Joe Greco
2008-05-16 14:34:15 UTC
Permalink
Post by devang patel
Hi,
I would like to know what route should i accept from internet full or
partial?
if Partial then what routes should i accept? and how many route does my
router have if i will go for Partial routing table?
actually I am trying to understand it by concept... my organization is small
but I want to know if it is large organization or small provider then what
kind of routes do i need in my routing table?
If you don't know, then you should probably ask your upstream to send you
a default and leave it at that.

Full routes means that you get a routing entry for every network connected
to the Internet. There's some two hundred thousand (plus) of them. This
can be stressful on both routers and inexperienced administrators, and is
probably not all that useful unless you have multiple connections to the
Internet. A default gets you just about the same thing.

"Partial" doesn't make too much sense, unless you really don't want to
talk to certain parts of the Internet, or you're supplementing it with a
default route. You could potentially do this if you had, for example, a
T1 to two different providers, and wanted some outgoing traffic to go
over each link.

In that case, most people would prefer to get full tables from each
upstream and make local decisions. This requires properly resourcing
your router; the "Cidr Report" that is frequently posted here will give
you an idea about /current/ requirements in terms of table size, but it
is not unreasonable to look for something that can handle 30-50% growth,
plus IPv6 concerns.

If you've got an existing router that can't hack it, but still need to
balance over two connections, that's one scenario for "partial" routes.
By definition, partial would be any number between 1 and the current
number of available route prefixes, and would be determined by your choice
of configurations.

There are some really quite excellent books on routing on the Internet
available, as well as extensive information in this list's archive. Avi
also has some historical documents that are probably still good. Look
around

http://www.freedman.net/

... JG
--
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.
Roy
2008-05-16 14:43:32 UTC
Permalink
Post by devang patel
Hi,
I would like to know what route should i accept from internet full or
partial?
if Partial then what routes should i accept? and how many route does my
router have if i will go for Partial routing table?
actually I am trying to understand it by concept... my organization is small
but I want to know if it is large organization or small provider then what
kind of routes do i need in my routing table?
regards
Devang Patel
For small companies, I advise asking for "customer" routes. These are
people directly connected to the upstream. Other than that, the default
suffices.

Roy
Justin Sharp
2008-05-16 14:45:28 UTC
Permalink
Your questions depend on several details specific to your organization,
which you haven't really devulged.

There are several decent books on the subject which I recommend that you
invest in.
see: *
ISBN-10:* 0321127005
*ISBN-10:* 0596002548

http://www.oreilly.com/catalog/bgp/chapter/ch06.html -- this is a
chapter from the second book which should wet your appetite a bit.

Regards,
--Justin
Post by devang patel
Hi,
I would like to know what route should i accept from internet full or
partial?
if Partial then what routes should i accept? and how many route does my
router have if i will go for Partial routing table?
actually I am trying to understand it by concept... my organization is small
but I want to know if it is large organization or small provider then what
kind of routes do i need in my routing table?
regards
Devang Patel
_______________________________________________
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http://mailman.nanog.org/mailman/listinfo/nanog
Tuc at T-B-O-H
2008-05-16 14:59:15 UTC
Permalink
Post by devang patel
Hi,
I would like to know what route should i accept from internet full or
partial?
if Partial then what routes should i accept? and how many route does my
router have if i will go for Partial routing table?
actually I am trying to understand it by concept... my organization is small
but I want to know if it is large organization or small provider then what
kind of routes do i need in my routing table?
Hi,

If its only 1 provider, then probably taking just "default route"
is necessary. If you have 2, then it depends on your setup.

I prefer to always take full routes from upstreams, as long as there
are good communities within that feed. This way I can vary what I accept
or don't accept without the need to constantly contact the upstream. If
not, then I have to fiddle more on my end, but I always keep the control.

I personally run 2 routers (Ok, switches with routing code, so
my memory footprint is severely limited) each with a link to a provider.
I ask for full routes PLUS default route. Internally, I discard /24's on
both links, and pref up the communities like customer and send them over
to the other router with the default route. Saves me alot of memory, plus
gives me alot of control.

Tuc/TBOH
Barry Raveendran Greene
2008-05-16 15:00:52 UTC
Permalink
The nice thing about NANOG is that we have YEARS of on-line Video training
to help you get up to speed.

1. Go to http://www.nanog.org/subjects.html (Index of Talks)

2. Look for materials on BGP.

3. Have fun learning from the best.

My suggestion would be to watch last NANOG's BGP Tutorial. The nice thing
about this is that you can E-mail the speaker to get clarifications.

TO NANOG Community - We should really be pointed these FAQs to the
resources/tools we've invested in building. I don't know whose idea it was
to VOD everything, but it is an vast untapped store house of knowledge.
-----Original Message-----
Sent: Friday, May 16, 2008 7:16 AM
Subject: [NANOG] Routing table for BGP
Hi,
I would like to know what route should i accept from internet
full or partial?
if Partial then what routes should i accept? and how many
route does my router have if i will go for Partial routing table?
actually I am trying to understand it by concept... my
organization is small but I want to know if it is large
organization or small provider then what kind of routes do i
need in my routing table?
regards
Devang Patel
_______________________________________________
NANOG mailing list
http://mailman.nanog.org/mailman/listinfo/nanog
Christopher Morrow
2008-05-16 15:25:52 UTC
Permalink
On Fri, May 16, 2008 at 11:00 AM, Barry Raveendran Greene
Post by Barry Raveendran Greene
The nice thing about NANOG is that we have YEARS of on-line Video training
to help you get up to speed.
1. Go to http://www.nanog.org/subjects.html (Index of Talks)
2. Look for materials on BGP.
3. Have fun learning from the best.
My suggestion would be to watch last NANOG's BGP Tutorial. The nice thing
about this is that you can E-mail the speaker to get clarifications.
TO NANOG Community - We should really be pointed these FAQs to the
resources/tools we've invested in building. I don't know whose idea it was
to VOD everything, but it is an vast untapped store house of knowledge.
I think there is a nanog-wiki that Lynda was poking at last even??
Maybe making sure there's a searchable form thingy there for the VOD
catalog?

-Chris

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