Thanks Peter.
I have browsed through Howards's BGP series, but for me, sometimes too long
explanations are more frustrating than a 10 words fact.
Two additional questions if you don't mind, and you have a minute or two :-)
1)
If you only have one BGP connection to one remote AS, IBGP would normally
never be used, and you would in most cases create a static default route to
the BGP router and redistribute it in your IGP. Am I right?
2)
Should you have multiple BGP routers in the AS connected to two different
remote AS's - would I always configure IBGP between them, or would there be
situations where IBGP would still be unused?
Thanks again,
Ole
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ole Drews Jensen
Systems Network Manager
CCNA, MCSE, MCP+I
RWR Enterprises, Inc.
[EMAIL PROTECTED]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
http://www.RouterChief.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NEED A JOB ???
http://www.oledrews.com/job
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----Original Message-----
From: Peter Van Oene [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, August 08, 2001 2:38 PM
To: Ole Drews Jensen; [EMAIL PROTECTED]
Subject: Re: BGP: IBGP usage/clarification [7:15333]
A couple quick notes. However I would suggest if you have a subscription
that you step through Howards BGP series at www.certificationzone.com as it
might help you solidify your understanding.
First off, IBGP is not an IGP. If you want to get from point A to point B
in AS C, IBGP isn't your friend (unless operator X tweaked IBGP with lots of
messiness -ie NHS everywhere etc....) IBGP facilitates inter-AS routing by
enabling reachability information to be maintained within AS's. IGP are
still required to enable routing within the AS (ie intra-AS routing).
IBGP is used when you have multiple BGP routers in an AS. Really not much
more to it than that at a high level. Whether or not you chose to use a
dynamic IGP versus a static configuration really is up to the administrator
with typical pros/cons applying. I have seen some cases where stub AS's
(those not providing transit) may have border routers communicating via BGP
to ISP's without peering amongst themselves but these are pretty unique
(weird) situations which often beg the question why BGP in the first place,
but this would be an fruitless digression.
Pete
*********** REPLY SEPARATOR ***********
On 8/8/2001 at 3:06 PM Ole Drews Jensen wrote:
>This might sound like a stupid question, but I have now read and
>practised a
>lot of BGP stuff, but there's one thing I am not 100% sure I understand;
>None of the books have been able to put the last brick in place in the
>puzzle for me.
>
>In what situations will "end-user" companies use IBGP and not just an IGP
>as
>OSPF or EIGRP?
>
>I believe that most ISP's use IBGP with a full mess where there are more
>than one EBGP connection - right?
>
>And a question to those of you who do a lot of BGP setup's for customers,
>how often do you typically use BGP at "end-user" companies and how often
>will IBGP be used there with or without an IGR running on their network(s)?
>
>Thanks for any comments on this,
>
>Ole
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Ole Drews Jensen
> Systems Network Manager
> CCNA, MCSE, MCP+I
> RWR Enterprises, Inc.
> [EMAIL PROTECTED]
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> http://www.RouterChief.com
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> NEED A JOB ???
> http://www.oledrews.com/job
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=15345&t=15333
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