I thought I was fairly careful in stating that with iBGP split-horizon, an
iBGP router will not advertise a route to the same AS from which it receives
the route. This covers the interface issue.
Chuck
whose mama didn't raise no fool, and whose lawyer wife has taught him the
hard way about wording things ;->
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Ole Drews Jensen
Sent: Tuesday, August 21, 2001 8:52 AM
To: [EMAIL PROTECTED]
Subject: RE: A new networking term - thoughts? [7:16668]
Chuck, I think there's a difference here. Split Horizon as you say, does not
advertise a route back out the interface that it received it on, but the
iBGP does not only not propagate a route learned from other iBGP out the
receiving interface, but it does not propagate it out any interfaces unless
it has been setup as a cluster server.
If you would name this, it would probably be something like "iBGP horizon"
:-)
Just my 00000010 cents.
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: Chuck Larrieu [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, August 21, 2001 10:29 AM
To: [EMAIL PROTECTED]
Subject: A new networking term - thoughts? [7:16668]
As a result of an off-list conversation, I came across the following
networking term:
iBGP split horizon
my first reaction was a sarcastic remark about never having come across the
term in the RFC's. but then I got to thinking about it, and I now see this
as a descriptive and quite useful term.
recall that distance vector protocols are subject to the rule of split
horizon. they do not advertise a route back out the interface that they
received that particular route.
one of the gotchas of iBGP is the fact that iBGP routers do not propagate
routes learned from one iBGP neighbor to other iBGP neighbors. hence the
requirement for iBGP full mesh.
so why not call this iBGP split horizon? and define it as follows: an iBGP
router will not advertise a route back out the same AS from which it learned
the route?
does this make sense? worth letting this one join the lexicon of networking
terminology?
Chuck
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=16757&t=16668
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
