Re: BGP Command: neighbor next-hop-unchanged

Hi,in the example below the unchanged cmd is applied towards router C (
eBGP), default behavior of ebgp is to change next-hop unlike iBGP. to reverse
default behavior in eBGP use next-hop-unchanged, to reverse it in iBGP use
next-hop-self.
thanks
--- On Mon, 8/3/09, Joe Astorino <jastorino_at_ipexpert.com> wrote:

From: Joe Astorino <jastorino_at_ipexpert.com>
Subject: Re: BGP Command: neighbor next-hop-unchanged
To: "But Nicky" <lyredhair_at_gmail.com>
Cc: "Cisco certification" <ccielab_at_groupstudy.com>
Date: Monday, August 3, 2009, 1:35 AM

Hi Nguyen,

Essentially, you put this command on the "remote" end of your EBGP peering
session. When this command is applied, the router will not change the BGP
next-hop. It allows it to "pass through". Imagine you have 3 router setup
doing eBGP like this:

RTR A ------ RTR B ------ RTR C

RTR A and RTR B are in AS 65001. RTR C is in AS 65002. If you applied this
command on RTR B with the peering to RTR A , when RTR B sends routes to RTR
C the next-hop would still be RTR A ...or "unchanged."

HTH

On Mon, Aug 3, 2009 at 12:37 AM, But Nicky <lyredhair_at_gmail.com> wrote:

> Dear Group,
>
> Any detail explanations and examples for this command?
> I have jut read in "Command Reference", but I am confusing about this
> command.
> Many thanks.
>
> Kind regards,
> But Nguyen.
>
>
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--
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Joe Astorino - CCIE #24347 R&S
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