RE: BGP advertise non best routes?

Hi Guys,
You can installed the routes in your BGP routing table using the command
maximim-paths default is 1 but you can change it to 6. there is good example
in the CISCO BGP-4 Command and configuration handbook.

when BGP installed the both routes then it advertise these 2 routes :)
Take Care
 Roy

> From: Oluwagbenga_at_daitmail.com
> Date: Sun, 13 May 2012 20:53:30 +0100
> Subject: Re: BGP advertise non best routes?
> To: marcabel_at_gmail.com
> CC: john.matijevic_at_gmail.com; ccielab_at_groupstudy.com
>
> In the case of RIB failure "r>" BGP process will still consider the route
> as best path and advertise it to neighbor.
>
> So if you can induce a rib failure by lowering IGP AD on the router to
> prefer IGP route to BGP route. This should do the trick. RR will not use
> the BGP route, but will still see it as Best path and advertise it to
> neighbor.
>
> On 13 May 2012 20:07, marc abel <marcabel_at_gmail.com> wrote:
>
> > Thank you for your response john. I may not have explained what I am
trying
> > to do well enough.
> >
> >
> > what I am talking about is if you have two paths in the bgp table such as
> > this:
> >
> > R3(config-if)#do show ip bgp
> > BGP table version is 21, local router ID is 1.1.3.3
> > Status codes: s suppressed, d damped, h history, * valid, > best, i -
> > internal,
> > r RIB-failure, S Stale
> > Origin codes: i - IGP, e - EGP, ? - incomplete
> >
> > Network Next Hop Metric LocPrf Weight Path
> > * i100.100.1.0 10.1.2.254 0 100 0 500 i
> > *>i 10.1.1.254 0 100 0 500 200
i
> >
> > Your router will only advertise out the route it considers best to its
BGP
> > peer. So in this case it would only advertise the route through
10.1.1.254.
> > What I want is to be able to send both options to the next router in the
> > line and then let it choose based on weight or as path or something.
> >
> > *note I have applied "bgp bestpath as-path ignore" that is why this one
> > isn't preferring the shorter AS path.
> >
> >
> >
> >
> > On Sun, May 13, 2012 at 1:49 PM, john matijevic <john.matijevic_at_gmail.com
> > >wrote:
> >
> > > Good Afternoon Marc,
> > >
> > > "Is there any way to force BGP to advertise all of it's routes, even
ones
> > > it
> > > doesn't consider best? "
> > >
> > > You can use the network statement under the BGP process to advertise
> > > the connected networks. For routes learned via another protocol, you
> > > can use the redistribute command.
> > >
> > > Once you have all the routes that you want advertised you can use
> > > different filter techniques to advertise or bgp attributes command to
> > > prefer one path over another.
> > >
> > > Hope this helps.
> > >
> > > Regards,
> > > John
> > >
> > >
> > > On 5/13/12, marc abel <marcabel_at_gmail.com> wrote:
> > > > Is there any way to force BGP to advertise all of it's routes, even
> > ones
> > > it
> > > > doesn't consider best? Particularly looking for a way to make an iBGP
> > > peer
> > > > prefer a different route than it's route reflector.
> > > >
> > > >
> > > > Blogs and organic groups at http://www.ccie.net
> > > >
> > > >
Received on Wed May 16 2012 - 13:49:59 ART