Re: bgp conditional route advertisement

Have a look at this lab that I wrote, it might help you:

http://micronics.nl/BGP-Conditional-Adv.pdf

On Mon, Sep 16, 2013 at 10:12 AM, Tony Singh <mothafungla_at_gmail.com> wrote:

> Hi Balaji
>
> This is a good question one which I have been scratching my head over, can
> you confirm if this is in your production environment or is it on gns/IOU
> or home lab if so please confirm platform/IOS version
>
> --
> BR
>
> Tony
>
> Sent from my iPad
>
> On 4 Sep 2013, at 14:58, BALAKRISHNAN Balaji <
> Balaji.BALAKRISHNAN_at_swift.com> wrote:
>
> > All,
> >
> >
> >
> > Any suggestion ?.. Configuration is as below
> >
> >
> >
> > ip route 3.3.3.3 255.255.255.255 1.1.1.1
> >
> >
> >
> > Router bgp 65000
> >
> > Network 3.3.3.3 mask 255.255.255.255
> >
> > neighbour 192.168.1.1 remote-as 65001
> >
> > neighbour 192.168.1.1 advertise-map ADVERTISE non-exist-map NONEXIST
> >
> > !
> >
> > Route-map ADVERTISE permit 10
> >
> > Match ip address 50
> >
> > !
> >
> > Access-list 50 permit 3.3.3.3
> >
> > !
> >
> > Route-map NONEXIST permit 10
> >
> > Match ip address 30
> >
> > !
> >
> > Access-list 30 permit 2.2.2.2
> >
> > !
> >
> >
> >
> > Thanx
> >
> > Balaji
> >
> >
> >
> > From: BALAKRISHNAN Balaji
> > Sent: Tuesday, September 03, 2013 5:31 PM
> > To: ccielab_at_groupstudy.com
> > Subject: bgp conditional route advertisement
> >
> >
> >
> > Hello all,
> >
> >
> >
> > I have a scenario that I am struggling to address a specific issue and
> would
> > like to hear your recommendation
> >
> >
> >
> > Announce the route 3.3.3.3 to the bgp neighbour only under the following
> > condition on the routes it receives from the backbone
> >
> >
> >
> > - Only if it has valid 1.1.1.1/32 route on the bgp table but
> no
> > valid route for 2.2.2.2/32
> >
> >
> >
> > It works fine under the normal situation when both 1.1.1.1 and 2.2.2.2
> exist
> > in the bgp table ( meaning conditional route does not get triggered) .
> But
> > when the router bounces its bgp connection to the backbone, it learns
> the
> > route 1.1.1.1/32 fraction of a second earlier than 2.2.2.2/32.. It
> causes
> > the conditional advertisement to kick in momentarily before withdrawing
> > immediately after which is causing some undesirable instability in the
> > network.. Can you recommend any work around to resolve this issue.
> >
> >
> >
> > Rgds
> >
> > Balaji
> >
> >
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> >
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-- 
*Narbik Kocharians
*CCSI#30832, CCIE# 12410 (R&S, SP, Security)
*www.MicronicsTraining.com* <http://www.micronicstraining.com/>
Sr. Technical Instructor
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