Re: BGP AS-PATH PREPEND

I think your Acl is wrong. Try to match the whole network in the Acl as it
advertize in BGP Network statement.don't only match the hosts.Then As path
prepend will work

My 2 cents

Thanks

On Wed, Jan 8, 2014 at 9:53 AM, Cisco Fanatic <ebay_products_at_hotmail.com>wrote:

> Because I only want 10.100.60.11 (source) to go over Layer 2 (a name)
> 10.20.80.11 (destination). The rest should all be prepended.
>
> ip access-list extended OVER_L2
> permit ip host 10.100.60.11 host 10.20.80.11
>
> With your suggestion all the traffic will be prepended (longer AS path)
> and it
> will not be the best route.
>
>
> Date: Wed, 8 Jan 2014 16:36:40 +0000
> Subject: Re: BGP AS-PATH PREPEND
> From: sammybibs_at_gmail.com
> To: ebay_products_at_hotmail.com
> CC: mothafungla_at_gmail.com; ccielab_at_groupstudy.com
>
> I'm pretty sure the route map is wrong here,
>
> !!!Yours
>
> !
> !You match the ACL but don't do anything with it.
> !
>
> route-map AS_CHANGE permit 10
>
> match ip address OVER_L2
>
> !
> ! You then pre-pend everything via the match all in the next statement
> !
>
> route-map AS_CHANGE permit 20
>
> set as-path prepend 65500 65500 65500
>
> !
>
>
> !!!Suggestion
>
> !
> !You match the ACL but don't do anything with it.
> !
>
> route-map AS_CHANGE permit 10
>
> match ip address OVER_L2
> set as-path prepend 65500 65500 65500
> !
>
> \Sam
>
>
> On Wed, Jan 8, 2014 at 4:31 PM, Cisco Fanatic <ebay_products_at_hotmail.com>
> wrote:
>
> Sorry, cut-paste issue, too many notepad open.
>
>
> R1
>
> ++
>
>
> !
>
> router bgp 65500
>
> neighbor 10.255.0.26 route-map AS_CHANGE out
>
> !
>
> route-map AS_CHANGE permit 10
>
> match ip address OVER_L2
>
> !
>
> route-map AS_CHANGE permit 20
>
> set as-path prepend 65500 65500 65500
>
> !
>
> ip access-list extended OVER_L2
>
> permit ip host 10.100.60.11 host 10.20.80.11
>
> !
>
>
> It is still going over the other connection...
>
>
> R1#traceroute 10.20.80.11
>
> Type escape sequence to abort.
>
> Tracing the route to 10.20.80.11
>
> VRF info: (vrf in name/id, vrf out name/id)
>
> 1 10.255.255.1 4 msec 0 msec 4 msec
>
> 2 10.255.255.22 [AS 1] 4 msec 0 msec 4 msec
>
> 3 10.13.0.253 [AS 65501] 4 msec 4 msec 0 msec
>
>
>
>
>
>
>
> > Subject: Re: BGP AS-PATH PREPEND
>
> > From: mothafungla_at_gmail.com
>
> > Date: Wed, 8 Jan 2014 15:59:21 +0000
>
> > CC: ccielab_at_groupstudy.com
>
> > To: ebay_products_at_hotmail.com
>
> >
>
> > Where's your match extended ACL in route-map condition ?
>
> >
>
> > --
>
> > BR
>
> >
>
> > Tony
>
> >
>
> > > On 8 Jan 2014, at 15:47, Cisco Fanatic <ebay_products_at_hotmail.com>
> wrote:
>
> > >
>
> > > I understand how AS-PATH PREPEND works, but I am not able to make it
> work
>
> if I
>
> > > need to manipulate traffic paths only from a specific source to a
>
> specific
>
> > > destination.
>
> > >
>
> > > R1
>
> > > ++
>
> > >
>
> > > !
>
> > > router bgp 65500
>
> > >
>
> > > neighbor 10.255.0.26 route-map AS_CHANGE out
>
> > >
>
> > > !
>
> > > route-map AS_CHANGE permit 10
>
> > >
>
> > > set as-path prepend 65500 65500 65500
>
> > >
>
> > > !
>
> > >
>
> > > R2
>
> > > ++
>
> > >
>
> > > !
>
> > > router bgp 65501
>
> > >
>
> > > neighbor 10.255.0.25 route-map AS_CHANGE out
>
> > >
>
> > > !
>
> > > route-map AS_CHANGE permit 10
>
> > >
>
> > > set as-path prepend 65501 65501 65501
>
> > >
>
> > > !
>
> > >
>
> > > R1#sh ip bgp
>
> > > BGP table version is 196, local router ID is 10.255.255.2
>
> > > Status codes: s suppressed, d damped, h history, * valid, > best, i -
>
> > > internal,
>
> > > r RIB-failure, S Stale, m multipath, b backup-path, x
>
> > > best-external, f RT-Filter
>
> > > Origin codes: i - IGP, e - EGP, ? - incomplete
>
> > > Network Next Hop Metric LocPrf Weight Path
>
> > > *> 10.3.0.0/16 0.0.0.0 0 32768 ?
>
> > > *> 10.7.0.0/24 0.0.0.0 0 32768 ?
>
> > > *> 10.11.0.0/24 0.0.0.0 0 32768 ?
>
> > > *> 10.13.0.0/16 10.255.255.1 0 1 65501 ?
>
> > > * 10.255.0.26 0 0 65501
> 65501
>
> 65501
>
> > > 65501 ?
>
> > > *> 10.16.0.0/24 0.0.0.0 0 32768 ?
>
> > > *> 10.20.0.0/24 10.255.255.1 0 1 65501 ?
>
> > > * 10.255.0.26 28416 0 65501
> 65501
>
> 65501
>
> > > 65501 ?
>
> > >
>
> > > I need specific traffic from 10.100.60.11 (Source) to specific
>
> 10.20.80.11
>
> > > (Destination) over the 10.255.0.26 connection.
>
> > >
>
> > >
>
> > > 10.100.60.11
>
> > > _` 10.20.80.11
>
> > >
>
> > >
>
> > > Any thoughts?
>
> > >
>
> > >
>
> > > Blogs and organic groups at http://www.ccie.net
>
> > >
>
> > > _______________________________________________________________________
>
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>
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>
> >
>
> >
>
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>
> >
>
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>
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>
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>
>
>
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>
>
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>
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>
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>
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>
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Received on Wed Jan 08 2014 - 11:21:51 ART