From: Weidong Xiao (Weidong.Xiao@vi.net)
Date: Wed Sep 10 2003 - 10:17:19 GMT-3
If I put the following under R4:
neighbor R2 allowas-in 1
Will 192.168.1.0/24 be installed in R4's BGP table?
> -----Original Message-----
> From: Weidong Xiao
> Sent: 10 September 2003 14:02
> To: ccielab@groupstudy.com
> Subject: BGP--conditional advertise
>
>
> R1(AS1)-------R2(AS2)
> | |
> | |
> | |
> R3(AS3)-------R4(AS3)
> |
> |
> lo0:192.168.1.1/24
>
>
>
> Say 192.168.1.0/24 needs to be advertised primarily by R3,
> only when linke between R1 and R3 (or between R1 and R2)
> fails should R4 advertise this network.
>
> On R4, will the following config work?
>
> neighbor R2 advertise-map MATCH-MYNET non-exist-map MATCH-MYNET
> route-map MATCH-MYNET
> match ip prefix-list 1
> ip prefix-list 1 permit 192.168.1.0/24
>
> What concerns me is that when R4 receives 192.168.1.0/24 from
> R2, the prefix will be discarded before install to bgp table,
> so non-exist-map MATCH-MYNET will always be satisfied, and
> the prefix be advertised. But, anyway, R4 do receive that
> prefix from R2,...
>
> The question boiled down to where does non-exist-map check?
> bgp table or received prefix?
>
> According to command reference,"Any BGP route that is matched
> by the advertise-map route map will be advertised to the
> neighbor if the non-exist-map route map does not match any
> route in the BGP routing table.", it's likely that
> non-exist-map checks BGP table.
>
> I wonder if there is a way to fulfill the task?
>
>
> Many thanks,
> Weidong
> CC[N|D]P, CSS1
>
>
> ______________________________________________________________
> _________
> You are subscribed to the GroupStudy.com CCIE R&S Discussion Group.
>
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Wed Oct 01 2003 - 07:24:25 GMT-3