Re: Aggregate in bgp

The "network" command in BGP works differently than other protocols. In
BGP that particular network (address + mask) must already exist in the
routing table. Does 155.1/16 exist there?

If not, the aggregate-address command is used to create a new prefix
based on sub-routes existing in the table.

HTH,

*Scott Morris*, CCIE/x4/ (R&S/ISP-Dial/Security/Service Provider) #4713,

JNCIE-M #153, JNCIS-ER, CISSP, et al.

JNCI-M, JNCI-ER

smorris_at_internetworkexpert.com

Internetwork Expert, Inc.

http://www.InternetworkExpert.com

Toll Free: 877-224-8987

Outside US: 775-826-4344

Knowledge is power.

Power corrupts.

Study hard and be Eeeeviiiil......

marish shah wrote:
> HI Expert,
> One Q, I'm doing one lab of bgp in this lab there is one
> task ( Advertise 155.1.0.0 with ,mask 255.255.0.0 to external ebgp router)
> now he did this thing through aggregate-address
>
> R6 which is connected with BB1 .R1 in bgp 100 and BB1 in bgp 54
> So on R6 configuration for advertise 155.1.0.0 255.255.0.0 to BB1
>
> R6
>
> neighbor 54.1.1.254 remote-as 54
> aggregate-address 155.1.0.0 mask 255.255.0.0
>
>
> So my Q is why he use this aggregate to advertise subnet .Y he didn't use
> network command ( network 155.1.0.0 mask 255.255.0.0 ) .
>
> If this Q is silly so plz forgive me but I really want to know y he did'nt
> do through this why.
>
> Thanks.
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Tue May 12 2009 - 10:34:41 ART