Re: BGP multihoming issue

Are you sure you are actually advertising the right networks and that they
are both getting to the other side on ISP2 when things are working
properly? If you try to advertise "network 1.1.1.0 mask 255.255.254.0" I
don't believe that will work because the actual route in your RIB would be
1.1.0.0/23 correct? I would start with a phone call with ISP2 when BOTH
links are up. They should be seeing both routes in their BGP table, one
from you and one from ISP1. One of course will be preferred over the other,
but you need to see if it is getting there at all first.

On Sun, Dec 6, 2009 at 12:55 AM, jack daniels <jckdaniels12_at_gmail.com>wrote:

> Hi guys,
>
> I have a scenario where customer connects to 2 diffrent ISP. Customer has
> taken a block of IP ADDRESS from APNIC ( lets says 1.1.0.0/23)
>
> Now via ISP1 I advertise 1.1.0.0/24 and 1.1.1.0/23<<<<<<Primary for
> 1.1.0.0/24 and secondary for 1.1.1.0/24
>
> Now via ISP2 I advertise 1.1.1.0/24 and 1.1.1.0/23<<<<<<Primary for
> 1.1.1.0/24 and secondary for 1.1.0.0/24
>
> ISSUE - when I shut down the link of ISP1 then my 1.1.1.0/24 works but MY
> 1.1.0.0/24 SUBNET IS NOT GOING THROUGH ISP.
> WHEN I CALLED ISP2 they say we see 1.1.0.0/23 VIA ISP1 STILL.
> <<<<<<<<<<POINT 1
>
>
> when we no shut the link to ISP1 then ISP2 say THEY RECIVE 1.1.0.0/23 FROM
> customer connected to ISP2.<<<<<<POINT 2
>
>
> Can some one help me with this issue or if some one has seen this issue in
> past ,,,,, why ISP2 is still recieving route from ISP1 when customer LINK
> to
> ISP1 is shutdown and
> why we are not preffering route for 1.1.0.0/23 from customer conneted to
> ISP2/
>
> Regards
>
>
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