[zebra 23064] rookie bgp admin looking for help with configuration change

Hello Zebra users,

I am a veteran GNU/Linux sysadmin and developer, but a rookie BGP admin.  A
couple years back I was able to convince management to replace our CISCO WAN
router with a GNU/Linux solution running Zebra.  It has served us very well
since it has been in production (over 2 years now) with no errors.  I even had
the good opportunity of presenting a paper on the project at the National
Association of Broadcasters conference (NAB 2006) (
http://techweb.rfa.org/docs/NABgrau2006.pdf ).

The original/current configuration for the router was to choose "full transit
routing" where our Zebra BGP router would select the best path between the two
ISPs we are connected to (we have 2 class C subnets, let's call them
SUBNETALPHA[192.168.10.0/24] and SUBNETBETA[192.168.20.0/24]).  Our sample
configuration follows:

    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    !
    ! BGP config commands:
    !
    ! the RFA AS number, 3
    router bgp 3
        ! RFA networks to announce to neighbors   
        network 192.168.10.0/24
        network 192.168.20.0/24

        ! Teir 1 ISP neighbor
        neighbor 192.168.1.1 remote-as 1
        neighbor 192.168.1.1 distribute-list RFAANNOUNCE out

        ! Local ISP neighbor
        neighbor 192.168.2.1 remote-as 2
        neighbor 192.168.2.1 distribute-list RFAANNOUNCE out

    ! access list to only let out information on our two dmz subnets
    ! SUBNETALPHA
    access-list RFAANNOUNCE permit 192.168.10.0/24
    ! SUBNETBETA
    access-list RFAANNOUNCE permit 192.168.20.0/24
    access-list RFAANNOUNCE deny 0.0.0.0/0


Yesterday evening management came to me requesting that by Monday all traffic
from SUBNETALPHA go out via the Teir 1 ISP and all traffic from SUBNETBETA go
out via the Local ISP, with failover behaviour defaulting to the remaining
link if either should go down.

I have spent most of the day today reviewing Zebra documentation and CISCO
documentation on how to achieve this goal, but am honestly a rather weak BGP
admin.  I come to the community seeking advice, tips (or sample configurations
;-D) to help me achieve this goal.

regards,
donfede




-- 
Federico Grau
Free Software Developer and Sysadmin
Radio Free Asia
2025 M Street, NW
Suite 300
Washington, DC  20036
202-587-2046  Telephone
202-721-7468  Facsimile
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