Hello,

I have issues trying to setup this :

   ISP A                ISP B
     |                    |
  Router A            Router B
 Main site  -------  Backup site
 1.1.1.0/25          1.1.1.128/25

I'd like that connections to the main site flow through ISP A, to the backup
site flow through ISP B, with backup through the other ISP if one fails.
So I set up openBGPd like this :
Router A :
AS 65001
network 1.1.1.0/25
network 1.1.1.128/25 set prepend-self 5

neighbor "ISP A" {
        remote-as 65002
}
neighbor "router B" {
        remote-as 65001
}
allow from any

Router B :
AS 65001
network 1.1.1.0/25
network 1.1.1.128/25 set prepend-self 5

neighbor "ISP B" {
        remote-as 65003
}
neighbor "router A" {
        remote-as 65001
}
allow from any

I'm still during the test phase, so to simulate ISPs routers I've put some
other openBSD boxes.
Their setup :
Router ISP A :
AS 65002
neighbor "Router A" {
        remote-as 65001
        announce default-route
}
allow from any

Router ISP B :
AS 65003
neighbor "Router B" {
        remote-as 65001
        announce default-route
}
allow from any

For now, I only have ISP A and router A set up.
My problem : the "set prepend-self 5" on router A prevents the network
1.1.1.128/25 from appearing into router ISP A RIB.
If I remove the option, everything is fine.

Bgpctl sh rib on router A :
Flags   destination             gateway         lpref   med     aspath          
                        origin
*>      0.0.0.0/0               "router ISP A"  100     0       65002           
                                i
AI*>    1.1.1.0/25              0.0.0.0         100     0                       
                                i
AI*>    1.1.1.128/25    0.0.0.0         100     0       65001 65001 65001 65001 
65001           i

Bgpctl sh rib on router ISP A :
Flags   destination             gateway         lpref   med     aspath          
                        origin
*>      1.1.1.0/25              "router A"              100     0       65001   
                                        i


Could someone tell me where is my mistake ?
Thank you very much.

--
Cordialement,
Pierre BARDOU

Reply via email to