BGP + anycast

[beren43]

Hi,

The task is to provide balancing and fault tolerance of the freeradius service by means of BGP anycast ip on the basis of two servers (not one, as at the moment). The plan is as follows: configure a different address on the lo interface (10.15.12.6 ) using bird to configure the announcement. Here's my version.

router id 10.10.2.28;

listen bgp address
filter anycastfr {

if net = 10.15.12.6/24 then accept;
}

protocol kernel {
persist;
scan time 20;
import all;
export all;
}

protocol bfd {
interface "ens192" {
interval 200 ms;
multiplier 3;
};
}

protocol static vroute {
route 10.15.12.6 via 10.10.2.28 ;

}

protocol bgp {
bfd;
export filter anycastfr
export where proto = "vroute";
}

Is that correct ?

 

[Scott Laird]

I haven't touched bird in a while, but if you're having problems, consider using exabgp (Exa-Networks/exabgp), which is basically designed for this use and comes with examples.

 

[necr]

You’re missing BGP neighbor configuration, also you should not have a static route. Your kernel route (special /24, which is supposedly some loopback interface - you’d be fine with /32 too there) should be in BGP export filter. Other thing is that this route must be withdrawn by disabling the loopback interface whenever your service is not working (i.e PID doesn’t exist anymore or systemd unit dead). For bird, there’s anycast-helper script available on Github, for ExaBGP as listed above there’s a tried and true Python built-in script available that does the same.