Re: Defines for mixed IPv6/IPv4

[Luiz Amaral]

Hello Nico,

I make separate defines per family (like you did) and then in my filters 
I just use:
    if (net.type = NET_IP4 && ! (net ~ ASxxx_IPV4)) then reject;
    if (net.type = NET_IP6 && ! (net ~ ASxxx_IPV6)) then reject;
Best,
Luiz

On 23/01/2024 14:13, Nico Schottelius via Bird-users wrote:
Hello bird users,

I am wondering how you handle matching both IPv6 and IPv4 prefixes
efficiently.

We have tons of blocks in our config like these:

define net_genauso_v6 = [
        2a0a:5480::/29+
];

define net_genauso_v4 = [
        185.203.113.0/24,
        185.116.114.0/24
];

And then later we have a function that combines them like this:

function is_genauso() -> bool
{
   if ((net ~ net_genauso_v6) ||
       (net ~ net_genauso_v4)) then {
       return true;
   }

   return false;
}

And then much later, we have various filters utilising the function, the
most simple one being:

filter genauso {
   if(is_genauso()) then accept;
   reject;
}

Which is then used in both IPv4 & IPv6 channels:

protocol bgp incoming_r2ge {
     ...

     ipv6 {
       import filter genauso;
       export none;
     };

     ipv4 {
       import filter genauso;
       export none;
       extended next hop on;
     };
}


Instead of writing a wrapper function for each peer/constellation, it
would be great if we could do something like that:

define net_genauso = [
        2a0a:5480::/29+,
        185.203.113.0/24,
        185.116.114.0/24
        ];

...
filter genauso {
   if(net ~ net_genauso) then accept;
   reject;
}
...

However as of bird 2.14, this results in the following error:

bridge:~nico# bird -f -c ./bird.conf
bird: ./bird.conf:208:23 Mixed IPv4/IPv6 prefixes in prefix set.

So my question is, how do you usually match on the two families? Do you
also write a wrapper function like above? Or do you have a smarter way?

BR,

Nico

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