RAdv protocol in failover router setup

[Nico Schottelius]

Hey Tore,

we are running active-active routers with bird, wihout VRRP as follows:

- router1: high priority
- router2: low priority

Sample config:

protocol radv {
    # Internal
    interface "eth1.10" {
         max ra interval 5;      # Fast failover with more routers
         other config yes;       # dhcpv6 boot
         default preference high;
         default lifetime 600;
    };
    # Server
    interface "eth1.11" {
         max ra interval 5;
         default preference high;
         default lifetime 600;
    };
}

Routing via EUI-64 based link local addresses.

This works fine with Linux servers, however Windows/Linux clients do not
necessarily seem to accept the higher/lower preference route.

Cheers,

Nico


Tore Anderson <tore at fud.no> writes:

> I am trying to use BIRD v2.0.8 to emit ICMPv6 RAs from a HA pair of routers.
>
> The default router address of the router (fe80::1) is failed over using the
> VRRP protocol, so it is only present on a single router at any given time.
>
> I have run into two challenges I cannot quite figure out how to solve:
>
> 1) How to make BIRD only emit RAs if the router is active, i.e., only on
> interfaces where the fe80::1 address is configured.
>
> (It appears that RAdv does not support the «interface "*" fe80::1/128 {};»
> syntax; it just complains «Interface name/mask expected, not IP prefix»).
>
> 2) How to make BIRD use the fe80::1 default router address as the source
> address of the emitted RAs instead of the EUI-64-generated link-local address
> (which will not fail over to the standby router in the event of a failure, and
> should therefore not be used as a router by the hosts receiving the RAs).
>
> I am grateful for any suggestions.
>
> Tore


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