Failover BGP servers?

[Nico Schottelius]

Jeroen Massar via Bird-users <bird-users at network.cz> writes:

>> On 29 Mar 2024, at 10:48, Yasen Atanasov <yasen6275 at abv.bg> wrote:
>>
>> Hello,
>> Lets imagine I have 2 BGP servers announcing same subnet. BGP
>> sessions with upstream are in different VLAN. Both servers have
>> keepalived and all clients are using for default route the virtual
>> address. The idea is if I need to upgrade/rebuild one of the servers
>> the clients will still have connectivity trough the other server. Do
>> I need to do something special in the bird config or just announcing
>> the same net is enough?
>
> Just announce the same net and ensure you do not have 'state': connection tracking... otherwise you need to do connection tracking state handover and things become nasty very quick.

... and I'd even go one step further: if you are able to do
active-active routing, drop the whole keepalived madness. Just have the
routing IP setup on both systems in parallel and be done with it.

State sync in IPv6 only networks was unfortunately still broken last
time I checked, conntrackd requires/required IPv4 connectivity.

BR,

Nico


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