OSPF authentication problem between Cisco and Bird

[Ondrej Zajicek]

On Sat, Mar 23, 2019 at 06:25:47PM +0100, Jérémie Vandeville wrote:
> Hi everyone
> 
> I apologise in advance, english is not my native language...
> 
> For study purpose, I'm trying to setup OSPFv2 between Bird 1.6.6 and a
> Cisco router.
> 
> protocol ospf test {
>     instance id 42;
>     area 0.0.0.0 {
>         interface "eth*" {
>             hello 2;
>             dead count 3;
>             authentication simple;
>             password "azerty";
>         };
>     };
>     export all;
> }

> 17:13:38.012494 IP (tos 0xc0, ttl 1, id 21850, offset 0, flags [none],
> proto OSPF (89), length 64)
>     192.168.42.43 > 224.0.0.5: OSPFv2, Hello, length 44
>     Router-ID 192.168.42.43, Backbone Area, Authentication Type: simple (1)
>     Simple text password: azerty
> 
> 17:13:38.012792 IP (tos 0xc0, ttl 1, id 7301, offset 0, flags [none], proto
> OSPF (89), length 72)
>     192.168.42.73 > 224.0.0.5: OSPFv2, Hello, length 52
>     Router-ID 1.1.1.1, Backbone Area, Authentication Type: unknown (10753)
> 
> 
> Can you tell me what I'm doing wrong ? If I try the "none" authentication,
> Bird send the code 10752 and the problem is the same...

Hi

This is expected behavior, RFC 6549 redefined authentication type field
from 16bit to 8bit, and is using higher 8bit as 'instance id'.

For compatibility with older implementations just do not set 'instance id'.
It has to be set on both sides to the same value anyways.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."