IPv6 next-hop with incorrect link-local address received

[Sebastian Neuner]

Hey,

> ignore-connected-check

Well, that actually works. I should go tell the TAC ;-)

On the bird-side we need to have "gateway recursive".


> Perhaps you can use:
> 
>   gw = bgp_next_hop;

Thanks, we'll try that!


> And you can use:
> 
>   bgp_next_hop = bgp_next_hop;

Maybe this could be mentionend in the docs?

This actually sets the right next-hop, but for some reason it sets the
route to the wrong interface (i.e. to the Cisco).


Anyway, thank you for your help!


Best regards,
Sebastian



On 10.08.18 14:07, Ondrej Zajicek wrote:
> On Fri, Aug 10, 2018 at 12:35:48PM +0200, Sebastian Neuner wrote:
>> Hi all,
>>
>> So now the next-hop in the BGP update looks like this:
>>
>>>  Next hop network address (32 bytes)
>>>    Next Hop: xxxx:xxxx:c02::28
>>>    Next Hop: fe80::28a:96ff:fecc:c10
>>
>> The GUA next-hop is correct and points to a VM on the server (i.e. not
>> on the /127). The link-local next-hop points to the Cisco.
>> Unfortunately, this is the one, bird uses to install the route in the
>> kernel.
>>
>> Am I missing something? Can I work around this somehow?
> 
> Perhaps you can use:
> 
>   gw = bgp_next_hop;
> 
> in import filter, which will set gateway based on GUA next-hop. And you
> can use:
> 
>   bgp_next_hop = bgp_next_hop;
> 
> which will clear up link-local next hop (because bgp_next_hop in filters
> only access the GUA part and resets link-local part when set).