Source Address Dependent Routing for BIRD

[Dean]

On 03/06/2017 12:10 PM, Toke Høiland-Jørgensen wrote:
> Dean Luga <dluga93 at gmail.com> writes:
>
>>   Hmm, I have been running babeld with source-specific routes for quite
>>   some time and never run into this problem. Are you sure you didn't botch
>>   the netlink calls? ;)
>>
>> I don't think so, I even tested inserting the routes with ip route
>> without running bird. It was a documented behavior in net/ipv6/Kconfig
>> in the kernel source.
> Ah, I see. What was the specific route table entries that elicited this
> behaviour? And what kernel version? Will see if I can replicate it on my
> system...
>
> -Toke

I had a system with an address of 2001:db9:1::2 connected to another 
with an address of 2001:db9:1::3. With one route:

2001:db9:1::3 dev v0  metric 1024

Ping was successful. Adding a route with a wrong source address:

2001:db9:1::3 from 2001:db9:1::1 dev v0  metric 1024
2001:db9:1::3 dev v0  metric 1024

I got a network unreachable message. Adding another source constrained 
route with the correct source:

2001:db9:1::3 from 2001:db9:1::1 dev v0  metric 1024
2001:db9:1::3 from 2001:db9:1::2 dev v0  metric 1024
2001:db9:1::3 dev v0  metric 1024

Ping successful.