Trouble with IPv6 and VRFs: Cannot assign requested address

[Ralf Jung]

Hi,

On 28.12.18 15:43, Christoffer Hansen wrote:
> What about putting the interface with the IPv6 address of
> "2a03:2260:0:195::2" into the VRF in kernel?

It already is:

> 13: tun-up-b_ak at NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1280 qdisc noqueue master vrf_freifunk state UNKNOWN group default qlen 1000
>     link/gre 82.165.162.239 peer 185.66.195.1
>     inet 100.64.3.23/31 brd 255.255.255.255 scope global tun-up-b_ak
>        valid_lft forever preferred_lft forever
>     inet6 2a03:2260:0:195::2/64 scope global 
>        valid_lft forever preferred_lft forever
>     inet6 fe80::200:5efe:52a5:a2ef/64 scope link 
>        valid_lft forever preferred_lft forever

> What is the output of `ip vrf show vrf_freifunk`?

My "ip" seems to be too old:

> Object "vrf" is unknown, try "ip help".

; Ralf

> 
> On 28/12/2018 15:10, Ralf Jung wrote:
>> Hi all,
>>
>> I am playing around with VRFs in our network, and I am having trouble getting
>> bird6 to establish its BGP sessions inside a VRF.  Strangely, bird for IPv4
>> works with pretty much the same configuration.
>>
>> I have attached the full configuration.  The (I think) interesting bits are
>>
>>> template bgp ffrl_uplink {
>>>     table ffrl;
>>>     vrf "vrf_freifunk";
>>>     local as 64899;
>>>     import keep filtered;
>>>     import filter ebgp_ffrl_import_filter;
>>>     export filter ebgp_ffrl_export_filter;
>>>     next hop self;
>>>     direct;
>>> };
>>>
>>> protocol bgp ffrl_b_ak from ffrl_uplink {
>>>     source address 2a03:2260:0:195::2;
>>>     neighbor 2a03:2260:0:195::1 as 201701;
>>> };
>>
>> In the logs, all I get (with `debug all;` added) is
>>
>>> Dez 28 13:05:25 gw1.saar.freifunk.net bird6[24900]: ffrl_b_ak: Connecting to 2a03:2260:0:195::1 from local address 2a03:2260:0:195::2
>>> Dez 28 13:05:25 gw1.saar.freifunk.net bird6[24900]: ffrl_b_ak: Socket error: bind: Cannot assign requested address
>>> Dez 28 13:05:25 gw1.saar.freifunk.net bird6[24900]: ffrl_b_ak: Connection closed
>>> Dez 28 13:05:26 gw1.saar.freifunk.net bird6[24900]: ffrl_b_ak: Connect delayed by 5 seconds
>>
>> I tried adding `interface "tun-up-ffrl_b_ak";` (that's the interface which has
>> the address 2a03:2260:0:194::2), to no avail.  I also tried adding `interface
>> "vrf_freifunk";`, which made the error messages go away but still no peer is
>> listed in `birdc6 show route table ffrl`.
>> My IPv4 configuration is almost the same, and yet there finding peers works.
>> (Actually routing traffic doesn't work yet, but that may also be a problem with
>> our NAT setup.)
>>
>> Note that I have very little experience with BGP, we use it only in an internal
>> instance for peering with our uplink.
>>
>> >From some googling I found
>> <https://bird.network.cz/pipermail/bird-users/2017-August/011440.html> which
>> recommends adding `direct;`, but I already have that set.
>>
>> This is using bird 1.6.4, Linux 4.18, Debian stable.
>>
>> Any help would be greatly appreciated.
>>
>> Kind regards,
>> Ralf
>>
>