The function return true but it could not be export

[Alexander Zubkov]

Hello,

Maybe all your peers have the same AS number? BGP by default does not
pass routes among internal peers.

On Mon, Jun 7, 2021 at 3:07 PM 智慧雨泽 <zhihuiyuze at gmail.com> wrote:
>
> Hi everyone ,I'm using bird2.I wanna export 2602:feda:ab2::/48 from LL_IX to TOHU_IX.
> LL_IX      BGP        ---        up     12:24:16.896  Established
> TOHU_IX    BGP        ---        up     12:14:34.736  Established
>
> bird> show route protocol LL_IX where bgp_path.len = 0
> Table master6:
> 2602:feda:ab2::/48   unicast [LL_IX 12:26:32.410] * (100) [i]
>        via 2602:feda:ab2::1 on ll-ix
>
> So it returns True.
>
> bird> show route noexport TOHU_IX for 2602:feda:ab2::/48 all
> bird> show route export TOHU_IX for 2602:feda:ab2::/48 all
>
> But the prefix is not in export or noexport
> The configuration of the export filter is,So i think that must be exported.
> export filter {
> if bgp_export_all() then accept;
> # if (roa_check(r6, net, bgp_path.last_nonaggregated) ~ [ROA_INVALID, ROA_UNKNOWN]) then reject;
> # if is_bogon_asn() then reject;
> # if is_bogon_prefix() then reject;
> # accept;
> };
>
> bird> show route for 2602:feda:ab2::/48 all where bgp_export_all()
> Table master6:
> 2602:feda:ab2::/48   unicast [LL_IX 12:26:32.410] * (100) [i]
>        via 2602:feda:ab2::1 on ll-ix
>        Type: BGP univ
>        BGP.origin: IGP
>        BGP.as_path:
>        BGP.next_hop: 2602:feda:ab2::1
>        BGP.local_pref: 100
> bird>
>
> Why?
>
>
>
> On Sun, Jun 6, 2021 at 5:58 PM Maria Matějka <maria.matejka at nic.cz> wrote:
>>
>> Hello!
>>
>> I'd try:
>> * "show route noexport all" to see what may be the reason to drop the route
>> * add some logging to the filter to see why it is dropped
>>
>> BTW, what version are you using? As far as I remember, the BGP attributes are behaving differently on export in 1.6 and 2.0
>>
>> Maria
>>
>> On June 6, 2021 5:24:38 AM GMT+02:00, "智慧雨泽" <zhihuiyuze at gmail.com> wrote:
>>>
>>> Hi,The function i wrote correctly returns net.
>>>
>>> bird> show route 2602:feda:ab2::/48 where bgp_export_all()
>>> Table master6:
>>> 2602:feda:ab2::/48   unicast [LL_IX 02:19:31.236] * (100) [i]
>>>        via 2602:feda:ab2::1 on ll-ix
>>>
>>> But it could be export.
>>> bird> show route export TOHU_IX for 2602:feda:ab2::/48
>>> bird>
>>>
>>> I think that should be accept
>>> export filter {
>>> if bgp_export_all() then accept;
>>> # if (roa_check(r6, net, bgp_path.last_nonaggregated) ~ [ROA_INVALID, ROA_UNKNOWN]) then reject;
>>> # if is_bogon_asn() then reject;
>>> # if is_bogon_prefix() then reject;
>>> # accept;
>>> };
>>> };
>>> }
>>> Why is it not exported?
>>> The full configuration is.
>>>
>>> protocol bgp TOHU_IX {
>>> local as LOCAL_ASN;
>>> description "tohu ix IX-VPS BGP";
>>> direct;
>>> source address 2602:feda:ab5::1;
>>> neighbor 2602:feda:ab6::1%'tuhu-ix' as 141011;
>>> ipv6 {
>>> next hop self;
>>> import filter {
>>> if is_bogon_asn() then reject;
>>> if is_bogon_prefix() then reject;
>>> if (roa_check(r6, net, bgp_path.last_nonaggregated) = ROA_VALID) then reject;
>>> accept;
>>> };
>>> export filter {
>>> if bgp_export_all() then accept;
>>> # if (roa_check(r6, net, bgp_path.last_nonaggregated) ~ [ROA_INVALID, ROA_UNKNOWN]) then reject;
>>> # if is_bogon_asn() then reject;
>>> # if is_bogon_prefix() then reject;
>>> # accept;
>>> };
>>> };
>>> }
>>>
>>>
>>> function bgp_export() {
>>> if net !~ OUR_PREFIXES then return false;
>>> if is_bogon_asn() then return false;
>>> if is_bogon_prefix() then return false;
>>> if net_len_too_long() then {
>>> # print "net ", net, " prefix too long";
>>> return false;
>>> }
>>> if proto = "BGP_Prefix" then return true;
>>> if proto = "LL_IX" then{
>>> if bgp_path.len = 0 then{
>>> return true;
>>> }
>>> }
>>> if proto = "TOHU_IX" then{
>>> if bgp_path.len = 0 then{
>>> return true;
>>> }
>>> }
>>> return false;
>>> }
>>>
>>>
>>> function bgp_export_all() {
>>> if bgp_export() then {
>>> return true;
>>> }
>>>
>>> if source != RTS_BGP then{
>>> return false;
>>> }
>>> if is_bogon_asn() then return false;
>>> if is_bogon_prefix() then return false;
>>> return true;
>>> }
>>>
>>>
>>>
>>>
>>>
>>>