prefix can't be export by BGP

[智慧雨泽]

Hi, bird user
       It seems that the image attachment cannot be seen by others, so I
resend it (
       I want to export 2602:feda:ab4::/48. I wrote 「if bgp_export() then
accept」 in the BGP template, but it was not exported to BGP correctly. But
bgp_export() outputs 2602:feda:ab4::/48.
      I can't find the BGP in the bird document under what circumstances
will not export prefix, please tell me, thanks!

bird> show route export Hurricane_Electric_LLC
Table master6:
2a10:cc44:100::/44   unicast [UNM_Exch_RS2 2021-08-13 from
2602:ffb1:200:0:192:34:27:253] * (100) [AS38281i]
       via 2602:ffb1:200:0:192:34:27:6 on ens19
2a10:cc44:109::/48   unicast [LL_IX 15:22:24.526] * (100) [AS38281i]
       via 2602:feda:ab2:5247:5247:5247:5247:5247 on ll_ix
2001:df6:9f80::/48   unicast [EVIX_RS1 2021-08-13 from
2602:fed2:fff:ffff::1] * (100) [AS38281i]
       via 2602:fed2:fff:ffff::107 on ens20
2602:feda:ab2::/48   unicast [LL_IX 2021-08-15] * (100) [AS141011i]
       via 2602:feda:ab2:5247:5247:5247:5247:5247 on ll_ix
bird>


bird> show route where  bgp_export() all
Table master6:
2602:feda:ab2::/48   unicast [LL_IX 2021-08-15] * (100) [AS141011i]
       via 2602:feda:ab2:5247:5247:5247:5247:5247 on ll_ix
       Type: BGP univ
       BGP.origin: IGP
       BGP.as_path: 141011
       BGP.next_hop: 2602:feda:ab2:5247:5247:5247:5247:5247
fe80::200:5efe:5bd:ff6b
       BGP.local_pref: 100
2602:feda:ab4::/48   unreachable [BGP_Prefix 2021-08-13] (200)
       Type: static univ
bird>


template bgp tpl_bgp {
graceful restart on;
local as LOCAL_ASN;
ipv6 {
next hop self;
import filter peer_in_v6;
#export where bgp_export();
export filter{
#if my_opt_prefix() then bgp_path.prepend(LOCAL_ASN);
if bgp_export() then accept;
if bgp_export_downstream() then accept;
else reject;
};
};
}