What does `BGP.23 [t]: 00 00 ca 6a` mean?

[Marek Küthe]

Hello,

I recently joined an IXP and now I get some routes. Among others the
following:
2401:a400::/32       unicast [grc_rs1 07:07:17.427 from 2001:7f8:2:1::ca6a] * 
(100) [AS7477i]
        via 2001:7f8:2:1::1b1b on enp6s19
        Type: BGP univ
        BGP.origin: IGP
        BGP.as_path: 6939 7477
        BGP.next_hop: 2001:7f8:2:1::1b1b fe80::4288:2fff:febf:2662
        BGP.med: 0
        BGP.local_pref: 100
        BGP.community: (0,714) (0,2906) (0,6939) (0,12876) (0,12989) (0,13335) 
(0,15133) (0,15169) (0,16265) (0,16276) (0,16509) (0,20940) (0,22822) (0,32590) 
(0,48641) (0,49029) (0,57363) (51818,12)
        BGP.large_community: (202952, 6, 2) (202952, 1, 1) (202952, 2, 4) 
(202952, 3, 1) (202952, 5, 2)
        BGP.23 [t]: 00 00 ca 6a

What does `BGP.23 [t]: 00 00 ca 6a` mean? I have never seen this before
in bird.

I would appreciate an answer.

Greetings
Marek Küthe

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Description: OpenPGP digital signature