debug1: expecting SSH2_MSG_KEX_ECDH_REPLY

debug-ssh.txt

https://unix.stackexchange.com/questions/722954/ssh-stuck-at-expecting-ssh2-msg-kex-ecdh-reply

Somehow I can connect on the second try, but never on the first try after waiting some minutes.
This only happens through the BGP session between the hosts, never when directly accessing the host.

not working:

debug3: kex_choose_conf: will use strict KEX ordering
debug1: kex: algorithm: sntrup761x25519-sha512@openssh.com
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY

working on second try:

debug3: kex_choose_conf: will use strict KEX ordering
debug1: kex: algorithm: sntrup761x25519-sha512@openssh.com
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31



working: -o KexAlgorithms=ecdh-sha2-nistp521

debug3: kex_choose_conf: will use strict KEX ordering
debug1: kex: algorithm: ecdh-sha2-nistp521
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31