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Subject: Re: SSH hung with an OpenSSH_6.6.1p1 --> OpenSSH_5.8p2_hpn13v11
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On 03/26/2015 21:25, Wu ShuKun wrote:
> Okay
> % ssh -v -o "KexAlgorithms diffie-hellman-group-exchange-sha1" 10.41.172.19
> OpenSSH_6.6.1p1, OpenSSL 1.0.1l-freebsd 15 Jan 2015
> debug1: Reading configuration data /etc/ssh/ssh_config
> debug1: Connecting to 10.41.172.19 [10.41.172.19] port 22.
> debug1: Connection established.
> debug1: identity file /home/wsk/.ssh/id_rsa type -1
> debug1: identity file /home/wsk/.ssh/id_rsa-cert type -1
> debug1: identity file /home/wsk/.ssh/id_dsa type -1
> debug1: identity file /home/wsk/.ssh/id_dsa-cert type -1
> debug1: identity file /home/wsk/.ssh/id_ecdsa type -1
> debug1: identity file /home/wsk/.ssh/id_ecdsa-cert type -1
> debug1: identity file /home/wsk/.ssh/id_ed25519 type -1
> debug1: identity file /home/wsk/.ssh/id_ed25519-cert type -1
> debug1: Enabling compatibility mode for protocol 2.0
> debug1: Local version string SSH-2.0-OpenSSH_6.6.1_hpn13v11 FreeBSD-20140420
> debug1: Remote protocol version 2.0, remote software version
> OpenSSH_5.8p2_hpn13v11 FreeBSD-20110503
> debug1: match: OpenSSH_5.8p2_hpn13v11 FreeBSD-20110503 pat OpenSSH_5*
> compat 0x0c000000
> debug1: SSH2_MSG_KEXINIT sent
> debug1: SSH2_MSG_KEXINIT received
> debug1: kex: server->client aes128-ctr hmac-md5 none
> debug1: kex: client->server aes128-ctr hmac-md5 none
> debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<3072<8192) sent
> debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
> Connection closed by 10.41.172.19
> %

Can you try stopping sshd on the server side and run /usr/sbin/sshd -Dd
then SSH in and see if the server provides a reason for disconnecting
the client?