Public bug reported:
I can not connect from a freshly installed 14.04 box to a Cisco
CSR1000V. 12.04 connects with no issues.
Debugging this, the symptoms are identical to this bug report:
https://bugzilla.redhat.com/show_bug.cgi?id=1026430
see the logs below (hostnames, addresses, and usernames below are
edited).
Failing attempt (the default settings):
$ ssh -vvv username@router.example
OpenSSH_6.6, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to router.example [2001:db8::1] port 22.
debug1: Connection established.
debug1: SELinux support disabled
debug1: identity file /home/ubuntu/.ssh/id_rsa type -1
debug1: identity file /home/ubuntu/.ssh/id_rsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_ed25519 type -1
debug1: identity file /home/ubuntu/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6p1 Ubuntu-2ubuntu1
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-...@openssh.com,aes256-...@openssh.com,chacha20-poly1...@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se
debug2: kex_parse_kexinit:
hmac-md5-...@openssh.com,hmac-sha1-...@openssh.com,umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-ripemd160-...@openssh.com,hmac-sha1-96-...@openssh.com,hmac-md5-96-...@openssh.com,hmac-md5,hmac-sha1,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit:
hmac-md5-...@openssh.com,hmac-sha1-...@openssh.com,umac-64-...@openssh.com,umac-128-...@openssh.com,hmac-sha2-256-...@openssh.com,hmac-sha2-512-...@openssh.com,hmac-ripemd160-...@openssh.com,hmac-sha1-96-...@openssh.com,hmac-md5-96-...@openssh.com,hmac-md5,hmac-sha1,umac...@openssh.com,umac-...@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96debug2:
kex_parse_kexinit: none,z...@openssh.com,zlib
debug2: kex_parse_kexinit: none,z...@openssh.com,zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit:
diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
debug2: kex_parse_kexinit: hmac-sha1,hmac-sha1-96
debug2: kex_parse_kexinit: hmac-sha1,hmac-sha1-96
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit: none
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: setup hmac-sha1
debug1: kex: server->client aes128-ctr hmac-sha1 none
debug2: mac_setup: setup hmac-sha1
debug1: kex: client->server aes128-ctr hmac-sha1 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<7680<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
Connection closed by 2001:db8::1
Working attempt:
$ ssh -vvv -o
KexAlgorithms=diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
username@router.example
OpenSSH_6.6, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to router.example [2001:db8::1] port 22.
debug1: Connection established.
debug1: identity file /home/ubuntu/.ssh/id_rsa type -1
debug1: identity file /home/ubuntu/.ssh/id_rsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_ed25519 type -1
debug1: identity file /home/ubuntu/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6p1 Ubuntu-2ubuntu1
debug1: Remote protocol version 1.99, remote software version Cisco-1.25
debug1: no match: Cisco-1.25
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "router.example" from file
"/home/ubuntu/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file
/home/ubuntu/.ssh/known_hosts:1
debug3: load_hostkeys