Same problem here. MTU of the server is 1500, changing client MTU to the same value doesn't fix it.
Testing with ping, 1300 byte pings make it through fine, so tried setting client MTU to that on both client and server. No dice. Server version is OpenSSH_5.9p1 Debian-5ubuntu1.4, OpenSSL 1.0.1 14 Mar 2012. A client running OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013 can connect. A client running OpenSSH_6.6.1p1 Ubuntu-2ubuntu2, OpenSSL 1.0.1f 6 Jan 2014 *cannot* connect. Successful connection: % ssh -vv [redacted] OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to [redacted] port 22. debug1: Connection established. debug1: identity file /home/meta/.ssh/identity type -1 debug1: identity file /home/meta/.ssh/identity-cert type -1 debug1: identity file /home/meta/.ssh/id_rsa type -1 debug1: identity file /home/meta/.ssh/id_rsa-cert type -1 debug1: identity file /home/meta/.ssh/id_dsa type -1 debug1: identity file /home/meta/.ssh/id_dsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1.4 debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.4 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.3 debug2: fd 3 setting O_NONBLOCK debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ssh-rsa-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,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,hmac-sha1,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: 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: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256 debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac...@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac...@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,z...@openssh.com debug2: kex_parse_kexinit: none,z...@openssh.com 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: found hmac-md5 debug1: kex: server->client aes128-ctr hmac-md5 none debug2: mac_setup: found hmac-md5 debug1: kex: client->server aes128-ctr hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug2: dh_gen_key: priv key bits set: 126/256 debug2: bits set: 496/1024 debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Host '[redacted]' is known and matches the RSA host key. debug1: Found key in /home/meta/.ssh/known_hosts:3 debug2: bits set: 487/1024 debug1: ssh_rsa_verify: signature correct debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: /home/meta/.ssh/identity ((nil)) debug2: key: /home/meta/.ssh/id_rsa ((nil)) debug2: key: /home/meta/.ssh/id_dsa ((nil)) debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password debug1: Next authentication method: gssapi-keyex debug1: No valid Key exchange context debug2: we did not send a packet, disable method debug1: Next authentication method: gssapi-with-mic debug1: Unspecified GSS failure. Minor code may provide more information Cannot determine realm for numeric host address debug1: Unspecified GSS failure. Minor code may provide more information Cannot determine realm for numeric host address debug1: Unspecified GSS failure. Minor code may provide more information debug1: Unspecified GSS failure. Minor code may provide more information Cannot determine realm for numeric host address debug2: we did not send a packet, disable method debug1: Next authentication method: publickey debug1: Trying private key: /home/meta/.ssh/identity debug1: Trying private key: /home/meta/.ssh/id_rsa debug1: Trying private key: /home/meta/.ssh/id_dsa debug2: we did not send a packet, disable method debug1: Next authentication method: password Failed connection: % ssh -vv [redacted] OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014 debug1: Reading configuration data /home/meta/.ssh/config 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 [redacted] port 22. debug1: Connection established. debug1: identity file /home/meta/.ssh/id_rsa type 1 debug1: identity file /home/meta/.ssh/id_rsa-cert type -1 debug1: identity file /home/meta/.ssh/id_dsa type -1 debug1: identity file /home/meta/.ssh/id_dsa-cert type -1 debug1: identity file /home/meta/.ssh/id_ecdsa type -1 debug1: identity file /home/meta/.ssh/id_ecdsa-cert type -1 debug1: identity file /home/meta/.ssh/id_ed25519 type -1 debug1: identity file /home/meta/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1.4 debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.4 pat OpenSSH_5* compat 0x0c000000 debug2: fd 3 setting O_NONBLOCK debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: curve25519-sha...@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa-cert-...@openssh.com,ssh-rsa-cert-...@openssh.com,ssh-rsa,ecdsa-sha2-nistp256-cert-...@openssh.com,ecdsa-sha2-nistp384-cert-...@openssh.com,ecdsa-sha2-nistp521-cert-...@openssh.com,ssh-ed25519-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,ssh-dss 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: 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-md5-96 debug2: 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: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256 debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-...@lysator.liu.se debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac...@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac...@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd...@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,z...@openssh.com debug2: kex_parse_kexinit: none,z...@openssh.com 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-md5 debug1: kex: server->client aes128-ctr hmac-md5 none debug2: mac_setup: setup hmac-md5 debug1: kex: client->server aes128-ctr hmac-md5 none debug1: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY [locks up] What's weirder is that I have another server running Ubuntu 12.02LTS, and that one responds fine. Transcript from SSH to that system: meta@w510 % ssh -vv [redacted] OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014 debug1: Reading configuration data /home/meta/.ssh/config 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 [redacted] port 22. debug1: Connection established. debug1: identity file /home/meta/.ssh/id_rsa type 1 debug1: identity file /home/meta/.ssh/id_rsa-cert type -1 debug1: identity file /home/meta/.ssh/id_dsa type -1 debug1: identity file /home/meta/.ssh/id_dsa-cert type -1 debug1: identity file /home/meta/.ssh/id_ecdsa type -1 debug1: identity file /home/meta/.ssh/id_ecdsa-cert type -1 debug1: identity file /home/meta/.ssh/id_ed25519 type -1 debug1: identity file /home/meta/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1.4 debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.4 pat OpenSSH_5* compat 0x0c000000 debug2: fd 3 setting O_NONBLOCK debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: curve25519-sha...@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa-cert-...@openssh.com,ssh-rsa-cert-...@openssh.com,ssh-rsa,ecdsa-sha2-nistp256-cert-...@openssh.com,ecdsa-sha2-nistp384-cert-...@openssh.com,ecdsa-sha2-nistp521-cert-...@openssh.com,ssh-ed25519-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ssh-dss-cert-...@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,ssh-dss 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: 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-md5-96 debug2: 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: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256 debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,arcfour debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,arcfour debug2: kex_parse_kexinit: hmac-sha1,hmac-ripemd160 debug2: kex_parse_kexinit: hmac-sha1,hmac-ripemd160 debug2: kex_parse_kexinit: none,z...@openssh.com debug2: kex_parse_kexinit: none,z...@openssh.com 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: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: RSA d1:cb:3e:bf:8a:b1:f2:44:22:14:66:84:be:c2:c1:89 debug1: Host '[redacted]' is known and matches the RSA host key. debug1: Found key in /home/meta/.ssh/known_hosts:7 debug1: ssh_rsa_verify: signature correct debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: /home/meta/.ssh/id_rsa (0x7ff0476f2460), debug2: key: /home/meta/.ssh/id_dsa ((nil)), debug2: key: /home/meta/.ssh/id_ecdsa ((nil)), debug2: key: /home/meta/.ssh/id_ed25519 ((nil)), debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password debug1: Next authentication method: publickey debug1: Offering RSA public key: /home/meta/.ssh/id_rsa debug2: we sent a publickey packet, wait for reply debug1: Server accepts key: pkalg ssh-rsa blen 279 debug2: input_userauth_pk_ok: fp e5:2c:d4:f8:4f:63:c3:ab:e7:ac:10:5e:84:ee:40:60 debug1: key_parse_private2: missing begin marker debug1: key_parse_private_pem: PEM_read_PrivateKey failed debug1: read PEM private key done: type <unknown> [etc] I also have other non-Ubuntu servers behind the same VPN, and they respond fine. So it's some strange interaction of SSH versions, protocols, and the VPN. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1254085 Title: ssh fails to connect to VPN host - hangs at 'expecting SSH2_MSG_KEX_ECDH_REPLY' To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1254085/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
