I ran into the same issue connecting from 13.10 to 12.04. In order to fix I had to uncomment both the Ciphers line in virbal's fix and the MACs line.
-- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/174168 Title: expecting SSH2_MSG_KEX_DH_GEX_GROUP To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/174168/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
