Enabling SSH Communication Between 09.0.10 Devices and 08.0.95 Devices

[Sgatjens]

Devices running different FastIron releases may encounter SSH connection issues due to differences in default key exchange and host key algorithms.

For devices running FastIron release 09.0.10a to 09.0.10h, attempting to establish an SSH connection with a device running FastIron release 08.0.95 or earlier can lead to a mismatch in algorithms, preventing the SSH connection from being established. This problem occurs during the negotiation phase, where the server offers key exchange and host key algorithms that are not compatible with the default settings of the device running FastIron release 09.0.10a to 09.0.10h.

For devices running FastIron release 09.0.10j and later, RUCKUS recommends configuring specific key exchange and host key algorithms on the devices to resolve this issue and enable SSH communication. Please follow the procedure below to enable SSH communication with devices running FastIron release 08.0.95 or earlier:

device# configure terminal
device(config)# ip ssh key-exchange-method
ASCII string Enter algorithms separated by a space:
             diffie-hellman-group-exchange-sha256
             diffie-hellman-group14-sha256
             diffie-hellman-group16-sha512
             diffie-hellman-group18-sha512
             curve25519-sha256@libssh.org
             diffie-hellman-group14-sha1
             ecdh-sha2-nistp256
             ecdh-sha2-nistp384
             ecdh-sha2-nistp521
             curve25519-sha256
device(config)# ip ssh key-exchange-method diffie-hellman-group14-sha1
device(config)# ip ssh host
   host-key-method                 SSH host key method
device(config)# ip ssh host-key-method
ASCII string Enter algorithms separated by a space:
             ecdsa-sha2-nistp256
             ecdsa-sha2-nistp384
             rsa-sha2-512
             rsa-sha2-256
             ssh-rsa
device(config)# ip ssh host-key-method ssh-rsa