ddwrt router build 18946 upgrade ssh broken

It seems that as of version 17xxx the guys are DD-WRT switched from OpenSSH to Dropbear. No big deal really, except the SSH keys are not compatible with each other, thus preventing SSH from running.

To fix SSH:

• Enable Telnet
• Telnet into your router and run the following commands:
  1. cd /tmp/root/.ssh/
  2. rm authorized_keys
  3. rm ssh_host_dss_key
  4. rm ssh_host_rsa_key
  5. nvram unset sshd_rsa_host_key
  6. nvram commit
  7. reboot

Once the Router Restarts, SSH should be working, and when you try to login, you will get a prompt to accept the new Key Generated by DropBear

Props to Pinchiis blog for the how-to

Pinchii’s Blog » build 18946.