Symptom

Unable to Connect between new and older XR versions by SSH due to 3DES-CBC cipher support removal.

Conditions

If Customer devices are on disparate versions like 5.x and 6.1.x/6.2.x/6.3.x, it will fail to connect via any of SSH applications due to weaker 3DES-CBC Cipher algorithm support not available on newer XR releases.

Workaround

Possible WA is to downgrade higher version Device to support 3DES-CBC ciphers or upgrade the unsupported version.

Further Problem Description