Troubleshooting SSH Compatibility pada Cisco Catalyst 3750 IOS Lawas
Mengatasi Error SSH “No Matching …” & Host Key Mismatch di Cisco Catalyst 3750 (IOS Lawas) 📌 Latar Belakang Banyak perangkat jaringan lawas, termasuk Cisco Catalyst 3750 dengan IOS 12.2(55)SE7 , hanya mendukung algoritma SSH generasi lama. Sementara itu, OpenSSH modern (Windows 11, Linux terbaru) secara default menonaktifkan algoritma lama demi keamanan. Akibatnya, koneksi SSH gagal meskipun IP reachable dan kredensial benar . 🔍 Gejala Masalah 1. Error KEX (Key Exchange) ssh <username>@<ip-address> Unable to negotiate with <ip-address> port 22: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1 2. Error MAC (Setelah KEX diperbaiki) Unable to negotiate with <ip-address> port 22: no matching MAC found. Their offer: hmac-sha1,hmac-sha1-96,hmac-md5,hmac-md5-96 3. Host Key Mismatch (setelah regenerasi key) WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! Host key verification failed. ...