By default SSH, telnet or https management is disabled.
First of all we must have configured the management interface of the equipment, something similar to:
ASA-JMCristobal# sh run interface Management0/0
!
interface Management0/0
management-only
nameif management
security-level 100
ip address 10.1.1.10 255.255.255.0
Enable SSH
Step 1 – Configure the RSA keys
ASA-JMCristobal(config)# crypto key generate rsa modulus 1024
Keypair generation process begin. Please wait…
Step 2 – Set up at least one local user
ASA-JMCristobal(config)# username MyUser password MyPass privilege 15
Step 3 – Define that the authentication uses the local ASA database in SSH sessions.
ASA-JMCristobal(config)# aaa authentication ssh console LOCAL
Step 4 – Enable SSH and allow connections only to the management interface from any IP address:
ASA-JMCristobal(config)# ssh 0.0.0.0 0.0.0.0 management
You can define only some particular network segments or hosts to have SSH access, each network segment or host must be defined on a separate line. The above line management refers to the interface name and not the interface type/number.
Enable configuration by ASDM
ASDM is the GUI manager for the ASA.
Step 1 – Validate that a version of ASDM exists on the ASA
ASA-JMCristobal(config)# dir
Directory of disk0:/
805673907 -rw- 33696476 16:31:35 Nov 17 2020 asdm.bin
1 file(s) total size: 33696476 bytes
21475885056 bytes total (21285044224 bytes free/99% free)
If the file does not exist, upload a version compatible with the equipment via FTP, SCP, or other protocol.
Step 2 – Configure at least one local user.
ASA-JMCristobal(config)# username MyUser password MyPass privilege 15
Step 3 – Define that the http authentication uses the ASA local database.
ASA-JMCristobal(config)# aaa authentication http console LOCAL
Step 4 – Enable http server
ASA-JMCristobal(config)# http server enable
Step 5 – Allow http connections only for the management interface from any IP address:
ASA-JMCristobal(config)# http 0.0.0.0 0.0.0.0 management
You can define only some particular network segments or hosts that have access with the ASDM; each network segment or host must be defined on a different line. The above line management refers to the interface name and not the interface type/number.
Now all that remains is to log in through a web browser to the IP address of the ASA to download the ASDM, install it and finally connect through this application