# Remote Access

> remote access to cisco equipment.

Published on 2021-09-14 | Updated on 2025-01-12 | Tags: cisco

https://xsec.fr/en/networking/acces-distants/

---

import Callout from '@shared/components/Callout.astro'
import { Tabs, Tab } from '@/components/ui/tabs'

<Callout title="Renaming" variant="note">
To name each equipment with a thoughtful nomenclature is to save time.
```txt title="SW1(config)#"
SW1 (Config) #HostName SW1
```
</Callout>

## Telnet

Telnet is the fastest way to configure, but is not secure.
It is necessary to assign a password:

```txt title="SW1(config)#"
SW1 (config) #reable secret my_mdp
```

To reach your Telnet equipment, you need an active VLAN with an IP address.

<Callout variant="tip">
It is advisable to use VLAN 99, to simplify the administration of equipment.
</Callout>

```txt title="SW1(config)#"
SW1 (config) #vlan 99
SW1 (config-vlan) #Exit
SW1 (Config) #INT VLAN 99
SW1 (Config-IF)#

%Link-5-Changed: VLAN99 interface, changed state to up
SW1 (Config-Iif) #ip Address 192.168.1.2 255.255.255.0
SW1 (Config-IF)#Exit
SW1 (Config) #ip Default-Gateway 192.168.1.254 /*LAN PANDERAL
```

- Activate Telnet:

```txt title="SW1(config)#"
SW1 (config)#LINE VTY 0 1
```

<Callout variant="note">
`0` is the line of the line.
`1 is the maximum number of simultaneous connections.
</Callout>

Line password configuration:

```txt title="SW1(config-line)#"
SW1 (Config-Line) #Password Mon_MDP
SW1 (Config-Line) #Login
```

### Command summary

Once your `VLAN 99` is created and addressed, that your `gateway` is well defined;
You can copy/paste these lines directly (by adapting your configuration), in your terminal:

<Tabs tabs={["Telnet", "SSH"]} client:load>
<Tab>

```txt title="Terminal"
conf t
int VLAN 99
IP Address 192.168.1.2 255.255.255.0
no shut
exit
IP Default-Gateway 192.168.1.1
LINE VTY 0 1
password mon_mdp
login
```

</Tab>
<Tab>

```txt title="Terminal"
conf t
int VLAN 99
IP Address 192.168.1.2 255.255.255.0
no shut
exit
IP Default-Gateway 192.168.1.1
IP Domain-Name 1234.com
Crypto Key Generate RSA
2048
IP SSH version 2
Username admin password mon_mdp
LINE VTY 0 1
login
Transport input ssh
```

</Tab>
</Tabs>

## SSH

The most secure means, it adds a layer of encryption.
Its configuration is initially, similar to Telnet:

```txt title="SW1(config)#"
SW1 (Config) #INT VLAN 99
SW1 (Config-Iif) #ip Address 192.168.1.2 255.255.255.0
SW1 (Config-IF) #No Shut
SW1 (Config-IF)#Exit
SW1 (Config) #ip Default-Gateway 192.168.1.1 /*LAN PANDERAL
```

- It is necessary to enter a domain name:

```txt title="SW1(config)#"
SW1 (Config) #IP Domain-Name 1234.com
```

- Generation of RSA encryption keys:

```txt title="SW1(config)#"
SW1 (Config) #crypto Key Generate RSA
The name for the keys will be: sw1.1234.com
Choose The Size of the Key Modulus in the Range of 360 to 2048 for your
General Purpose Keys.Choosing A Key Modulus Greater Than 512 May Take
At Few minutes.

How Many Bits in the Modulus [512]: 2048
% Generating 2048 Bit RSA Keys, Keys will be unpopable ... [OK]
```

<Callout variant="danger">
To avoid widespread safety faults with SSH V1, go to version 2:
```txt title="SW1(config)#"
SW1 (Config) #ip SSH version 2
```
</Callout>

- Configuration of a login/password:

```txt title="SW1(config)#"
SW1 (config) #username admin password mon_mdp
```

- Configuration of line 0, to declare that only 1 user on the SSH protocol will be authorized:

```txt title="SW1(config)#"
SW1 (Config) #line Vty 0 1
SW1 (Config-Line) #Login
SW1 (Config-Line) #transport Input SSH
```