Client Configuration

Published on 10 Mar 2004
Tags #SSH

The most common use of the SSH client configuration in ~/.ssh/config is the definition of aliases for host with special requiements.

Host ALIAS
HostName HOST
Port 12345

There are a few options that you should be aware of which can all either appear in a host section or globally.

Security: The CheckHostIP option will provide some protection against ip spoofing whereas the StrictHostKeyChecking (no, ask, yes) command can even provent host key to be added to your ~/.ssh/known_hosts.
```
CheckHostIP yes
StrictHostKeyChecking ask
```
Forwarding agent connections: Whether this is enabled or not is controlled via the ForwardAgent option. See also agent forwarding.
Forwarding ports: These are defined via the ForwardLocal and the ForwardRemote options. For details see port forwarding.
Forwarding x11 connections: Whether this is enabled or not is controlled via the ForwardX11 option.
Authentication: It depends on your setup whether you intent to allow both methods of authentication on a host-per-host basis or globally. The following example contains the default settings:
```
PasswordAuthentication yes
PubkeyAuthentication yes
```
rhost or shost authentication: This is evil. Don’t use it.
```
HostbasedAuthentication no
RhostsRSAAuthentication no
```

Nicholas Dille