method of authentication.

Hostname parameter should be set to the host that you are trying to

connect to. This is only required if you are using the "Host" parameter as

an alias to Hostname. Here I am using foo as an alias for ssh.foo.com.

When I try to connect to foo, I will actually connect to ssh.foo.com.

User is the user you want to connect to the host as.

IdentityFile should point to your RSA or DSA key. This is useful when you

have to specify different keys for different hosts. If not specified then

$HOME/.ssh/identity or $HOME/.ssh/id_dsa is read. For DSA keys you need to

use "IdentityFile2". Multiple identity files can be specified here; they

will all be tried in sequence.

One thing you need to be careful of is to make sure that your

defaults are placed after the host declarations. This is because every

option in ssh is set only the first time. Let's say, we have defined a

default parameter for user in the configuration file. It is set to foo2.

In a subsequent host section, we set the user to foo3. This will cause

problems because ssh first reads the default value of foo2 but when it

comes down to the host section it will ignore the user line because we

have already specified it up ahead in the configuration file. So make sure

that all the default parameters that you use across all hosts come last in

the file.

There are a lot more options here and the ssh man page is a great resource

for that. Or, you could always send me a mail.