Merge local SSH keys to work simultaneously

Question

I have been using SSH alot. I find myself creating new keys when something fails, like for git, then I lose communication to my other servers. I know going forward there should only be one set of locally generated keys, but for now, I need to merge the many /.ssh backups I've made so they can all be used simultaneously. How can I do this?

Answer 1

It is permissible to list many keys in your ~/.ssh/config. Or you can add many keys to an SSH agent.

Host *
    IdentityFile ~/.ssh/zoredache_20101108.id_rsa
    IdentityFile ~/.ssh/zoredache_20100211.id_rsa
    IdentityFile ~/.ssh/zoredache_20080514_id_rsa

Answer 2

In your ~/.ssh/config file try:

Host A
    IdentityFIle ~/.ssh/for-host-a.id

Host B
    IdentityFIle ~/.ssh/for-host-b.id

Host C
    IdentityFIle ~/.ssh/for-host-c.id

A session setup only allows 3 authentication attemps before the connection is dropped. Think of that as a 3 ID file limit. With the above, you can ssh to host A and it will use just that ID file. ssh to host B and it uses a different one, and so on.