Remove invalid key from the known_hosts file for the IP address of a host

ssh-keygen -R `host hostname | cut -d " " -f 4`
Quick shortcut if you know the hostname and want to save yourself one step for looking up the IP address separately.

By: flart
2009-09-23 14:58:28

2 Alternatives + Submit Alt

What Others Think

nice! because I always delete the wrong line in the known_hosts file upon key errors, ever since the hostnames started being hashed by default. This is great, although I wonder if this will get each and every instance since the hosts' key may be listed under three different names: (1) the bare hostname, such as "bob", (2) the FQDN, such as "", or (3) the IP address. I'm guessing ssh-keygen just deletes entries corresponding to exactly what the input was.
bwoodacre · 596 weeks and 5 days ago
@bwoodacre Exactly. You need to run 'ssh-keygen -R' for every instance of the host in the known_hosts file. It's nevertheless more comfortable than editing it by hand IMO :-)
flart · 596 weeks and 4 days ago
Repeat after me: avoid backticks, they're evil ...
assarbad · 470 weeks and 5 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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