I'm attempting to set up SSH on a Cisco 2811 and having some difficulties.

The first step to this should be running crypto key generate rsa

I seem to be missing this though:

better#crypto key generate rsa
                  ^
% Invalid input detected at '^' marker.

better#

Furthermore, the only available commands I have in the crypto key namespace are lock and unlock, which seem to indicate a locked keypair (for which I don't know the password):

better#crypto key ?
lock    Lock a keypair.
unlock  Unlock a keypair.

better#crypto key unlock ?
rsa  RSA keys

better#crypto key unlock rsa
%% Please enter the passphrase: 
%% Unlocking failed.
.

better#

More or less, I'm asking what exactly this might mean, and if I actually do have certificates already here (used router)? Otherwise, how can I solve this? It's my first time configuring this feature, but I definitely believe it's part of my IOS.

Speaking of my IOS, I'm running the image c2800nm-advsecurityk9-mz.124-24.T6.bin

I'll also note that I have my hostname and ip domain-name configured. I'll also give you a dir flash: below if it's at all of use:

better#dir flash:
Directory of flash:/

    2  -rw-        2748  Jul 27 2009 14:03:52 +00:00  sdmconfig-2811.cfg
    3  -rw-      931840  Jul 27 2009 14:04:10 +00:00  es.tar
    4  -rw-     1505280  Jul 27 2009 14:04:32 +00:00  common.tar
    5  -rw-        1038  Jul 27 2009 14:04:46 +00:00  home.shtml
    6  -rw-      112640  Jul 27 2009 14:05:00 +00:00  home.tar
    7  -rw-     1697952  Jul 27 2009 14:05:26 +00:00  securedesktop-ios-3.1.1.45-k9.pkg
    8  -rw-      415956  Jul 27 2009 14:05:46 +00:00  sslclient-win-1.1.4.176.pkg
    9  -rw-    38732900   Dec 8 2011 06:28:56 +00:00  c2800nm-advsecurityk9-mz.124-24.T6.bin

64016384 bytes total (20598784 bytes free)
better#