sshit runs out of semaphores

DA Forsyth d.forsyth at
Tue Dec 2 04:56:00 PST 2008


I recently started (trying) to use sshit to filter the many brute 
force sshd attacks.

However, it has never worked on my box.  FreeBSD 7.0 p1.

This morning it would only give a message (without exiting)
   Could not create semaphore set: No space left on device
    at /usr/local/sbin/sshit line 322
Every time it gets stopped by CTRL-C it leaves the shared memory 
behind, allocated.

I am going to reboot later and double the number of semaphores (in 
I am running hobbit which uses 8, leaving only 2 free.  This may 
solve this issue, but I'd appreciate any ideas and experienced 

A side issue is that sshit will only filter rapid fire attacks, but I 
am also seeing 'slow fire' attacks, where an IP is repeated every 2 
or 3 hours, but there seem to be a network of attackers because the 
name sequence is kept up across many incoming IP's.  Is there any 
script for countering these attacks?
If not I'll write one I think.

       DA Fo rsyth            Network Supervisor
Principal Technical Officer -- Institute for Water Research

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