Question

Can't run sshd in debug mode

Posted May 16, 2017 11.2k views
Linux Basics CentOS

I have a CentOS 7 droplet. I want to debug sshd. I stop the sshd service. And then do /usr/sbin/sshd -d. I get an error that connection is refused by the tcp wrapper.

Screenshot of sshd console output is here: https://snag.gy/l0HKiL.jpg

I’ve looked at these two articles and googled a bunch but no luck.

https://lists.debian.org/debian-user/2003/04/msg03552.html
https://www.akadia.com/services/ssh_tcp_wrapper.html

I imagine that the problem has something to do with what’s in my /etc/hosts.allow or /etc/hosts.deny. I tried adding an entry into the empty hosts.allow:

sshd: localhost

No luck.

/etc/hosts.deny just has a pile of entries for IPs that have been denied.

I am able to ssh to localhost from the droplet so the problem is more subtle than the machine being blocked from ssh'ing to itself.

Thanks.
Sol

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1 answer

@digitalocean3a334a72f3e85e

Have you tried running SSH on another port as a part of the command?

i.e.

sudo /usr/sbin/sshd -ddd -p 2200

You don’t have to specifically use 2200, any port that’s open and not in use should work.

The added d’s simply increase the verbosity of the output.

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