[PLUG] Troubleshooting ssh

Paul Heinlein heinlein at madboa.com
Tue Sep 5 17:23:28 UTC 2017


On Tue, 5 Sep 2017, Rich Shepard wrote:

> On Tue, 5 Sep 2017, Paul Heinlein wrote:
>
>>  ping salmo
>
> Paul,
>
>  I should have mentioned in my original post that ping returns the 
> expected packages. I just rebooted the portable; ping works.
>
>>  Second, check that you can reach 22/tcp (or whatever port you use
>>  for ssh) on salmo from your other machine:
>>
>>  nmap -p 22 salmo
>
> $ nmap -p xxxxx salmo
>
> Starting Nmap 7.12 ( https://nmap.org ) at 2017-09-05 10:09 PDT
> mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is 
> disabled. Try using --system-dns or specify valid servers with --dns-servers
> Nmap scan report for salmo (192.168.55.1)
> Host is up (0.00028s latency).
> rDNS record for 192.168.55.1: salmo.appl-ecosys.com
> PORT      STATE  SERVICE
> xxxxx/tcp closed unknown
>
> Nmap done: 1 IP address (1 host up) scanned in 0.17 seconds
>
> $ ls /etc/resolv.conf
> nameserver 8.8.8.8
> nameserver 127.0.0.1
> nameserver 192.168.55.1
>
>  Wonder why nmap can't find the nameservers in /etc/resolv.conf.
>
>>  If not, try running 'iptables -L' or 'iptables-save' from the console on
>>  salmo to ensure there's no firewall blocking inbound SSH.
>
> # iptables -L
> Chain INPUT (policy ACCEPT)
> target     prot opt source               destination
>
> Chain FORWARD (policy ACCEPT)
> target     prot opt source               destination
>
> Chain OUTPUT (policy ACCEPT)
> target     prot opt source               destination
>
>>  Third, try running ssh from salmo to the other host.
>
>  This, too, fails. And so does pinging typha from salmo.

Hmm. The DNS failures worry me, but let's start elsewhere. When logged 
into salmo, can you 'ssh localhost' successfully?

-- 
Paul Heinlein
heinlein at madboa.com
45°38' N, 122°6' W


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