[CentOS] Host does not respond to nmap

Mon Aug 24 00:46:53 UTC 2015
Valeri Galtsev <galtsev at kicp.uchicago.edu>

On Sun, August 23, 2015 7:34 pm, Mark LaPierre wrote:
> Hey Y'all,
>
> I just set up a new old machine on my network.  I did a net install of
> CentOS 6.7 on it replacing an outdated copy of Win XP.  Of course I'm
> now in the throws of configuring the machine to be a useful member of
> society.
>
> [mlapier at peach ~]$ nmap -sn 192.168.15.0/24
>
> Starting Nmap 5.51 ( http://nmap.org ) at 2015-08-23 20:12 EDT
> Nmap scan report for 192.168.15.1
> Host is up (0.00043s latency).
> Nmap scan report for 192.168.15.100
> Host is up (0.00014s latency).
> Nmap scan report for 192.168.15.101
> Host is up (0.00065s latency).
> Nmap scan report for 192.168.15.104
> Host is up (0.00017s latency).
> Nmap scan report for mushroom.patch (192.168.15.105)
> Host is up (0.00015s latency).
> Nmap done: 256 IP addresses (5 hosts up) scanned in 15.30 seconds
>
> [mlapier at peach ~]$ ping -c 1 192.168.15.107
> PING 192.168.15.107 (192.168.15.107) 56(84) bytes of data.
> 64 bytes from 192.168.15.107: icmp_seq=1 ttl=64 time=0.175 ms
>
> --- 192.168.15.107 ping statistics ---
> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> rtt min/avg/max/mdev = 0.175/0.175/0.175/0.000 ms
> [mlapier at peach ~]$
>
> I can ssh onto 192.168.15.107 too.
>
> I spent a good part of the day trying to connect the FAHControl on my
> machine to the Folding at Home client on 192.168.15.107 without success.
> Maybe the reason why 192.168.15.107 does not appear on the nmap output
> has something to do with my lack of success connecting the control to
> the client.  Maybe not.
>
> I'm not having any problem connecting to the FAH client on
> 192.168.15.105 from my machine.  I even copied the FAH configuration
> file from 192.168.15.105 to 192.168.15.107 and then restarted the
> client.  Still no joy in Mudville.  I figure I should quit while I'm
> behind.  Anyone have any suggestions?
>

Do you have shell on the machine in question? If yes,

/sbin/ifconfig -a

/sbin/route

/bin/netstat -nap --inet

may help. (I'm sure you turned off firewall:

/etc/rc.d/init.d/iptables stop

).

Valeri

++++++++++++++++++++++++++++++++++++++++
Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
++++++++++++++++++++++++++++++++++++++++