Download your favorite Linux distribution at LQ ISO.
Go Back > Forums > Linux Forums > Linux - Networking
User Name
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.


  Search this Thread
Old 12-01-2012, 09:19 AM   #1
LQ Newbie
Registered: Mar 2004
Posts: 21

Rep: Reputation: 0
Ping working in one direction only

I have a simple three node wireless linux network as follows:

hostname IP notes
crs laptop
cuda-host desktop wireless router ethernetted to WIFI modem

/etc/hosts on crs and cuda-host look like:
---> localhost crs -or- cuda-host crs cuda-host
From crs I can ping (and ssh) cuda-host but from cuda-host I can't ping (or ssh) crs. Instead I get:
craig@cuda-host:~$ ping crs
PING crs ( 56(84) bytes of data.
From cuda-host ( icmp_seq=1 Destination Host Unreachable
From cuda-host ( icmp_seq=2 Destination Host Unreachable
From cuda-host ( icmp_seq=3 Destination Host Unreachable
doing arp-scan from cuda-host I don't see crs. What I get is:
craig@cuda-host:~$ sudo arp-scan -I wlan0 -l
Interface: wlan0, datalink type: EN10MB (Ethernet)
Starting arp-scan 1.8.1 with 256 hosts ( 1c:af:f7:cc:85:cb D-LINK INTERNATIONAL PTE LIMITED 50:63:13:c1:7d:f5 Hon Hai Precision Ind. Co.,Ltd.

2 packets received by filter, 0 packets dropped by kernel
Ending arp-scan 1.8.1: 256 hosts scanned in 1.781 seconds (143.74 hosts/sec). 2 responded
D-LINK is my wireless modem. I thought .103 was my wireless modem. have never heard of the company Hon Hai. Arp-scan looks similar on crs

Any idea what's going on here?


Old 12-01-2012, 10:36 AM   #2
LQ Guru
Registered: Jan 2006
Location: Ireland
Distribution: Slackware & Android
Posts: 7,453

Rep: Reputation: 681Reputation: 681Reputation: 681Reputation: 681Reputation: 681Reputation: 681
/etc/hosts on crs and cuda-host look like:
---> localhost crs -or- cuda-host crs cuda-host <---
I don't like that.
It's good to have the 192.168.x network in /etc/hosts (Uf the IPs are static) but I would not list a box by it's ip and Hosts is for other boxes.

There are 3 boxes, so three lines in /etc/hosts line
router line
other box line (crs on cuda-host; cuda-host on crs)
Old 12-01-2012, 02:24 PM   #3
LQ Guru
Registered: Mar 2008
Posts: 15,142

Rep: Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142Reputation: 2142
Ping is a two way test. It proved what you wanted to know in the first test. That being a connection. The things that could stop it are the ability to offer or accept icmp. That could include the host, client or any device in between or firewalls or ports.

Last edited by jefro; 12-03-2012 at 11:38 AM.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
ping to server does not work until i ping from the other direction. weird! jstilby Linux - Networking 1 10-26-2011 07:42 AM
NFSv4 and idmapd working only in one direction afuerst Linux - Server 1 02-25-2011 11:07 PM
openvpn server and client cannot ping both direction odie_chan Linux - Networking 0 07-08-2006 12:06 AM
LAN/ADSL Router ping working but DNS ping fails R N Ghosh Linux - Networking 1 01-13-2006 07:44 AM
Need help\direction getting orinoco card working $hep Linux - Wireless Networking 1 03-18-2005 09:09 PM

All times are GMT -5. The time now is 11:46 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration