LinuxQuestions.org
Share your knowledge at the LQ Wiki.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices


Reply
  Search this Thread
Old 07-30-2004, 02:48 PM   #1
iainr
Member
 
Registered: Nov 2002
Location: England
Distribution: Ubuntu 9.04
Posts: 631

Rep: Reputation: 30
Moving to new network doesn't work


I have a problem I've seen more than once and on different Linux systems. I normally see it when I want my laptop to temporarily connect to a different network; for example use the internal ethernet adapter to connect to a 192.168.0.x network; rather than my normal wireless connection to a 192.168.1.x network.

I take the wireless adapter down (or remove it completely) and configure the internal adapter to use DHCP. It picks up a DHCP address OK and the routing table looks fine. I can ping the local interface but when I try to ping other interfaces on the same network (which can ping each other and even ping my laptop) I get a "host destination unreachable" or similar error.

I have a few years experience with Unix networking and I've checked all the obvious stuff like phyical connectivity; but I'm a bit stumped. Does anyone have any ideas?
 
Old 07-30-2004, 03:40 PM   #2
ugenn
Member
 
Registered: Apr 2002
Posts: 549

Rep: Reputation: 30
Do you have a firewall up?
 
Old 07-30-2004, 03:48 PM   #3
ugenn
Member
 
Registered: Apr 2002
Posts: 549

Rep: Reputation: 30
Do you have a firewall up?
 
Old 07-31-2004, 10:35 AM   #4
iainr
Member
 
Registered: Nov 2002
Location: England
Distribution: Ubuntu 9.04
Posts: 631

Original Poster
Rep: Reputation: 30
Yes, but only a simple Shorewall configuration with a few open ports; nothing IP address specific. Might that cause a problem?
 
Old 07-31-2004, 11:17 AM   #5
ppuru
Senior Member
 
Registered: Mar 2003
Location: Beautiful BC
Distribution: RedHat & clones, Slackware, SuSE, OpenBSD
Posts: 1,791

Rep: Reputation: 50
*could* be a routing issue? perhaps traffic defaults to your Wireless... May be this will work

ping -I eth0 192.168.0.x

Last edited by ppuru; 08-01-2004 at 10:24 PM.
 
Old 08-01-2004, 05:37 PM   #6
ugge
Senior Member
 
Registered: Dec 2000
Location: Gothenburg, SWEDEN
Distribution: OpenSUSE 10.3
Posts: 1,028

Rep: Reputation: 45
Have a look at your routing table while on the temporary network, route -n
The line with destination set to 0.0.0.0 is your gateway setting, is this pointing to the right gateway on the temporary network?
If not then this setting might need to be configured on the DHCP server of the temporary network, or else you will have to set it manually every time.

If the routing table looks fine then I would bet on some setting in the firewall. Even a "simple" firewall setting in a firewall script usually set up the firewall rules quite strictly and specific for the present network. If you set a simple firewall it usually narrow the rules down so that it only considers your current ip range as LAN, all other addresses are considered WAN or foreign traffic.
 
  


Reply


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
disabling moving between work areas butthead Programming 1 02-08-2005 06:33 AM
Home Network Similar to Work Network Boffy Linux - Networking 2 08-05-2004 06:52 PM
copying/moving stalls when moving a lot of data to a usb stick =X= Linux - Hardware 10 07-30-2004 05:29 AM
Getting network to work LinuxBlackBox Linux - Hardware 5 05-12-2004 03:14 AM
home network and work network PlatinumRik Linux - Wireless Networking 2 02-24-2004 07:12 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 04:21 AM.

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