LinuxQuestions.org
Download your favorite Linux distribution at LQ ISO.
Home Forums Tutorials Articles Register
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 05-12-2016, 03:08 AM   #1
vwalker
LQ Newbie
 
Registered: Jan 2005
Location: Northern California
Distribution: Debian, Knoppix, Redhat, Slackware
Posts: 8

Rep: Reputation: 0
Smile Talk to different devices on different subnets


Hello. I'm trying to talk to my DSL modem, which is on a different subnet from my router. Here is how I am set up:

Default gateway (to my ISP): 123.231.123.1
My DSL modem: 123.231.123.22
Internal IP address for the modem (per modem manual): 192.168.0.1

My router: 192.168.1.1

My PC: 192.168.1.134
Subnet: 255.255.255.0

Sometimes the DSL router needs to be rebooted (sometimes = once a day). I can reboot it by going upstairs and power cycling it, but often that is not convenient. I would like to access the DSL modem through my PC browser to reboot it. I can talk to any device on 192.168.1.1 through 192.168.1.254, but I can't reach anything on the 192.168.0.x subnet.

Any good ideas on how to solve this problem? The modem is a Siemens Speedstream 4100. My router is a Linksys E4200.

Thanks!
 
Old 05-12-2016, 03:48 AM   #2
ferrari
LQ Guru
 
Registered: Sep 2003
Location: Auckland, NZ
Distribution: openSUSE Leap
Posts: 5,805

Rep: Reputation: 1140Reputation: 1140Reputation: 1140Reputation: 1140Reputation: 1140Reputation: 1140Reputation: 1140Reputation: 1140Reputation: 1140
Is this how you are set up?

(123.231.123.22)DSL modem(192.168.0.1) ---- (192.168.0.x?)Your LAN router(192.168.1.1/24) ---- (192.168.1.134/24)PC

From your description you have a router between you and the DSL device, and it is your router that should do the routing to allow you to reach 192.168.0.1, but perhaps worth checking that your DSL modem can be reached at the assumed address by connecting your PC to it directly and assigning 192.168.0.10 (with subnet mask 255.255.255.0). Can you then ping it successfully?

Maybe I've missed something.
 
Old 05-12-2016, 03:59 AM   #3
Emerson
LQ Sage
 
Registered: Nov 2004
Location: Saint Amant, Acadiana
Distribution: Gentoo ~amd64
Posts: 7,661

Rep: Reputation: Disabled
So your modem is doing NAT and your router is doing NAT. Why double NAT'ing? Does your modem still need rebooting if you put it in bridge mode?
 
Old 05-12-2016, 04:25 PM   #4
jefro
Moderator
 
Registered: Mar 2008
Posts: 21,982

Rep: Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626Reputation: 3626
I guess some setting in router could be messing that up but what happens when you try to access 192.168.0.1? Since it is outside of your ip/subnet then the router should try to forward to next and that should be your modem. I had a similar deal set up with a usb attached wireless modem on a router.

When I do use a dsl modem I sometimes make the modem a bridged device and it won't usually respond to the IP as you'd expect. It may respond to the wan ip.
 
Old 05-12-2016, 04:33 PM   #5
Emerson
LQ Sage
 
Registered: Nov 2004
Location: Saint Amant, Acadiana
Distribution: Gentoo ~amd64
Posts: 7,661

Rep: Reputation: Disabled
I'm no fan of double NAT, if modem does the NAT then the router should be acting as a switch/AP.
 
Old 05-14-2016, 12:18 PM   #6
sag47
Senior Member
 
Registered: Sep 2009
Location: Raleigh, NC
Distribution: Ubuntu, PopOS, Raspbian
Posts: 1,899
Blog Entries: 36

Rep: Reputation: 477Reputation: 477Reputation: 477Reputation: 477Reputation: 477
Quote:
Originally Posted by Emerson View Post
I'm no fan of double NAT, if modem does the NAT then the router should be acting as a switch/AP.
It's pretty typical for a home internet modem to NAT from the ISP. However, can the ISP device be fully trusted? I bought my own modem and still double NAT with my own trusted Linux box. Regardless of the reasons, double NAT is not uncommon and not wrong to do. /rant

Back on topic, to the OP.

By the way, your router should be able to automatically route your request to your modem IP (simply because of your own NAT). If this is not the case then you'll need to describe more about your setup. Post back with more details about your router.

We can't make assumptions about your network.

Last edited by sag47; 05-14-2016 at 12:20 PM.
 
  


Reply

Tags
reboot, router, subnet



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
Talk Talk to introduce controversial virus alert system Jeebizz Linux - News 0 11-25-2010 10:01 AM
configuring 2 nics to talk to two different subnets on a sles10sp3 server lodonnel Linux - Networking 3 11-30-2009 09:22 AM
How can two seemingly different subnets on the same segment talk toeach other? jdavis2 Linux - Networking 5 07-04-2008 11:42 PM
talk talk daemon configuration ananthkrk Red Hat 1 10-16-2004 11:45 AM
Making two subnets talk to each other. NetAX Linux - Networking 12 09-20-2004 02:41 AM

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

All times are GMT -5. The time now is 02:58 PM.

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
Open Source Consulting | Domain Registration