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Old 05-12-2016, 03:08 AM   #1
vwalker
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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
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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
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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
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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
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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
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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.
 
  


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