Changed modem; cannot access router nor modem admin page anymore

[Andre S. Veteran]

Once again I fail at setting up networks and require your help.

I was previously on ADSL with a modem (Motorola Netopia 2210-02) and a router (Rosewill RNX-N150RT). The modem acted as the DHCP server and was plugged into one of the non-WAN ports of the router along with all the other computers. I could access the router on 192.168.1.1 (its default page), the computers on 192.168.1.2-6 and the modem on 192.168.1.254. I could access both router and modem admin pages with a web browser at these addresses.

Now we changed services and are now with a cable modem. I first tried pluggin the cable modem directly into a PC to check if it was working, I could access its admin page at 192.168.100.1 (it's a Motorola SB5101). After I verified it was connecting to the internet fine, I put the router between the two like I was doing before (both plugged into non-WAN ports) and rebooted the devices. I can access the internet just fine with all PCs now, but I can't access the admin pages anymore! 192.168.1.1 doesn't answer a ping (it says delay exceeded), 192.168.100.1 answers a ping but gives 324 (net::ERR_EMPTY_RESPONSE) when I try to access it through a web browser.

The default gateway for the PCs is still 192.168.1.1.

Any ideas?

[pes2013]

  On 05/12/2012 at 21:53, Dr_Asik said:

I was previously on ADSL with a modem (Motorola Netopia 2210-02) and a router (Rosewill RNX-N150RT). The modem acted as the DHCP server

Why?

  On 05/12/2012 at 21:53, Dr_Asik said:

and was plugged into one of the non-WAN ports of the router along with all the other computers.

Again, why?

  On 05/12/2012 at 21:53, Dr_Asik said:

I could access the router on 192.168.1.1 (its default page), the computers on 192.168.1.2-6 and the modem on 192.168.1.254. I could access both router and modem admin pages with a web browser at these addresses.

The only reason that makes sense, since you mentioned this, is that you can reach the modem and router admin pages but it doesn't make much sense why would you want to read the modem admin page.

  On 05/12/2012 at 21:53, Dr_Asik said:

Now we changed services and are now with a cable modem. I first tried pluggin the cable modem directly into a PC to check if it was working, I could access its admin page at 192.168.100.1 (it's a Motorola SB5101). After I verified it was connecting to the internet fine, I put the router between the two like I was doing before (both plugged into non-WAN ports) and rebooted the devices. I can access the internet just fine with all PCs now, but I can't access the admin pages anymore! 192.168.1.1 doesn't answer a ping (it says delay exceeded), 192.168.100.1 answers a ping but gives 324 (net::ERR_EMPTY_RESPONSE) when I try to access it through a web browser.

The default gateway for the PCs is still 192.168.1.1.

Any ideas?

Well, im interested why you don't plug it into the WAN port like a normal human being :p

[+Eternal Tempest MVC]

I suspect one of the routers has the same IP address to access the control panel as the modem.

See if you can change the base address of the router from 192.168.1.1 to 192.168.2.1

I might be off on this...

Or the modem is acting like a network, and the router is acting like a second router and going through the second router, it can't reach the specific IP of the modem.

(edit)

I think the problem is similar to what I had when I had two routers and devices could not see other device on the opposite router.

I essentially disabled DHCP on the 2nd router and pointed DHCP server control to the 1st one.

This made the 2nd router an extension of existing network vs standalone.

This allows all the devices on either router to see each other.

[Andre S. Veteran]

Well now this is getting interesting. I plugged the same PC back directly on the modem, rebooted the modem, and now I can't access its admin page at its address anymore, same error, 324.

Hm... it looks like I can access the page for about 10 seconds every time I reboot the modem, just when it starts. Then after that every attempt to access the page results in error 324. There's no reset button anywhere on the thing.

@pes2013 the modem acted as a DHCP server because it did so by default, so I simply disabled DHCP on the router. Everything was connected into non-WAN ports because it just worked that way.

[PGHammer]

  On 05/12/2012 at 22:07, Jason Stillion said:

I suspect one of the routers has the same IP address to access the control panel as the modem.

See if you can change the base address of the router from 192.168.1.1 to 192.168.2.1

I might be off on this...

Or the modem is acting like a network, and the router is acting like a second router and going through the second router, it can't reach the specific IP of the modem.

(edit)

I think the problem is similar to what I had when I had two routers and devices could not see other device on the opposite router.

I essentially disabled DHCP on the 2nd router and pointed DHCP server control to the 1st one.

This made the 2nd router an extension of existing network vs standalone.

This allows all the devices on either router to see each other.

The issue is multiple DHCP servers and they have identical IP addresses (the root addresses of the Class C block of 192.168.xxx.xxx are commonly used by all sorts of routers, xDSL and otherwise - 192.168.0.1, 192.168.1.1, and 192.168.100.1 - the first one is seldom used by non-Cisco or even non-Netgear routers, the second one is commonly used by routers and cable modems of all brands, and the last is used by most Motorola xDSL and cable modems, such as your Netopia and current SURFboard).

You will need to change the default IP block used by the router to a class D block further *downrange* (I generally use 192.168.101.xxx *or* 192.168.002.xxx - whichever floats your boat) - that way you can still access the modem's 192.168.100.1 homepage for diagnostics. (I have an ARRIS WBM-760A cable modem that uses the same IP defaults common to the Motorola SURFboards; this one, in fact, replaced a SURFboard SB-5120. It replaced the SURFboard due to it supporting DOCSIS 3.0 *and* gigabit - the SB-512x supported neither.)

[remixedcat]

when you change services it's always a good idea to reset BOTH devices (modem and router) to resolve any conflicts that both may have....

do the 30/30/30 reset and see if it helps.

you may have to do a hardware reset as well... this might resolve your url access problem as well...

also re-run the connection wizard on the router so it will auto-detect settings instead of doing it manually as well.

some routers have a quick setup url like setup.ampedwireless.com is how I can access my router's config. yours might be routerlogin.net or myrouter.com or whatever.

now if you have muliple devices that use that same url from one brand, for example, a router and an access point, or a router and a repeater, then you will need to access the setup url by typing in the second device's IP address, as there will be conflicts with the domain.

[Detection]

  On 05/12/2012 at 22:45, PGHammer said:

The issue is multiple DHCP servers

+1

[Andre S. Veteran]

  On 05/12/2012 at 22:45, PGHammer said:

The issue is multiple DHCP servers

The issue can't be multiple DHCP servers when I connect the modem directly to a PC, I can access the config page for the first 10 seconds and then after I get the same error 324.

Anyway this is ****ing the **** out of me. I set it up this way:

Modem set as DHCP server - doesn't seem to be any way to set it otherwise, anyway I don't have much time to get into its setting page

Router has DHCP disabled

Modem is plugged into WAN port of router

PCs are plugged into LAN ports of router

Booted both devices - internet worked for all computers including wireless. I could access the router at 192.168.1.1, but the modem was nowhere to be found.

Then it just randomly stopped working for every computer except for one, my brother was playing SC1 online and it was still working for him. I tried unplugging my ethernet cable from the router but that disconnected him as well, illogically.

So I tried rebooting both devices and that didn't work, couldn't even access the router.

So I factory resetted the router, now I could access it, but no internet.

Did the same thing I did before, disabled DHCP on the router, rebooted.

Now I get internet on all the computers that were connected on Ethernet at the time I rebooted. Those I connected after don't work. Those on wireless don't work. When I try ipconfig /renew, it says the DHCP server timed out. Those that don't work don't have default gateways. For those that have default gateways, trying to access that page at that gateway address (which doesn't start with 192.168...) does nothing.

Btw this thread should be under Internet Network and Security, misread the title section before I posted.

  On 05/12/2012 at 23:08, remixedcat said:

when you change services it's always a good idea to reset BOTH devices (modem and router) to resolve any conflicts that both may have....

It's a new modem and it doesn't seem to have any reset button. I factory resetted the router multiple times now (only way to get the connection back up when it goes down apparently).

[remixedcat]

does your router have a domain setup for accessing the config?

also does your modem have a backup battery?

[Crisp]

Can you change the IP range on the modem? If so, set modem to 192.168.0.1, same for DHCP server; 192.168.0.2 ~ 192.168.0.XXX

Then plug modem into WAN port on router, and set router IP to 192.168.1.1, with DHCP server as; 192.168.1.2 ~ 192.168.1.XXX

That way, you can access modem and router seperate. 192.168.0.1 for modem and 192.168.1.1 for router.

Edit: Nevermind, thought you were having problems with a DSL modem.

[Andre S. Veteran]

  On 06/12/2012 at 01:55, remixedcat said:

does your router have a domain setup for accessing the config?

What does that mean? The default address is 192.168.1.1.

  Quote

also does your modem have a backup battery?

I have no idea. It's a motorola SB5101U.

I think I'm starting to figure out what's going on. This doesn't work at all like a DSL modem. It only acts as a DHCP server while it's not connected to the internet; after that, it's just a bridge that gets a public IP address assigned from the ISP. So what I should probably do is set the router to act as DHCP server, disconnect it from the modem, reboot the modem, wait until it connects, and only then plug it into the router. Does that make sense? I'll try that asap.

[remixedcat]

well some routers have a domain setup for the router's config so if you forget the IP address or whatever you can still access the router's config by typing in a url into the address bar.

usually something like routerlogin.net myrouter.com or setup.myrouter.com or setup.routerconfig.com or whatever....

mine is setup.ampedwireless.com and it resolves to my router's IP 192.168.3.1 (but if it's changed it still will point to the router) mine has a domain option in the LAN settings

[Calum Veteran]

Thread moved, at the thread author's request

[+BudMan MVC]

"it's just a bridge that gets a public IP address assigned from the ISP."

Exactly -- before you were just using your router as Accesspoint for wireless sounds like - or you would of been double natting. Before you had a gateway device (modem/router combo) Now you just have a MODEM.. It just bridges you from your ethernet connection to the connection from your cable company.

It gives you a PUBLIC IP on the internet - so if you want to have multiple devices behind only 1 public IP, then you need a nat router.

So shutdown everything - since your modem will cache last mac connected to it. Then boot the modem, give it time to get online. Then connect your routers WAN port to the modem, and your pcs to one of the lan ports and you will be good to go.

[Andre S. Veteran]

  On 06/12/2012 at 13:47, BudMan said:

So shutdown everything - since your modem will cache last mac connected to it. Then boot the modem, give it time to get online. Then connect your routers WAN port to the modem, and your pcs to one of the lan ports and you will be good to go.

Yeah, I did exactly that yesterday and it finally worked.

Only problem remains now that I can't access the modem's configuration page, although that's not a huge deal. I don't even know on which address it's supposed to be. Its reserved address 192.168.100.1 returns error 324 when I contact it, which it seems to always do once it's connected to the internet. My router is configured to start IP addresses at 192.168.1.100, so I tried the first few, 100, 101, 102, 103, to no avail.

[+BudMan MVC]

Not sure what you mean by tried the first few? To access your modems interface? Why would it be on your private side?? Most cable modems default to 192.168.100.1 - I can access mine from my 192.168.1.0/24 network.

But this is not always the case. So are you using chrome, and you get this error?

Error 324 (net::ERR_EMPTY_RESPONSE): The server closed the connection without sending any data.

Now with my router I don't have any issues

But here is why you can have problems depending on what your router does. This is what you have

internet---modem (192.168.100.1) --- (publicIP.23.42.x) router (192.168.1.1) ---- (192.168.1.100) PC

So even if your modem is listening.. You run into this issue, your router has NO ipaddress on the 192.168.100.x network, it has a public IP on the interface that is connected to the modem. With say a gateway of publicIP.24.42.254 or something while your router has IP publicIP.24.42.67 that it got from your ISP.

Now your computers on the 192.168.1 network have a gateway of 192.168.1.1 -- your router. so when they try and go to say 24.45.16.42 or something... They know its not on the 192.168.1.0, so they send it to your router at 192.168.1.1, he says I don't have that network locally connected so it sends it to its gateway (your isp). That publicIP.24.42.254 address in my expample. Well that gateway is sure not going to know how to get to 192.168.100.1

So you get an error. Now depending on your router, you might be able to configure it to be able to talk to your modem 192.168.100.1 address even though it doesn't have an interface in that network. For example, with pfsense here are instructions on talking to the modem interface from behind pfsense

http://doc.pfsense.o...inside_firewall

it comes down to pretty much giving your router a VIP on its wan in the 192.168.100 network so it knows how to talk to your modems IP.

So some routers work, other don't - but like you said you should really not need to access your modems interface. If you do, connect your PC to it, and give it an address on the 192.168.100.x network.

[Koshur]

  Quote

If you do, connect your PC to it, and give it an address on the 192.168.100.x network.

+1

Makes more sense, one of the reasons you might ever want to access your modem page is in case you want to bypass and enable bridging your connection. Other than that you would seldom be accessing it.

[+BudMan MVC]

Cable modems are almost always bridged - if they do nat then they would be called a gateway not a "modem" ;)

One reason I could see to access is to verify what firmware you have installed from your ISP, and or signal strengths, view logs for errors and such. Only time I have accessed it is when doing screen shots for other users or if something off in connection to check signal levels, etc.

[Koshur]

My bad.. Obviously I was pointing to "ADSL modems" (i use one), totally forgot he's using a cable modem.

[+BudMan MVC]

Which brings up an issue I have with terminology that some makers use.. If the thing does NAT, then don't freaking call it a modem, call it a gateway if it has ability to connect to isp network, be it dsl, cable, cell, fiber or even sat, etc. and does NAT or can do NAT. If it can not do nat and just provides connection then its a modem, if it does nat and has ethernet for wan and lan then call it a router.

If these different terms were not wrongly interchanged then everyone would know the features your working with depending if you say you have a modem, router or gateway ;)

What gets me is when users say their "modem" when they are really talking about a gateway or router. If it can do NAT then its not really a modem ;) If you have a gateway and have just turned it into a bridge, then its a gateway in bridge mode, etc. etc..

For example uses say they are directly connected to their "modem" But that is really a router, and then they have a gateway in front of it so they are double natting, sometimes even triple natting and can not figure out why port forwarding works, etc. Because they added a wireless router to the mix and instead of using it as AP, they plugged it into their network using its wan, and now its also natting, etc. etc.

Good indication if its gateway or router is if it has more than 1 lan port. But in the DSL world, you see many gateways with only 1 lan port, etc. I really can not recall the last time I saw just a true dsl modem - they are almost always gateways these days. Some support bridge mode, others are locked into doing nat.

[+Warwagon MVC]

  On 11/12/2012 at 17:36, BudMan said:

Which brings up an issue I have with terminology that some makers use.. If the thing does NAT, then don't freaking call it a modem, call it a gateway if it has ability to connect to isp network, be it dsl, cable, cell, fiber or even sat, etc. and does NAT or can do NAT. If it can not do nat and just provides connection then its a modem, if it does nat and has ethernet for wan and lan then call it a router.

If these different terms were not wrongly interchanged then everyone would know the features your working with depending if you say you have a modem, router or gateway ;)

What gets me is when users say their "modem" when they are really talking about a gateway or router. If it can do NAT then its not really a modem ;) If you have a gateway and have just turned it into a bridge, then its a gateway in bridge mode, etc. etc..

For example uses say they are directly connected to their "modem" But that is really a router, and then they have a gateway in front of it so they are double natting, sometimes even triple natting and can not figure out why port forwarding works, etc. Because they added a wireless router to the mix and instead of using it as AP, they plugged it into their network using its wan, and now its also natting, etc. etc.

Good indication if its gateway or router is if it has more than 1 lan port. But in the DSL world, you see many gateways with only 1 lan port, etc. I really can not recall the last time I saw just a true dsl modem - they are almost always gateways these days. Some support bridge mode, others are locked into doing nat.

But it also acts as a DSL modem, so wouldn't a better term be "Modem router combo!"

[+BudMan MVC]

yes a modem/router combo is a "gateway"

http://en.wikipedia.org/wiki/Residential_gateway

[Mando]

  On 06/12/2012 at 02:23, Dr_Asik said:

What does that mean? The default address is 192.168.1.1.

I have no idea. It's a motorola SB5101U.

I think I'm starting to figure out what's going on. This doesn't work at all like a DSL modem. It only acts as a DHCP server while it's not connected to the internet; after that, it's just a bridge that gets a public IP address assigned from the ISP. So what I should probably do is set the router to act as DHCP server, disconnect it from the modem, reboot the modem, wait until it connects, and only then plug it into the router. Does that make sense? I'll try that asap.

as you say set the router to be your dhcp server and let the modem do its thing, Ive seen having to clone the Modems MAC address to the wireless router before I could gain net access from the wifi router. (last night infact on gfs mums Virgin UK link)

[+BudMan MVC]

"clone the Modems MAC address to the wireless router"

You mean clone the mac of the device that was connected before to the modem, say a different router or PC sure. But you wouldn't clone the modems mac to the router.

Sure if your isp has authed only a specific mac to talk to the modem, or you don't want to reset the modem to be able to connect a different device to clear the modems cache, sure. But that is not what the user is talking about - I went over the issue already. Once his router gets a public IP address, how would it know how to talk to a 192.168.100.0/24 address if its on say 24.13.1.0/24

[pes2013]

  On 05/12/2012 at 22:22, Dr_Asik said:

@pes2013 the modem acted as a DHCP server because it did so by default, so I simply disabled DHCP on the router. Everything was connected into non-WAN ports because it just worked that way.

Then why not disable the DHCP server on the modem and let the DHCP server on the router be the active one?

That's where Im kinda of confused :\ Maybe you did it on purpose for something in particular...