Can I Connect Modem with Router to a Router ?

  Heefie 12:46 31 Oct 2007
Locked

When in Dublin I had a 3com ADSL modem connected to my phone line. The
Modem was connected by RJ45 cable to a 3com Wireless Router which had
an RJ45 cable connection to my main PC (this one) and all of the other
PCs picked up the Wireless signal ... never had a problem apart from
the occasional weak signal upstairs on the kids machines.

Since having the phone line here in Clara, the 3com modem has never
showed an ADSL line as being available, though the wireless router was
accessible (no internet though, obviously). UTV have now sent me a
Creative DSL Router (with all-in-one modem) that picked up the ADSL
signal the moment I plugged it in !!! I must point out at this
juncture that I moved all of my PC equipment myself, the removal men
never touched it, so I know it's all been treated perfectly.

If I run an RJ45 cable directly from the new modem/router to this PC
then I have Internet access as now, no problem at all. However, if I
then run that same RJ45 cable into the 3com Wireless Router & run an
RJ45 cable (brand new and supplied with the modem, it works on the
laptop perfectly, so the cable is OK) direct to this PC, basically the
exact same set up I had back in Dublin, I get no ADSL signal again,
though the Router menu is accessible via IE. There is no Wireless
signal to the other PCs either.

Anybody got any ideas what may be the problem and/or solution ?

I am wondering if this is something to do with both boxes being
"Routers", but at the end of the day, it's just an ADSL signal, why
should it be any different going directly to the PC or via the 3com
Router ?

  Taff™ 17:24 31 Oct 2007

bump - Please don`t ask why!

  mgmcc 08:52 01 Nov 2007

ADSL is a technology to provide broadband over conventional phone lines and is used in conjunction with an ADSL Modem or Modem/Router.

From that point on, i.e. the connections from Modem or Modem/Router to PCs, ADSL doesn't come into it, you are running a network with TCP/IP protocols and I suspect your problem may be due to IP addressing within the network.

If you have a combined "ADSL Modem & Router" which is functioning correctly, there is no reason why you cannot connect a stand-alone "Cable/DSL" router (i.e. with no integral Modem) via its WAN port to one of the main Modem/Router's LAN ports. Provided the two routers don't operate in the same Subnet (IP address range), thus causing an IP address conflict, any computers connected to the second router should also have internet access.

Computers connected to the first router and computers connected to the second router won't see each other over the network because they are in different Subnets blocked by the Subnet Mask address.

  Heefie 09:39 01 Nov 2007

OK, thanks mgmcc, I understand what you are saying, but the questions now are (a) can I prove that this is the problem ? (b) how would I do that ? (c) how do I resolve the problem if this is the case ?


All of my PCs are set up to allocate their own IP addresses, would I have to hard code individual addresses into each one ?

  mgmcc 11:53 01 Nov 2007

Connect the PC's network port to one of the second router's LAN ports and connect the second router's WAN port to one of the main Modem/Router's LAN ports.

Power on the main Modem/Router and, when fully booted and online, power on the second Router. When that is running, boot the PC.

The PC should now have an IP address allocated by the second router. If you type the second router's own IP address into your web browser this should open its configuration pages. In its "status" section, you should be able to see the WAN IP address that it has obtained from the main Modem/Router.

  Heefie 13:55 01 Nov 2007

OK, I've done as instructed and can tell you the following, unfortunately I have now got to the limit of my Network knowledge !!!

I entered 192.168.1.1 in the Firefox address line to access the Wireless Router & can tell you the following :

LAN Settings : 192.168.1.1
Subnet Mask : 255.255.255.0

The Router acts as DHCP Server : Enabled
IP Pool Start Address : 192.168.1.2
IP Pool End Address : 192.168.1.254

Routing Table :
Flags Network Address Netmask Gateway Interface Metric
C 127.0.0.1 255.255.255.255 127.0.0.1 Loopback 1
C 224.0.1.134 255.255.255.255 192.168.1.1 Loopback 1
C 192.168.1.0 255.255.255.0 192.168.1.1 Loopback 1
* Flag C = "Directly Connected"

DDNS Service : Disabled

Internet Settings:
PPP over Ethernet Enabled : Yes
Internet IP Address : 0.0.0.0 - PPPoE
Subnet Mask : 0.0.0.0
ISP Gateway Address : 0.0.0.0 - Disconnected
DNS : 0.0.0.0 ; 0.0.0.0

LAN Settings :
LAN IP Address : 192.168.1.1
LAN Subnet Mask : 255.255.255.0
Router's DHCP Server : Enabled
DHCP Range : 192.168.1.2 to 192.168.1.254

I have the following "Network Connections"

1394 Connection - Connected - 1394 Net Adaptet
Obtain IP address automatically
Obtain DNS Server address automatically
DHCP Enabled

Local Area Connection - Connected - Marvell Yukon 88E8001/8003/8010 PCI Gigabit Ethernet controller
Obtain IP address automatically
Obtain DNS Server address automatically
DHCP Enabled

Exactly how these relate to these, I don't know :

C:\>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : Study
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Marvell Yukon 88E8001/8003/8010 PCI Gigabit Ethernet Controller
Physical Address. . . . . . . . . : 00-11-D8-A9-3D-9A
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.110
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 192.168.1.1
Lease Obtained. . . . . . . . . . : 01 November 2007 12:39:26
Lease Expires . . . . . . . . . . : 02 November 2007 00:37:02

I hope this all makes sense ... it doesn't do a lot for me !!!

  mgmcc 07:48 02 Nov 2007

>>> Internet Settings:
>>> PPP over Ethernet Enabled : Yes
>>> Internet IP Address : 0.0.0.0 - PPPoE
>>> Subnet Mask : 0.0.0.0
>>> ISP Gateway Address : 0.0.0.0 - Disconnected
>>> DNS : 0.0.0.0 ; 0.0.0.0

If this is the second router whose WAN port is connected to one of the main router's LAN ports, then it hasn't got its addresses by DHCP from the main router.

It should be set up to get its addresses by DHCP, or for a "direct" connection (depending on the terminology used by the particular router), but you *SHOULDN'T* be using PPPoE protocol. There is no Point-to-Point Protocol used to connect a sub-router to a main router.

  Heefie 09:05 02 Nov 2007

Well, those details come from logging into the second router, yes, the stand-alone wireless router that was plugged into the new modem/router.

I haven't touched a single thing, software-wise, I just left all the settings the same and linked the wireless router in and out of the link, so the settings are all as before when it was attached to a stand-alone 3-com ADSL modem only.

Now, accessing the internet only via the new Modem+Router, without the second router in the loop, if I run IPCONFIG I get the following :

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Administrator>cd..

C:\Documents and Settings>cd..

C:\>ipconfig

Windows IP Configuration


Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
IP Address. . . . . . . . . . . . : 192.168.1.7
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1

... and if I enter 192.168.1.1 into Firefox I am asked for a sign-in and password, so the new modem+router is definitely on the same IP address.

Firstly, the PPPoE is what UTV tells me to use & whhat I've always used, would this need to be changed simply because both of the hardwares are "routers" ?

Secondly, could this be resolved by amending the second router to be 192.168.1.2 or something other than 1.1 & if so, how do I go about that ?!?

  mgmcc 11:36 02 Nov 2007

>>> Firstly, the PPPoE is what UTV tells me to use & what I've always used, would this need to be changed simply because both of the hardwares are "routers"?

UTV may have told you to use PPPoE to connect to their service, but the *SECOND* router isn't connecting to their service, it is connecting only to a router within your Local Area Network - there is therefore no PPP involved.

If the main router's IP address is 192.168.1.1 then you need to set the second router to use a different Subnet. Do this by changing its own IP address so that the *THIRD* octet is different, for example set it to 192.168.2.1 or 192.168.3.1 etc.

  Heefie 22:00 02 Nov 2007

... not sure I'd want you as a teacher though, mgmcc, as you made me work too hard and think for myself (I'm 49, gave all that crap up years ago <s> !!!) ... but everything you said was spot on and all is now working handsomely !!!

Thanks for all your help, you know your stuff ... if commendations are given out, PCA, this man deserves one ... nobody else offered a jot of advice !!!

Gaz

  Taff™ 09:52 05 Nov 2007

That`s because we knew you had the expert on your case ;o)

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