AnonymouseUser
Diamond Member
- May 14, 2003
- 9,943
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So the router is defaulting to 192.168.100.X, but you are manually changing the range in the router config to 192.168.1.X, and it still assigns 192.168.100.X?
Yeah, that's the part that's driving me crazy and has been happening with all 3 routers i've tried. I thought it was a problem with the cable modem and some DNS conflicts, but even with the cable modem unplugged the routers are still assigning incorrect IP addresses.
Would changing the routers default IP address to 192.168.100.2 and then assigning IP addresses from 192.168.100.3 - 192.168.100.254 possible solve this problem?
All the configs on my router are set to assign IP's on the 192.168.1.1 subnet but none of them seem to be doing that and my computers will only work with static IP's assigned to them
Would changing the routers default IP address to 192.168.100.2 and then assigning IP addresses from 192.168.100.3 - 192.168.100.254 possible solve this problem?
All the configs on my router are set to assign IP's on the 192.168.1.1 subnet but none of them seem to be doing that and my computers will only work with static IP's assigned to them
AnonymouseUser
Diamond Member
- May 14, 2003
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It's very odd if all three refuse to assign the subnet you are configuring them to. As MontyAC suggested, try another subnet and see if that works. If it doesn't, then I'm out of suggestions.
jibs have you tried making this as simple as you can by just having one computer plugged into one router without the modem and having the wireless disabled on the router? Eliminate the switch as well. It just seems like there is a rogue DHCP server somewhere handing out those 192.168.100.x addresses to your computers.
If you do this simple test and the one computer still gets an IP address on the wrong subnet then the problem has to be in your client computers. Either TCP/IP in them is messed up or there is some kind of malware causing this.
If you do this simple test and the one computer still gets an IP address on the wrong subnet then the problem has to be in your client computers. Either TCP/IP in them is messed up or there is some kind of malware causing this.
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Plugging my laptop directly into the cable modem gets me an IP address of 174.0.xxx.xxx which I believe is my WAN address.
Plugging my cable modem into my router and plugging my laptop into the router gets me an IP address of 192.168.100.xxx.
Changing the IP address on the router to 192.168.0.1 and rebooting it, I was still being assigned IP's in the 192.168.100.xxx range.
Changing the IP on the router to 192.168.100.1 and rebooting it I was assigned the proper 192.168.100.xxx IP address but I was unable to access the internet. I think there is a conflict using this IP range since the Default IP for the cable modem is 192.168.100.1.
Changing the IP on the router to 192.168.200.1 and rebooting I was still assigned an IP address in the range 192.168.100.xxx.
To try and rule out a virus/malware issue I have tried connecting with 2 windows computers, a linux laptop and an imac and all of them are having the same problems.
There are a few settings in my routers configuration that I have played with, I'm going to post screenshots so you can see my config and let me know if there is anything I should change. These settings work using a static IP on all of my computers, but do not work when I let the computers auto assign IP's
Plugging my cable modem into my router and plugging my laptop into the router gets me an IP address of 192.168.100.xxx.
Changing the IP address on the router to 192.168.0.1 and rebooting it, I was still being assigned IP's in the 192.168.100.xxx range.
Changing the IP on the router to 192.168.100.1 and rebooting it I was assigned the proper 192.168.100.xxx IP address but I was unable to access the internet. I think there is a conflict using this IP range since the Default IP for the cable modem is 192.168.100.1.
Changing the IP on the router to 192.168.200.1 and rebooting I was still assigned an IP address in the range 192.168.100.xxx.
To try and rule out a virus/malware issue I have tried connecting with 2 windows computers, a linux laptop and an imac and all of them are having the same problems.
There are a few settings in my routers configuration that I have played with, I'm going to post screenshots so you can see my config and let me know if there is anything I should change. These settings work using a static IP on all of my computers, but do not work when I let the computers auto assign IP's
- Oct 25, 1999
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First step is to use wire and isolate units.
As an example take the new Router and one computer off the Network.
Connect the computer with a wire to one of the Router's port and try to configure and make sure that indeed the Router has the required subnet and the computer is stable at the correct IP.
Then take every thing of the Modem and connect to it only the new Router and the one wired computer. If it works start to add other Network components one at the time until you will find what brakes the system.
Otherwise, given the 3 weeks long story it might be time to spend few $$ and bring in a Network pro.
As an example take the new Router and one computer off the Network.
Connect the computer with a wire to one of the Router's port and try to configure and make sure that indeed the Router has the required subnet and the computer is stable at the correct IP.
Then take every thing of the Modem and connect to it only the new Router and the one wired computer. If it works start to add other Network components one at the time until you will find what brakes the system.
Otherwise, given the 3 weeks long story it might be time to spend few $$ and bring in a Network pro.
I haven't read through this entire thread. But you don't have the DHCP server on your router configured to assign DNS configuration to your clients. If your router can handle DNS (most SOHO routers do), then enter 192.168.1.1 as the DNS server on the DHCP server configuration page.
Changing the IP of your router won't change the address range that DHCP users. But I'm not sure why you're messing with that anyway. You want your router and all of your clients on the 192.168.1.0/24 network (ip addresses of 192.168.1.1 through 192.168.1.254 with subnet mask 255.255.255.0).
Also, I think your router and cable modem are both acting as DHCP servers, and they're both performing NAT (this is only based on the information from your last post...like I said, I haven't read through the entire thread). You probably only want to have one of them doing that.
Can you give a TL;DR summary of this thread?
Changing the IP of your router won't change the address range that DHCP users. But I'm not sure why you're messing with that anyway. You want your router and all of your clients on the 192.168.1.0/24 network (ip addresses of 192.168.1.1 through 192.168.1.254 with subnet mask 255.255.255.0).
Also, I think your router and cable modem are both acting as DHCP servers, and they're both performing NAT (this is only based on the information from your last post...like I said, I haven't read through the entire thread). You probably only want to have one of them doing that.
Can you give a TL;DR summary of this thread?
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Seepy83, basically I have a cable modem from my ISP, plugged into my wireless router (192.168.1.1) and my computers plugged into the router. My router is set to assign IP's in the starting with 192.168.1.xxx. If I leave all my computers set to obtain IP's automatically they're getting assigned IP's of 192.168.100.xxx and cannot connect to the internet. If I set static IP's on my computers of 192.168.1.xxx then everything works properly. I have tried 3 different wireless routers and i'm having the same problem with all of them.
I just spoke with my ISP and they have finally agreed to replace my cable modem, since I wasn't having this problem before we moved to a new city using the same wireless router and computer configurations.
I just spoke with my ISP and they have finally agreed to replace my cable modem, since I wasn't having this problem before we moved to a new city using the same wireless router and computer configurations.
I looked through the thread quickly...It doesn't look like you ever posted an ipconfig /all from when your computer was connected to the router with DHCP enabled and received an IP on the wrong subnet (192.168.100.0/24 instead of 192.168.1.0/24). If you run ipconfig /all when that happens, it will tell you what DHCP server was used to configure the connection.
If it says that 192.168.1.1 assigned you an address of 192.168.100.xxx, then your router is the problem. Either it's not configured correctly, or the firmware is garbage and it either needs to be reflashed or thrown away.
If it says DHCP was assigned by something other than 192.168.1.1, it would help to know what the address is and what host has that address, because it would mean that you have a second DHCP server on the same network segment.
If it says that 192.168.1.1 assigned you an address of 192.168.100.xxx, then your router is the problem. Either it's not configured correctly, or the firmware is garbage and it either needs to be reflashed or thrown away.
If it says DHCP was assigned by something other than 192.168.1.1, it would help to know what the address is and what host has that address, because it would mean that you have a second DHCP server on the same network segment.
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Here is the ipconfig -all from my laptop, assigned the wrong IP address, plugged into the wireless router.
C:\Users\Brett>ipconfig -all
Windows IP Configuration
Host Name . . . . . . . . . . . . : Laptop
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Wireless LAN adapter Wireless Network Connection 2:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Virtual WiFi Miniport Adapter
Physical Address. . . . . . . . . : 00-21-6A-9A-22-97
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Wireless LAN adapter Wireless Network Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) WiFi Link 5300 AGN
Physical Address. . . . . . . . . : 00-21-6A-9A-22-96
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Ethernet adapter Bluetooth Network Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
Physical Address. . . . . . . . . : 0C-60-76-8B-34-50
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82567LM Gigabit Network Connecti
on
Physical Address. . . . . . . . . : 00-27-13-66-20-94
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::f1cf:2d6b:ffa5:2e0e%10(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.100.13(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Sunday, March 03, 2013 11:47:24 PM
Lease Expires . . . . . . . . . . : Sunday, March 03, 2013 11:48:10 PM
Default Gateway . . . . . . . . . : 192.168.100.1
DHCP Server . . . . . . . . . . . : 192.168.100.1
DHCPv6 IAID . . . . . . . . . . . : 234891027
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-16-8A-6C-63-00-27-13-66-20-94
DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
fec0:0:0:ffff::2%1
fec0:0:0:ffff::3%1
NetBIOS over Tcpip. . . . . . . . : Enabled
Tunnel adapter isatap.{A9F7479C-662D-4D43-A5CC-CF34FE1FB6D2}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Teredo Tunneling Pseudo-Interface:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
[FONT="] Autoconfiguration Enabled . . . . : Yes[/FONT]
192.168.100.1 I believe the cable modem login page, there is a screenshot of it in post #16
C:\Users\Brett>ipconfig -all
Windows IP Configuration
Host Name . . . . . . . . . . . . : Laptop
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Wireless LAN adapter Wireless Network Connection 2:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Virtual WiFi Miniport Adapter
Physical Address. . . . . . . . . : 00-21-6A-9A-22-97
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Wireless LAN adapter Wireless Network Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) WiFi Link 5300 AGN
Physical Address. . . . . . . . . : 00-21-6A-9A-22-96
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Ethernet adapter Bluetooth Network Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
Physical Address. . . . . . . . . : 0C-60-76-8B-34-50
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82567LM Gigabit Network Connecti
on
Physical Address. . . . . . . . . : 00-27-13-66-20-94
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::f1cf:2d6b:ffa5:2e0e%10(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.100.13(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Sunday, March 03, 2013 11:47:24 PM
Lease Expires . . . . . . . . . . : Sunday, March 03, 2013 11:48:10 PM
Default Gateway . . . . . . . . . : 192.168.100.1
DHCP Server . . . . . . . . . . . : 192.168.100.1
DHCPv6 IAID . . . . . . . . . . . : 234891027
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-16-8A-6C-63-00-27-13-66-20-94
DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
fec0:0:0:ffff::2%1
fec0:0:0:ffff::3%1
NetBIOS over Tcpip. . . . . . . . : Enabled
Tunnel adapter isatap.{A9F7479C-662D-4D43-A5CC-CF34FE1FB6D2}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Teredo Tunneling Pseudo-Interface:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
[FONT="] Autoconfiguration Enabled . . . . : Yes[/FONT]
192.168.100.1 I believe the cable modem login page, there is a screenshot of it in post #16
AnonymouseUser
Diamond Member
- May 14, 2003
- 9,943
- 107
- 106
OK, so it looks like your router isn't responding to DHCP requests. And your router is forwarding that broadcast out its WAN port where it's being answered by your cable modem. Honestly, it sounds like your router is bricked. But you can try disabling the DHCP server on it and then enable it again (thinking the running configuration on it might not actually have the DHCP server running even though the web management interface is showing it configured).
Does the same thing happen when you don't have the cable modem connected to your router?
Does the same thing happen when you don't have the cable modem connected to your router?
So this morning I plugged my work laptop into my switch and it was assigned a proper IP address. I came home from work and did the same thing and it was assigned an incorrect 192.168.100.1 IP address. On the wireless router I turned off some settings, turned them back on, rebooted the router and now my computers are being assigned correct IP's. Here is an ipconfig -all from my laptop:
C:\Users\Brett>ipconfig -all
Windows IP Configuration
Host Name . . . . . . . . . . . . : Laptop
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82567LM Gigabit Network Connecti
on
Physical Address. . . . . . . . . : 00-27-13-66-20-94
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Wireless LAN adapter Wireless Network Connection 2:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Virtual WiFi Miniport Adapter
Physical Address. . . . . . . . . : 00-21-6A-9A-22-97
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Wireless LAN adapter Wireless Network Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) WiFi Link 5300 AGN
Physical Address. . . . . . . . . : 00-21-6A-9A-22-96
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::9d06:63a1:bfcc:439b%14(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.23(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 184557930
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-18-C7-71-21-00-21-6A-9A-22-96
DNS Servers . . . . . . . . . . . : 208.67.222.222
208.67.220.220
NetBIOS over Tcpip. . . . . . . . : Enabled
Ethernet adapter Bluetooth Network Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
Physical Address. . . . . . . . . : 0C-60-76-8B-34-50
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter isatap.{A0185453-CF59-4195-B892-1FFFADEF5B65}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Teredo Tunneling Pseudo-Interface:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:9d38:953c:3003:1d8b:bb6f:d524(Pref
erred)
Link-local IPv6 Address . . . . . : fe80::3003:1d8b:bb6f:d524%12(Preferred)
Default Gateway . . . . . . . . . : ::
[FONT="] NetBIOS over Tcpip. . . . . . . . : Disabled[/FONT]
I don't really understand why it is working now, I'm definitely going to keep an eye on it for the next few days and see if anything changes.
Thanks for all the help on this
C:\Users\Brett>ipconfig -all
Windows IP Configuration
Host Name . . . . . . . . . . . . : Laptop
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82567LM Gigabit Network Connecti
on
Physical Address. . . . . . . . . : 00-27-13-66-20-94
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Wireless LAN adapter Wireless Network Connection 2:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Virtual WiFi Miniport Adapter
Physical Address. . . . . . . . . : 00-21-6A-9A-22-97
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Wireless LAN adapter Wireless Network Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) WiFi Link 5300 AGN
Physical Address. . . . . . . . . : 00-21-6A-9A-22-96
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::9d06:63a1:bfcc:439b%14(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.23(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 184557930
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-18-C7-71-21-00-21-6A-9A-22-96
DNS Servers . . . . . . . . . . . : 208.67.222.222
208.67.220.220
NetBIOS over Tcpip. . . . . . . . : Enabled
Ethernet adapter Bluetooth Network Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
Physical Address. . . . . . . . . : 0C-60-76-8B-34-50
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter isatap.{A0185453-CF59-4195-B892-1FFFADEF5B65}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Teredo Tunneling Pseudo-Interface:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:9d38:953c:3003:1d8b:bb6f:d524(Pref
erred)
Link-local IPv6 Address . . . . . : fe80::3003:1d8b:bb6f:d524%12(Preferred)
Default Gateway . . . . . . . . . : ::
[FONT="] NetBIOS over Tcpip. . . . . . . . : Disabled[/FONT]
I don't really understand why it is working now, I'm definitely going to keep an eye on it for the next few days and see if anything changes.
Thanks for all the help on this
jibs did you notice that the laptop is connecting to the router *wirelessly*? This is from your most recent ipconfig post. Did you expect the laptop to be connected by wire instead? Also, if you notice the wireless in your laptop isn't using DHCP.
Thanks for pointing that out, I hadn't noticed it, I guess between changing router settings and trying to troubleshoot connection problems on 2 laptops I missed a setting. Yeah this is definitely not working.
Have you tried connecting a single machine wired to the router without the modem or the switch connected to see if it gets the correct IP address? Have the wireless in the router turned off as well.
In other words, one machine plugged directly into the router with absolutely NOTHING else. No wireless enabled in the router, no modem, no switch. You could also reset the router back to factory defaults first to be absolutely sure.
If this doesn't work the problem HAS to be in the machine and you can start troubleshooting that. If it does work you can go to the next step and add the modem to get Internet access for the one machine, but please report back on the test of just the one machine and router first.
In other words, one machine plugged directly into the router with absolutely NOTHING else. No wireless enabled in the router, no modem, no switch. You could also reset the router back to factory defaults first to be absolutely sure.
If this doesn't work the problem HAS to be in the machine and you can start troubleshooting that. If it does work you can go to the next step and add the modem to get Internet access for the one machine, but please report back on the test of just the one machine and router first.
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VirtualLarry
No Lifer
- Aug 25, 2001
- 56,587
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My ISP is sending me a new cable modem to see if that helps the problem, I don't think it will but it's the only piece of equipment I haven't replaced. A co-worker gave me a program to check for rogue dhcp servers on your network. I ran it last night and it showed that 192.168.100.1 and 192.168.1.1 were both acting as dhcp servers. If I turn of the dhcp services on my wireless router I was having a problem assigning usable IP addresses. I'm going to play around with this tonight to see if I can figure it out. Does anyone know if you can have your ISP disable dhcp from their end???
My ISP is sending me a wireless router in Bridge mode so i'm still able to use my wireless router if I would like to.
I'm going to look into their wireless router and if it can do the port forwarding I need it to do then I might just take my router out of the picture and do everything on their router.
I will update once I have it all setup again.
My ISP is sending me a wireless router in Bridge mode so i'm still able to use my wireless router if I would like to.
I'm going to look into their wireless router and if it can do the port forwarding I need it to do then I might just take my router out of the picture and do everything on their router.
I will update once I have it all setup again.
Good idea running the check for rouge DHCP servers. There is your problem, just as I suspected from the start. The question now is just finding where the 2nd DHCP server on 192.168.100.1 is.
You shouldn't need to have your ISP do anything on their end. Even if their modem is acting as a DHCP server your client machines won't see it, assuming you have the modem plugged into the Internet port on your router and NOT your switch or the built-in switch on your router?
You still haven't done the test I wanted you to do where you connect a single machine directly to your router with the wireless disabled and NOTHING else connected. If you're still getting the wrong IP address the only possibility I see is some kind of malware in your computers that's acting as a DHCP server.
You shouldn't need to have your ISP do anything on their end. Even if their modem is acting as a DHCP server your client machines won't see it, assuming you have the modem plugged into the Internet port on your router and NOT your switch or the built-in switch on your router?
You still haven't done the test I wanted you to do where you connect a single machine directly to your router with the wireless disabled and NOTHING else connected. If you're still getting the wrong IP address the only possibility I see is some kind of malware in your computers that's acting as a DHCP server.
Sorry I got busy last night and this slipped my mind. I will give it a try tonight and let you know the results. Thanks for the help
Alright, the new cable modem from my ISP showed up. Now before I connected everything I unplugged everything from my wireless router, disabled the wifi and connected my laptop to 1 of the LAN ports. I was assigned the proper 192.168.1.xxx IP address automatically. I ran the rogue dhcp server software and it only shows 1 dhcp server, 192.168.1.1 which is my wireless router.
I plugged in my new cable modem, let it load, plugged it into the WAN port on my wireless router, connected my laptop and was assigned a 192.168.100.xxx IP address. I ran the rouge dhcp software and it's showing 2 dhcp servers, 192.168.1.1 and 192.168.100.1. When I point my browser to 192.168.100.1 it takes me to the admin page for my new cable modem, the Cisco dpc3825.
The Cisco dpc3825 is a wireless modem that my ISP has put in bridge mode. I tried to login to the modem but all my login attempts are rejected. After doing some reading online I found that if the modem is bridged you aren't able to log in. The modem is also not broadcasting a wifi signal which leads me to believe that it is in fact in bridge mode.
I guess we've determined what is causing the problem, now I'm wondering how I go about fixing it? Looking at some screenshots of the Cisco modem admin pages, it looks like it has most of the features I need to setup my network properly so I could have it put back into normal mode and use it as a modem and wireless router. Although there are not a lot of positive reviews out there for the unit as a router, most people suggest getting it bridged and using your own wireless router.
I plugged in my new cable modem, let it load, plugged it into the WAN port on my wireless router, connected my laptop and was assigned a 192.168.100.xxx IP address. I ran the rouge dhcp software and it's showing 2 dhcp servers, 192.168.1.1 and 192.168.100.1. When I point my browser to 192.168.100.1 it takes me to the admin page for my new cable modem, the Cisco dpc3825.
The Cisco dpc3825 is a wireless modem that my ISP has put in bridge mode. I tried to login to the modem but all my login attempts are rejected. After doing some reading online I found that if the modem is bridged you aren't able to log in. The modem is also not broadcasting a wifi signal which leads me to believe that it is in fact in bridge mode.
I guess we've determined what is causing the problem, now I'm wondering how I go about fixing it? Looking at some screenshots of the Cisco modem admin pages, it looks like it has most of the features I need to setup my network properly so I could have it put back into normal mode and use it as a modem and wireless router. Although there are not a lot of positive reviews out there for the unit as a router, most people suggest getting it bridged and using your own wireless router.
The problem is that your router is forwarding DHCP request broadcasts out its WAN port instead of the internal DHCP server on your router answering those requests.
You have two networks.
The LAN side of your router is the 192.168.1.0/24 network. DHCP requests on that network segment should be answered by the DHCP server in the router at 192.168.1.1. The router should not be forwarding those DHCP broadcasts out the WAN port.
The WAN side of your router is the 192.168.100.0/24 network. When your router has the cable modem connected to the WAN port, it is forwarding the DHCP broadcasts to that network instead of responding to them.
Your router is the problem. It is not working the way it should (at least based on my experience with typical SOHO routers). Either there is a setting in your router for DHCP relay and it's enabled, or the router's firmware is bad.
Replace your router, or borrow a router from a friend and see if it fixes it.
You have two networks.
The LAN side of your router is the 192.168.1.0/24 network. DHCP requests on that network segment should be answered by the DHCP server in the router at 192.168.1.1. The router should not be forwarding those DHCP broadcasts out the WAN port.
The WAN side of your router is the 192.168.100.0/24 network. When your router has the cable modem connected to the WAN port, it is forwarding the DHCP broadcasts to that network instead of responding to them.
Your router is the problem. It is not working the way it should (at least based on my experience with typical SOHO routers). Either there is a setting in your router for DHCP relay and it's enabled, or the router's firmware is bad.
Replace your router, or borrow a router from a friend and see if it fixes it.
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