Annoying router connection issue

**The Wikir Man** · 16 April 2010, 10:37

Have you tried setting the pc to pick up the dns and IP address dynamically?

What is the dns setting for the network connection?

**Sysman** · 16 April 2010, 10:42

Originally posted by meridian View Post

Checked ipconfig on pc. It's auto-setting the ip address to 169.x.x.x, subnet 250.250.0.0.

I can answer the 169.x.x.x bit.

169.254.0.0 to 169.254.255.255

From RFC 3330

"169.254.0.0/16 - This is the "link local" block. It is allocated for
communication between hosts on a single link. Hosts obtain these
addresses by auto-configuration, such as when a DHCP server may not be found."

My laptop comed up with that if I start it with DHCP enabled but no cable plugged in and wireless switched off.

**VectraMan** · 16 April 2010, 10:45

Are you using a crossover rather than patch cables? Most things auto detect these days, but maybe your PC doesn't.

Do the lights come on on the router and PC card to show there's a connection?

**pmeswani** · 16 April 2010, 11:39

Originally posted by meridian View Post

Grrrr! Normally get these things to work, but this one has me stumped.

On an intended home network I have:
An Acer pc running Vista Home. All updates installed.
A Dell laptop running XP
A Netgear wnr2000v2 wireless router
A Cisco EPV2203 cable modem

The required configuration is for the pc to connect via ethernet to the router, which connects via ethernet to the modem, which is connected to the interweb. The laptop is to connect wirelessly to the router.

- Cabled the laptop to the router to the modem to the internet. Opened router admin at 192.168.1.1 and configured the SSID and security. Tested internet connection and all works okay.

- Unplugged laptop and connected wirelessly. Everything still works okay, laptop can connect to router admin and can surf the net.

- Cabled pc into router. Doesn't see it at all. Doesn't ping, nothing on 192.168.1.1.

- Tested pc ethernet jack by plugging the cable directly into the modem. PC connects to the internet fine when going direct through modem, all working there.

- Reconnected pc to router. Still doesn't see it. Swapped cables over. Still nada. Laptop happily connects to internet wirelessly through router still.

Checked ipconfig on pc. It's auto-setting the ip address to 169.x.x.x, subnet 250.250.0.0. Manually set TCP/IP for ipv4 to set ip address as 192.168.1.10, subnet 255.255.255.0, gateway 192.168.1.1. Ipv6 is still obtained automatically.

Rebooted pc, it now shows an ethernet connection to the router but has "Limited or no connectivity". Ipconfig shows the address as 192.168.1.10, but still can't access the router.

Unchecked Ipv6, rebooted. Same thing.

Got me stumped. Why the heck would the pc be able to connect fine to the modem, but just not see the router at all?

I assume you have tried ipconfig /renew and arp -a

Have you also checked your network card speed settings is set to Automatic or the same / lower speed to that of your router?

I also assume that your laptop is still able to surf the interweb.

**meridian** · 16 April 2010, 12:03

Originally posted by The Wikir Man View Post

Have you tried setting the pc to pick up the dns and IP address dynamically?

What is the dns setting for the network connection?

Yep. When on Automatic and with ethernet to router connected the address is 169.254.x.x, subnet mask 255.255.0.0, default gateway empty. When Auto and connected direct to modem it's 80.x.x.x, 255.255.252.0, 80.x.x.x.

DNS setting is auto.

Originally posted by Sysman View Post

I can answer the 169.x.x.x bit.

169.254.0.0 to 169.254.255.255

From RFC 3330

"169.254.0.0/16 - This is the "link local" block. It is allocated for
communication between hosts on a single link. Hosts obtain these
addresses by auto-configuration, such as when a DHCP server may not be found."

My laptop comed up with that if I start it with DHCP enabled but no cable plugged in and wireless switched off.

Still could be either a network card issue or a router issue. That's why I'm a bit confused at the mo - the network card works fine when connected direct to the modem, and the router works fine when the laptop is connected by cable.

Originally posted by VectraMan View Post

Are you using a crossover rather than patch cables? Most things auto detect these days, but maybe your PC doesn't.

Do the lights come on on the router and PC card to show there's a connection?

The cables came with the boxes. I assume they're straight, the 5 year old Dell has no problems but the 1 year old Asus does. Mind you, it's Asus...

Lights are on on both router and pc.

Originally posted by pmeswani View Post

I assume you have tried ipconfig /renew and arp -a

Have you also checked your network card speed settings is set to Automatic or the same / lower speed to that of your router?

I also assume that your laptop is still able to surf the interweb.

ipconfig /renew fails - when ip address is static the message is "no adapter is in the state permissible for this operation"; when auto, the message is "unable to contact dhcp server"

Network card is 10/100, router is supposed to be 300.

Laptop can still surf the web, both wirelessly and ethernet through the router.

**pmeswani** · 16 April 2010, 12:25

Originally posted by meridian View Post

ipconfig /renew fails - when ip address is static the message is "no adapter is in the state permissible for this operation"; when auto, the message is "unable to contact dhcp server"

Network card is 10/100, router is supposed to be 300.

Laptop can still surf the web, both wirelessly and ethernet through the router.

I've never known a router to work at 300 before. If plugging the desktop straight into the modem (over ethernet) works, then it could be the speed setting on the network interface on the router.

**doodab** · 16 April 2010, 13:36

300 refers to the wireless speed, I suspect the wired ports are still 10/100.

The 80.x.x.x address is the one assigned by the cable company, I don't know about these days but they used to require you register the MAC address of whatever you are connecting to the modem, so that might be an issue.

Do both PCs pick up an address and see the router if you disconnect the router from the modem?

What address does the laptop get?

When you connect the router to the modem and it's working, what does the router report as the WAN IP address?

**VectraMan** · 16 April 2010, 13:56

Originally posted by doodab View Post

I don't know about these days but they used to require you register the MAC address of whatever you are connecting to the modem, so that might be an issue.

IIRC some PPPoE routers (i.e for cable) let you manually set a MAC address to get around this problem. If the router was using the same MAC address as your PC, that would explain everything that was happening.

Have a good look through the router settings for anything about MAC addresses.

**NickFitz** · 16 April 2010, 19:52

When you set up security, did you by any chance set a restriction on the MAC addresses of devices that are allowed to connect?

Annoying router connection issue