Lose Broadband Connection Evertime I Reboot PC

Sleinous

Sleinous

Author Level
What a pain! Ive pretty much run out of stuff to try, will keep trying stuff though as i think of it
 
Gorman

Gorman

Author Level
Hi,

The most likely cause for this in my mind is that you are using a straight through CAT5 cable when ideally there should be a crossover cable / router / hub / switch between the modem and the PC.

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

This would explain these symptoms and probably solve the issue.

Most modern boards can compensate for this but both sides have to play nice, im guessing that there is an occasional negotiation failure giving the on and off connection.

Automatic crossover
The automatic MDI/MDI-X configuration feature eliminates the need for crossover cables, making obsolete the uplink/normal ports and manual selector switches found on many older hubs and switches and greatly reducing installation errors. Note that although Automatic MDI/MDI-X is generally implemented, a crossover cable would still be required in the occasional situation that neither of the connected devices has the feature implemented and enabled.

Although Auto-MDIX is specified as an optional feature in the 1000BASE-T standard[1], in practice it is implemented on all 1000BASE-TX interfaces.

Modern switches automatically apply an internal crossover when necessary. Besides the eventually agreed upon Automatic MDI/MDI-X, this feature may also be referred to by various vendor-specific terms including: Auto uplink and trade, Universal Cable Recognition and Auto Sensing.
Click to expand...
 
W

Wolfie1011

Member
Just wanted to add my two cents. As a computer networks student I have to say that there is a space between ipconfig and the /. It should be ipconfig /release and ipconfig /renew, you can also try ipconfig /flushdns.
 
Gorman

Gorman

Author Level
Red Squirrel said:
Just done as instructed and here are the results...


C:\Windows\system32>ipconfig /release

Windows IP Configuration


Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Link-local IPv6 Address . . . . . : fe80::d837:9d81:d502:6a93%11
Default Gateway . . . . . . . . . :

Tunnel adapter 6TO4 Adapter:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :

Tunnel adapter Local Area Connection* 12:

Connection-specific DNS Suffix . :
IPv6 Address. . . . . . . . . . . : 2001:0:5ef5:79fd:b2:66:add0:de18
Link-local IPv6 Address . . . . . : fe80::b2:66:add0:de18%13
Default Gateway . . . . . . . . . :

Tunnel adapter isatap.cable.virginmedia.net:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :

C:\Windows\system32>ipconfig /renew

Windows IP Configuration


Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : cable.virginmedia.net
Link-local IPv6 Address . . . . . : fe80::d837:9d81:d502:6a93%11
IPv4 Address. . . . . . . . . . . : 82.47.33.281
Subnet Mask . . . . . . . . . . . : 255.255.254.0
Default Gateway . . . . . . . . . : 82.47.32.1

Tunnel adapter 6TO4 Adapter:

Connection-specific DNS Suffix . : cable.virginmedia.net
IPv6 Address. . . . . . . . . . . : 2002:522f:21e7::522f:21e7
Default Gateway . . . . . . . . . :

Tunnel adapter Local Area Connection* 12:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :

Tunnel adapter isatap.cable.virginmedia.net:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : cable.virginmedia.net

C:\Windows\system32>
Click to expand...

This did what it was supposed to and gave a valid Virgin Media IP, nothing wrong there.

Sleinous said:
no space between ipconfig and the / or it wont work and will just display 'ipconfig' command
Click to expand...

You crazy wrong.

Wolfie1011 said:
Just wanted to add my two cents. As a computer networks student I have to say that there is a space between ipconfig and the /. It should be ipconfig /release and ipconfig /renew, you can also try ipconfig /flushdns.
Click to expand...

You right.

But its still the crossover cable thing.
 
W

Wolfie1011

Member
It should be possible to use a standard ethernet cable to connect the computer directly to the modem. A crossover cable is normally used to connect a pc to another pc or in large networks when connecting a switch to another.
 
Gorman

Gorman

Author Level
Wolfie1011 said:
It should be possible to use a standard ethernet cable to connect the computer directly to the modem. A crossover cable is normally used to connect a pc to another pc or in large networks when connecting a switch to another.
Click to expand...

Yes. Thats why i explained, in detail above, that it could be Auto-MDIX playing up.

We have tried one, time to try the other.
 
Sleinous

Sleinous

Author Level
Wolfie1011 said:
Just wanted to add my two cents. As a computer networks student I have to say that there is a space between ipconfig and the /. It should be ipconfig /release and ipconfig /renew, you can also try ipconfig /flushdns.
Click to expand...

Ye was for Vista, not 7, Microsoft cleverly changed the whole thing again -.-

EDIT: Just tried both on this one, neither worked so looks like we're both wrong xD
 
Last edited:
R

Red Squirrel

Bronze Level Poster
Sleinous said:
Lets hope so, and you still occasionally get a connection? Looks like Gorman's hit the nail on the head with this one.
Click to expand...

When i switch the modem and pc on at the same time the pc searches for a connection and it doesn't find one and in the local area connection settings it says 'network cable unplugged'

The only 2 ways i can get a connection is to disable the LAN from network connections and unplug the modem for a minute and switch the modem back on and enable the LAN and then it identifies the modem and connects, the 2nd way to get a connection is boot up the pc with the modem unplugged and once fully booted i plug the modem in and it identifies the modem and gives me a connection.

Thanks to Gorman for his input and fingers crossed he is right!
 
Gorman

Gorman

Author Level
As discussed with Wolfie1011, this is purely a stab in the dark as im presuming a fault with the negotiation between the modem and nic. I hope it works, but there should be no need for a crossover cable here.

If the cable doesnt give the expected result i would strongly recommend a router which should keep the connection alive.
 
Sleinous

Sleinous

Author Level
Sure sounds like it, as, the first method you're using is the equivalent of releasing and renewing ip
 
R

Red Squirrel

Bronze Level Poster
Thanks for the info Wolfie1011

I'm going to wait until I get the cross over ethernet cable and try that 1st before trying the suggestions on the link you provided
 
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