Internet connection issue

[LocalHero]

Greetings

I have an intermittent problem connecting to the internet from one
computer in my home network.

My main computer is a Win 7 Pro machine, hard-wired to my router. I
also have another PC hardwired, a laptop connected by wi-fi, and my
smartphone also uses the wi-fi connection.

At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still connects.

This can happen at every bootup, or sometimes it doesnt happen for
weeks on end, or sometimes it happens every couple of days - it's
totally random.

When it happens, sometimes a simple reboot fixes it, but sometimes
several reboots are needed, and sometimes, after several reboots
without success I have switched the router off and back on, and then
restarted the PC, and that always seems to work.


So - any ideas on what I should do to troubleshoot?

Thanks


--

 

[richard]

Greetings

I have an intermittent problem connecting to the internet from one
computer in my home network.

My main computer is a Win 7 Pro machine, hard-wired to my router. I
also have another PC hardwired, a laptop connected by wi-fi, and my
smartphone also uses the wi-fi connection.

At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still connects.

This can happen at every bootup, or sometimes it doesnt happen for
weeks on end, or sometimes it happens every couple of days - it's
totally random.

When it happens, sometimes a simple reboot fixes it, but sometimes
several reboots are needed, and sometimes, after several reboots
without success I have switched the router off and back on, and then
restarted the PC, and that always seems to work.


So - any ideas on what I should do to troubleshoot?

Thanks

double check your IP assignments and see if there are any conflicts.

could be you set one of the other machines the same as your main one.

 

[GlowingBlueMist]

Greetings

I have an intermittent problem connecting to the internet from one
computer in my home network.

My main computer is a Win 7 Pro machine, hard-wired to my router. I
also have another PC hardwired, a laptop connected by wi-fi, and my
smartphone also uses the wi-fi connection.

At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still connects.

This can happen at every bootup, or sometimes it doesnt happen for
weeks on end, or sometimes it happens every couple of days - it's
totally random.

When it happens, sometimes a simple reboot fixes it, but sometimes
several reboots are needed, and sometimes, after several reboots
without success I have switched the router off and back on, and then
restarted the PC, and that always seems to work.


So - any ideas on what I should do to troubleshoot?

Thanks

Try another cable between the affected computer and the router.

Vibration on a partially bad cable, like a bad connection on one of the
wires, could cause what you describe. When you reboot or power reset
the router/computer possibly just enough vibration is created that
makes/breaks the defective connection.

 

[Big Steel]

Greetings

I have an intermittent problem connecting to the internet from one
computer in my home network.

My main computer is a Win 7 Pro machine, hard-wired to my router. I
also have another PC hardwired, a laptop connected by wi-fi, and my
smartphone also uses the wi-fi connection.

At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still connects.

This can happen at every bootup, or sometimes it doesnt happen for
weeks on end, or sometimes it happens every couple of days - it's
totally random.

When it happens, sometimes a simple reboot fixes it, but sometimes
several reboots are needed, and sometimes, after several reboots
without success I have switched the router off and back on, and then
restarted the PC, and that always seems to work.


So - any ideas on what I should do to troubleshoot?

Thanks

Hard reset the router or flash the router with its firmware to see if
that corrects the problem. By doing either procedure, the settings you
had for the router will need to be done again.

 

[Paul]

Greetings

I have an intermittent problem connecting to the internet from one
computer in my home network.

My main computer is a Win 7 Pro machine, hard-wired to my router. I
also have another PC hardwired, a laptop connected by wi-fi, and my
smartphone also uses the wi-fi connection.

At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still connects.

This can happen at every bootup, or sometimes it doesnt happen for
weeks on end, or sometimes it happens every couple of days - it's
totally random.

When it happens, sometimes a simple reboot fixes it, but sometimes
several reboots are needed, and sometimes, after several reboots
without success I have switched the router off and back on, and then
restarted the PC, and that always seems to work.


So - any ideas on what I should do to troubleshoot?

Thanks

Some OSes have a "connection troubleshooter". You
can try that. I don't keep track of all the options there.

A typical home setup, the router uses DHCP. That's Dynamic Host
Control Protocol, and part of the job there, is dynamically
assigning an IP address to the PC at startup. You set a
base address and span for the addresses, when configuring
the server.

DHCP address: 192.168.1.79
Number of addresses: 7

When the computer starts, the router doles out an address.
It would be in the range 192.168.1.79 to 192.168.1.85 in
my example. If the number of addresses is set too low,
the router might not have an address to give out.

The wired and wireless might be on separate subnets.

To check your IP address, in a Command Prompt window (cmd.exe)
you can try "ipconfig" as a command. If an address in the
range 192.168.1.79... is visible (i.e. the value matches
what was set in the router configuration page), then it's
probably working at the moment. If you have more
computers than "Number of addresses", then the router
can run out. Post the value of ipconfig, if it's a goofy
value. 10.0.0.x and 192.168.x.x are non-routable (for home
usage on LAN, behind NAT), while the computer itself
will select 169.254.x.x if it can't get an address
from somewhere else.

Another failure, a more likely failure, would be DNS.
You're not really disconnected from the Internet, just
the ability to translate a symbolic to numeric value
is broken.

For example

nslookup www.sun.com

would return say 137.254.16.113.

Now, in your web browser, on a given day, say you try:

http://www.sun.com

and it doesn't work. As a test, you next try

http://137.254.16.113

If the web page appears (or part of it), you know
that the manual address translation done here, worked.
As long as the site doesn't change that IP address,
we can continue to use that as a test case. Your
computer consults a DNS server, to translate
www.sun.com, into the 137.254.16.113 that it really
needs to contact the site.

If the second form works, and the first doesn't, then
in the Command Prompt window, the "nslookup" command is
going to fail too. It might mean the router was not
given a pair of DNS server addresses to use for DNS translation.

On my old ISP, they used to change the DNS assignment regularly.
Then, the dopey bastards would *reboot* the DNS machines,
both of them in the redundant pair, at the same time. And
it might take 15 minutes before they'd reappear. The new
ISP isn't quite as "rich" as the old one, and only has
the one DNS setup and that has never dropped out on me.
Whereas the old ISP had a "fleet" of DNS servers, and
used to treat them like footballs (always booting them).
The old ISP wasn't smart enough to just reboot one of
the two DNS servers in a redundant pair, and wait for the
reboot on the first to finish, before rebooting the second
machine. I guess that's just too easy.

Before we had browsers, another test case would have
been to open a Command Prompt, and

ping 137.254.16.113

But on the Internet now, not every server supports ping.
The ICMP feature that supports it is turned off on a lot
of machines. So it may be easier to use a web browser
and use web servers for checking the plumbing.

Those are some simple tests I use on my computers here.

But in the case of the more modern OSes, they're now getting
to the point, of offering a troubleshooter in the OS, that
does a lot of these tests for you. And such a tool
could potentially tell you the nature of the problem.

It's probably not an electrical problem - unless like
me, you rolled some heavy furniture across one of
your cables :-(

Paul

 

[Char Jackson]

On my old ISP, they used to change the DNS assignment regularly.
Then, the dopey bastards would *reboot* the DNS machines,
both of them in the redundant pair, at the same time. And
it might take 15 minutes before they'd reappear. The new
ISP isn't quite as "rich" as the old one, and only has
the one DNS setup and that has never dropped out on me.
Whereas the old ISP had a "fleet" of DNS servers, and
used to treat them like footballs (always booting them).
The old ISP wasn't smart enough to just reboot one of
the two DNS servers in a redundant pair, and wait for the
reboot on the first to finish, before rebooting the second
machine. I guess that's just too easy.

It's that kind of crap that prompted me to stop using my ISP's DNS
servers about a dozen years ago.

 

[SC Tom]

It's that kind of crap that prompted me to stop using my ISP's DNS
servers about a dozen years ago.

Who do you like? I've been using Google for a short while, and it seems more
stable than my ISP (recently changed from Charter to Hargray since Hargray
bought them out in this area). I don't know if it's Hargray trying to
integrate Charter's equipment and people into their system (been going on
for a few months now), but their connections are sometimes intermittent at
best. Since using Google for DNS, I haven't seen any problems.

 

[Wolf K]

Greetings [...]
At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still connects.

[...]
[snip Paul's cure]

If Paul's cure works, it implies a diagnosis: the router's settings were
messed up. Case solved.

OTOH, if there's a hardware fault in either the computer or the router,
diagnosis is a little tricky. I'd borrow a know working router: if
issues persist, the computer's at fault. If they disappear, the original
router's at fault.

On the given data, I'd bet on a fault in the computer, because the other
machines connect without issues. Could be the network card, or an
outdated driver. Network card drivers do occasionally need updating.

HTH

 

[SC Tom]

Greetings [...]
At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still connects.

[...]
[snip Paul's cure]

If Paul's cure works, it implies a diagnosis: the router's settings were
messed up. Case solved.

OTOH, if there's a hardware fault in either the computer or the router,
diagnosis is a little tricky. I'd borrow a know working router: if issues
persist, the computer's at fault. If they disappear, the original router's
at fault.

Or just swap cable connections with one of the ports that's known to be good

 

[Char Jackson]

Who do you like? I've been using Google for a short while, and it seems more
stable than my ISP (recently changed from Charter to Hargray since Hargray
bought them out in this area). I don't know if it's Hargray trying to
integrate Charter's equipment and people into their system (been going on
for a few months now), but their connections are sometimes intermittent at
best. Since using Google for DNS, I haven't seen any problems.

I've been using Google (8.8.8.8) as my primary for a couple of years
or however long it's been since they put it out there, and Level 3
(4.2.2.1 or 4.2.2.2 or 4.2.2.3) as my secondary.

I occasionally run either Namebench or DNSbench, two small utilities
that check lots of DNS servers to see which are fastest for me, in my
neck of the woods. Google usually comes out on top here, but it may be
different for everyone else. My ISP's DNS servers usually rank pretty
high, but the final straw was when they implemented a spammy landing
page for mistyped and bad domains, rather than simply returning a 404.

<http://code.google.com/p/namebench/>
<http://www.grc.com/dns/benchmark.htm>

 

[LocalHero]

Greetings

I have an intermittent problem connecting to the internet from one
computer in my home network.

My main computer is a Win 7 Pro machine, hard-wired to my router. I
also have another PC hardwired, a laptop connected by wi-fi, and my
smartphone also uses the wi-fi connection.

At random times, when I turn the main computer on, it fails to connect
to the internet. At those times, all the other equipment still
connects.

This can happen at every bootup, or sometimes it doesnt happen for
weeks on end, or sometimes it happens every couple of days - it's
totally random.

When it happens, sometimes a simple reboot fixes it, but sometimes
several reboots are needed, and sometimes, after several reboots
without success I have switched the router off and back on, and then
restarted the PC, and that always seems to work.


So - any ideas on what I should do to troubleshoot?

Thanks

Thanks for the replies - will start digesting and testing asap.


--

 

[Michael]

"GlowingBlueMist" wrote in message

Greetings

I have an intermittent problem connecting to the internet from one
computer in my home network.

My main computer is a Win 7 Pro machine, hard-wired to my router. I
also have another PC hardwired, a laptop connected by wi-fi, and my
smartphone also uses the wi-fi connection.

At random times, when I turn the main computer on, it fails to
connect
to the internet. At those times, all the other equipment still
connects.

This can happen at every bootup, or sometimes it doesnt happen for
weeks on end, or sometimes it happens every couple of days - it's
totally random.

When it happens, sometimes a simple reboot fixes it, but sometimes
several reboots are needed, and sometimes, after several reboots
without success I have switched the router off and back on, and then
restarted the PC, and that always seems to work.


So - any ideas on what I should do to troubleshoot?

Thanks


Try another cable between the affected computer and the router.

Good call - I had the same problem until I accidentally moved the
cable and BINGO!

 

[John Ferrell]

Nice answer Paul,
I will keep this one for my notes!

John de W8CCW

Some OSes have a "connection troubleshooter". You
can try that. I don't keep track of all the options there.

A typical home setup, the router uses DHCP. That's Dynamic Host
Control Protocol, and part of the job there, is dynamically
assigning an IP address to the PC at startup. You set a
base address and span for the addresses, when configuring
the server.

DHCP address: 192.168.1.79
Number of addresses: 7

When the computer starts, the router doles out an address.
It would be in the range 192.168.1.79 to 192.168.1.85 in
my example. If the number of addresses is set too low,
the router might not have an address to give out.

The wired and wireless might be on separate subnets.

To check your IP address, in a Command Prompt window (cmd.exe)
you can try "ipconfig" as a command. If an address in the
range 192.168.1.79... is visible (i.e. the value matches
what was set in the router configuration page), then it's
probably working at the moment. If you have more
computers than "Number of addresses", then the router
can run out. Post the value of ipconfig, if it's a goofy
value. 10.0.0.x and 192.168.x.x are non-routable (for home
usage on LAN, behind NAT), while the computer itself
will select 169.254.x.x if it can't get an address
from somewhere else.

Another failure, a more likely failure, would be DNS.
You're not really disconnected from the Internet, just
the ability to translate a symbolic to numeric value
is broken.

For example

nslookup www.sun.com

would return say 137.254.16.113.

Now, in your web browser, on a given day, say you try:

http://www.sun.com

and it doesn't work. As a test, you next try

http://137.254.16.113

If the web page appears (or part of it), you know
that the manual address translation done here, worked.
As long as the site doesn't change that IP address,
we can continue to use that as a test case. Your
computer consults a DNS server, to translate
www.sun.com, into the 137.254.16.113 that it really
needs to contact the site.

If the second form works, and the first doesn't, then
in the Command Prompt window, the "nslookup" command is
going to fail too. It might mean the router was not
given a pair of DNS server addresses to use for DNS translation.

On my old ISP, they used to change the DNS assignment regularly.
Then, the dopey bastards would *reboot* the DNS machines,
both of them in the redundant pair, at the same time. And
it might take 15 minutes before they'd reappear. The new
ISP isn't quite as "rich" as the old one, and only has
the one DNS setup and that has never dropped out on me.
Whereas the old ISP had a "fleet" of DNS servers, and
used to treat them like footballs (always booting them).
The old ISP wasn't smart enough to just reboot one of
the two DNS servers in a redundant pair, and wait for the
reboot on the first to finish, before rebooting the second
machine. I guess that's just too easy.

Before we had browsers, another test case would have
been to open a Command Prompt, and

ping 137.254.16.113

But on the Internet now, not every server supports ping.
The ICMP feature that supports it is turned off on a lot
of machines. So it may be easier to use a web browser
and use web servers for checking the plumbing.

Those are some simple tests I use on my computers here.

But in the case of the more modern OSes, they're now getting
to the point, of offering a troubleshooter in the OS, that
does a lot of these tests for you. And such a tool
could potentially tell you the nature of the problem.

It's probably not an electrical problem - unless like
me, you rolled some heavy furniture across one of
your cables :-(

Paul

John Ferrell W8CCW