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Strange Networking problem

FIXED IT...

... but I cannot understand why it worked!

Jack by the hedge said:
Just to clarify, when assigned its fixed IP address, the new computer could not ping 1,1,1,1?
Click to expand...

Correct


Jack by the hedge said:
And when DHCP gave it another IP address, the other computers on the network could not communicate with it by its computer name, but they could by its IP address?
Click to expand...

Correct.

And this together with the results from doing a tracert as suggested by a_unique_person got me to thinking - if tracert 192.168.1.65 got me the result: "Tracing route to PHOTOLAB-2 [192.168.1.65]", then tracert Photolab-2 ought to have got me "Tracing route to [192.168.1.65] PHOTOLAB-2". Yes? But instead, it got me "Unable to resolve target system name PHOTOLAB-2"

So, what if the problem is something to do with the name itself? Not the actual name per se, but perhaps using a name that had been used previously, on a different computer, was causing a problem on the whole network.

I set the IPV4 settings on Photolab-2 to allow DHCP to choose the IP address, went into THIS PC settings and changed the computer name to DESKTOP1 and restarted the the computer. Once it restarted, I did IP config to find its address (192.168.1.11).

- I checked to make sure it could connect to the internet - yup!

- I tried accessing it from another computer using \\192.168.1.11 - yup!

- I tried accessing it from another computer using \\DESKTOP1 - YUP!!!!:thumbsup:

Now, I tried changing the IPV4 settings to fixed 192.168.1.65 and rechecked..
Internet :thumbsup:
Access via IP address :thumbsup:
Access via computer name :thumbsup:

I then created a System Restore point because I wanted to get back to this state if the next thing I did crapped it out.

I changed the computer name back to Photolab-2 and restarted.
Internet :thumbsup:
Access via fixed IP address :thumbsup:
Access via computer name :thumbsup:

I really do not understand why this worked. AFAIK it should not make any difference what the computer name was - perhaps changing it cleared or reset something that the other steps did not reset. But it works now exactly as it did before.
 
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Thank you to everyone who contributed to the thread and gave helpful suggestions as to what I could try next. Some of them did point me towards the solution.
 
So the old DNS name was cached somewhere...

I wonder where?

Probably we should have tried the ipconfig /flushdns on one of the machines that couldn't connect.

My guess is that it would have been in your router and changing the computer name forced it to update its IP tables.
 
novaphile said:
So the old DNS name was cached somewhere...

I wonder where?

Probably we should have tried the ipconfig /flushdns on one of the machines that couldn't connect.
My guess is that it would have been in your router and changing the computer name forced it to update its IP tables.
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Hmm, I checked the Mac tables and the IP numbers. I'm not aware of seeing anything in the router that looked like a table of names. I'm pretty sure the NetGear router does not have a DHCP client list.
 
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smartcooky said:
Hmm, I checked the Mac tables and the IP numbers. I'm not aware of seeing anything in the router that looked like a table of names. I'm pretty sure the NetGear router does not have a DHCP client list.
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But do you know for certain that it does not? I think the router can have a built in DCHP server and ISTR having a problem when there were two on my LAN.
 
Gord_in_Toronto said:
But do you know for certain that it does not? I think the router can have a built in DCHP server and ISTR having a problem when there were two on my LAN.
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What I mean is, there is no table that is accessible to the user. Some routers I know do have a tables that literally list the mac numbers, associated IP addresses and associated computer names in columns. Mine only lists the first two.
 
Probably has to do with the WINS name resolution. Changing the computer name forces a re-broadcast of WINS names, otherwise it would probably have started working on its own after the 3-day WINS cache expired.
 
theprestige said:
The worst part of IT troubleshooting is end-users getting pissy when you start with the basics because you have no idea what they've already tried or what the results were.

"Trust that I've already tried the obvious stuff. What else could be going wrong?" is a terrible strategy for getting tech support.
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Quite.

It wasn’t obvious to me why there was no connectivity to the internet. Usually it’s either a routing problem or a name service problem. You need to know which.

Pinging a name rather than an IP address, for example, is useless if you haven’t established that you can ping the IP address directly first.

OTOH if you are using hosts files to get the local names, it’s pretty obvious aDHCP supplied address is going to be a problem because every time it changes you need to change all of the hosts files.
 
theprestige said:
The worst part of IT troubleshooting is end-users getting pissy when you start with the basics because you have no idea what they've already tried or what the results were.

"Trust that I've already tried the obvious stuff. What else could be going wrong?" is a terrible strategy for getting tech support.
Click to expand...

I first heard the phrase "When you've tried absolutely everything and nothing works, check it's plugged in and switched on" many years ago from a PhD student who ran university physics labs. In my 4 decades of IT I have seen really experienced capable people make the silliest of mistakes, myself included. Also many numpties who thought they knew what they were doing.
 
Wudang said:
I first heard the phrase "When you've tried absolutely everything and nothing works, check it's plugged in and switched on" many years ago from a PhD student who ran university physics labs. In my 4 decades of IT I have seen really experienced capable people make the silliest of mistakes, myself included. Also many numpties who thought they knew what they were doing.
Click to expand...

I've sorta/kinda seen it.

For people that are very good at their job, but just treat computers as an appliance.

I've mentioned before the relatively senior person, who didn't realise that a computer needed to be connected to the network, in order to access things over the network.

It was pointed out to me, that so many devices now, don't require a network cable, (phones, tablets, laptops) and that it would be easy for a person to not realise that desktop computers don't work that way, depending on what they've been exposed to up to now.

Note that in corporate environments, users don't get to look inside the box, and often are locked out of any admin functionality, so they just rely on the thing, provided by someone else, to do its job.

I do have friends and family members now who have desktop computers that connect to the network by wifi, so it's probably not far away that this will be the standard.

(Similarly desktop computers that support bluetooth.)

Hell, now that I think of it, I have elements in my hifi stack that are capable of wireless networking.
 
Just acquired my first PC tower with wifi. It was an included feature in the model I wanted, and there was no option to remove it for a price reduction.

My employers have been laptop-with-wifi exclusively, for my job function, for about a decade now.
 
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