Simple TCP/IP connectivity test

I've created a simple tool to test two TCP/IP addresses to see if they can communicate on the same network. It can be found here:

TCP/IP connection tester

Hopefully it will allow people who have a basic connectivity problem to check that their IP addresses are compatible, without them having to post their addresses on this board.

It is a first attempt. If people find it useful, I can add functionality to do things like check gateway settings and perhaps replicate ping tests. Part of the reason I've done this is as a little project to help me learn JavaScript, so the code has room for improvement (error catching for example).

Please feel free to have a play!

 

Nice piece of work. I like it and it seems easy enough to use. Love to see some other folks (maybe non-networking folks) try it.

The top section probably isn't what you intended though - at least as rendered on my browser.

 

Hey ReggieB...

I echo Newts comments...nice piece of work. I also see the what Newt saw on the top section of my browser.

 

Thanks for the comments. I'm testing with Mozilla. Seems like IE isn't seeing the style sheet the same way. I'll work on that once I got the functionality right.

I'm currently working on an update - I realised that the tool doesn't handle partial subnets (for example, if you use a mask or 255.255.255.128). I'm closed to getting that licked.

 

Well, you'll be glad to know that after a couple more hours working on it, I've now got a version that works the way I want it to, does some entry validation and now handles awkward subnets correctly ..... except one thing. Works a treat on Firefox 0.9. Won't work at all in IE 6. Ahhhhhhhh!!!!!!!

I'll have to get another text book from work and work though it to spot the problem.

For those of you interested, latest version is here.

 

Kewl...I don't see the extra code anymore ReggieB...thanks.

 

Success

I've finally tracked down the problem that was stopping the JavaScript working in IE. It was a comma in the wrong place!!!!!

However, I've updated the original file so the tool is now working!!!! It still looks better in Firefox (I'm still failing to get IE to talk to the style sheet properly), but the functionality is the same in both browsers.

New features are data validation (warnings now appear if you put in an obviously wrong entry), and the system now treats partial subnets correctly.

There is still room for improvement. Next update will recognise classes, I think. Also want to add some gateway options.

Please feel free to try the new version of .

TCP/IP connectivity checker

 

sweet dude. fun with javascript

Think i found a bug for you to chase down

Code:

Computer 1 
IP address is 24.1.1.1/255.255.248.0
Subnet is 24.1.0.0
Node Number is 255.255.249.1
Computer 2 
IP address is 24.1.9.1/255.255.248.0
Subnet is 24.1.0.0
Node Number is 255.255.249.1
Both computers belong to the same subnet 
Both computers have the same node number. This will cause a conflict when they are on the same subnet. Try changing the last octet of Computer 2's IP address from 1 to 2
The subnet masks match 
-------------------------------------------------
Computer 1 
IP address is 24.1.1.1/255.255.255.248
Subnet is 24.1.1.0
Node Number is 255.255.255.249
Computer 2 
IP address is 24.1.1.16/255.255.255.248
Subnet is 24.1.1.0
Node Number is 255.255.255.248
Both computers belong to the same subnet 
The Nodes Numbers are different, which is correct. 
The subnet masks match 
 

 

Thanks JoeHobart.

I thought there may be problems with class A and B subnet masks. I think I will need to redesign a little. At the moment comparisons are done at the octet level. I need to combine them and do binary comparisons on the whole address. Should be fairly easy to fix - he said hopefully.

I am also not happy with the way the system is calculating node numbers. Your first example demonstrates the weakness in the current system.

 

OK - Think I've got it cracked.

Sorted out the appearance in IE. The appearance is right, except the red text when an error is found (you'll have to use Firefox to see that!).

I think I've fixed the non 255/0 subnet problems. The system now passes JoeHobart's tests. I've also simplified the coding and added comments.

I've also improved the way node numbers are calculated and the way broadcast addresses are recognised and reported.

And what's more I've added Class recognition. Less because classes are important (they aren't very important nowadays), but more to identify use of illegal or poor Class choice.

The Node2NodeV2.html has been deleted. Just the live version left:

http://www.nicholshayes.co.uk/Node2Node.html

 

Excellent. Nice to see simplicity win out!

Have used it a dozen times already.

 

OK - I think it is finally where I want it now:

The addressing tool in all its glory!

I've split the tool into two versions. A new one which allows you to add Gateway addresses, and the original one that just works with IP addresses and masks. Both version now have data validation (that is they check to see if the values entered are between 0 and 255 before processing).

I've made two versions as I think the gateway address may just add complication for some people who just want to check their basic addressing, while others might find the gateway element useful.

I've also created a front page that gives you links to the two tools and some useful links for basic networking information. The link above takes you to this front page.

As always, any comments welcome.