How Do I fix My TCP problem?

Question

Since yesterday afternoon I have been having problems accessing some websites. I can ping them and they answer, but I can't surf over to the site. Some sites I have no problem with, yet others simply won't download. I tried doing a system restore to take me back to 4 days before as i had added a port for a program on Friday, but had no problems. My ISP can't figure it out either, except thinks it possible I have a worm, but I scan clean. I can access on dialup with no problem, its just with the dsl that I have the problem. I do have a router with a network to my laptop.

Answer 1

Are you trying to surf to the sites by name or by IP address?

If you're trying to do it by name, try the following:
ping the name.
you should get the IP address back
surf to the ip address.

If that works you've got a name resolution issue... your PC has forgotten how to look up some names in IE. Ping and IE use slightly different name resolution methods, so sometimes one will work and the other won't. It may mean your DNS servers have got messed up for your DSL connection (like for instance your dial-up ones got hard coded in). The fact it works on diaup means it's not something inherently broke in your PC.

If you can only get to some sites *even* using the IP address have you got a firewall on your PC and is it doing content filtering / site name filtering? Someone may have put something wierd into your firewall rules designed to protect children from inappropriate sites. That's what happened to my father ( a visitor messed about and changed the rulesfor him).

Answer 2

I cannot be sure, but it is beginning to sound like a NAT problem in the router? (Network Address Translation).

My suggestion would be to get your setting checked thoroughly by your ISP, but you have already done that!

Being able to access them on dial-up is VERY useful! It eliminates so many possibilities.

Since you can get there on dial-up, I should say it is definitely NOT a virus, or Trojan, or worm - Nor is it your browser, or it's settings. It's just my opinion, but I would have thought that any of these would have prevented you from accessing them on dial-up as well.

To me, it seems like a DSL/router/ISP problem. Stick with it if you can and try and work with your ISP to isolate what could be causing this problem. I hope you manage to track it down without too many more problems!

I am assuming it was all working well beforehand though? Have you tried uninstalling the program you added a port for as well? If all was working fine, try to think what else had recently been done to the computer before the problem showed up? I've had updated sound card programs prevent my modem from connecting. Similar, but not quite the same as those you are having...

Good luck!!!

Answer 3

See if you can BYPASS the router and connect to the DSL modem directly. It is possible that your router has gone bad. So then, BUY a new Router.

Be sure to run a full anti-virus scan. You should have an anti-spyware solution on your computer. I recommend that you go to http://www.download.com and get AD-AWARE and SpyBot Search & Destory. Install, run, update and scan your computer with both programs.

These are cleanup tools. Ad-aware cleans files, and SpyBot cleans the registry

Good luck and Happy Computing!

Answer 4

This sounds like either a DNS problem, or a hijacker!

1) Open a command prompt window and enter the command:
IPCONFIG /ALL
and check the DNS values with your ISP to see if they are valid...

2) Check the HOSTS file on your machine to see if it has been hijacked.. This has a list of sites that will not use DNS and bypass lookup.

3) Also try using HIJACKTHIS to diagnose hijackers...
See the reference below for more info on these tools...

Answer 5

Clear up your internet files and your history and see if that works.