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We have a Windows XP SP3 computer that a coworker previously blocked outgoing internet activity on. Now we are trying to restore it, but the coworker can't seem to remember how he did it. Some amount of local connectivity remains, as it is able to reach our network attached storage and our point of sale program is able to connect to its SQL database. However, it is not able to connect to our local IM server (jabber protocol, I believe using port 5222) and it is not able to connect to the routers web interface (or any other http page). Through testing I've found that it is:

  • Not blocked locally through a firewall

  • Not blocked by any access controls in the switch or router that I can find

  • Not blocked locally by an IPSEC policy (or at least netdiag.exe /test:ipsec states that no ipsec policies are defined).

  • Not accomplished by redirecting using a proxy (or at least none are defined in internet options)

  • Not accomplished by altering the hosts file in /system32/drivers/etc

  • Not dependent on the local IP address

  • Seemingly not dependent on Mac address (or at least not resolved by moving the network cable to the other port; I suppose both addresses may be blocked somewhere)

Does anyone have any suggestions on how else internet activity may have been blocked?

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Can you ping the addresses? – soandos Jun 14 '12 at 0:23
up vote 1 down vote accepted

You could...

  • boot to a Linux LiveCD like Linux Mint or even Parted Magic. Why? Well, if the machine is blocked at the router or by it's MAC Addresses (it has two network adapters?) then you could prove this by removing the installed OS and trying another. A LiveCD offers you this ability without actually deleting anything. Why those two choices? Well, for one, Linux Mint has great hardware support out the gate.... and I just like Parted Magic.

  • reinstall Windows. Yes, I know. Simplistic, and not very imaginative.... but hey, almost every computer could benefit from having it's OS reinstalled every once in a while. Ok. Maybe not every computer... but computers that had people monkeying around with the settings could benefit from this, especially when the person doing the monkeying can't retrace his or her own steps.

  • use a program like ComboFix or Spybot Search & Destroy to look for system changes/additions that you may have missed or that he may have made/added.

share|improve this answer
Thanks for the suggestions. Ha, I've been meaning to try out Mint anyway since Ubuntu switched to the Unity shell. This does seem like as good an opportunity as any. I also hadn't thought of using a virus scan to check for system changes, but it makes since. I hope I can avoid the nuclear option of a total os reinstall, but we'll see what it comes to. – Spencer Jun 14 '12 at 0:21
@Spencer the AV/anti-malware option was more for how ComboFix will reset system settings back to defaults in a ton of places, and how Spybot can clear out/set up a hosts file automatically. I know you already checked that, but it does look for connectivity issues as well... to a degree. – Bon Gart Jun 14 '12 at 0:23

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