said by neam :
I have been probing my internet connection for holes and noticed Ports 135,139, and 445 showed closed instead of stealth when running shields up test from the grc website. I would like for these ports to be "stealth" like they always have been in the past. My router firewall is locked down in stealth mode. Even tried a different router. Tried static and DHCP on my LAN made no difference. I also forwarded these ports to non-existing ip addresses (in static mode) on my lan and it still fails. I've had at&t dsl (dynamic IP) for a long time and my internet connection always came back stealth before. I have not made any changes and use the same equipment that tested stealth before. Can at&t's equipment be responding to these ports? I have called tech support and they say that this issue is beyond their scope.
What brand/model of modem and/or router do you use? Can you post detailed information of exactly how they are configured and connected? How is you PC configured and connected? Do you use a VPN or proxy?
There are too many variables for anyone to be able to answer your question. However, I can safely say that I have never run across a residential/soho grade NAT router that had RPC, NBT, and SMB ports exposed to the Internet by default (although a closed port is not really exposing anything since there is no server to respond). My best wild guess (assuming that you did not manually create firewall rules to expose those ports) is that your router has UPnP enabled, and some application or attached device has used that unlocked backdoor entry point to expose those ports.
Post some screen shots of your modem/router/PC firewall config/rules and someone can probably explain the problem to you. If you would like a second opinion on your RPC, NBT, and SMB port status on the Internet, feel free to go to »portscan.dcs-net.net
and select the port scan test.--
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