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vbrindle
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Why are certain ports closed

Some ports are blocked as indicated in this article:
https://www.virginmedia.com/help/virgin-media-blocked-internet-ports

My question is why are they closed rather than stealth?

If you run the port scan at grc.com all ports are showing stealth apart from the ones blocked by virgin media. Connections being refused shows the hacker that it exists so will probe further.

I'm getting reports of dropped packets from Russian IP's on my router.

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DJ_Shadow1966
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Re: Why are certain ports closed

Hello

The ports in that webpage are blocked as they should not be used on the internet, they really are only for internal network use, that webpage does tell you why.

A "Stealth" port is one that completely ignores and simply "drops" any ... "Closed" is the best you can hope for without a stealth firewall or NAT router in place. The hubs have a stealth firewall, which will just drop the packets that try to use them it doesn't send a signal back to the host, where a closed port will respond back to the host that it is closed.

Regards Mike

 

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vbrindle
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Re: Why are certain ports closed

Hi,

Yes, I know this, so if the hub uses stealth then why do those ports show as closed, surely those ports should be stealthed.

To me the response to say it's closed tells the attacker there's something there.

I'm using my own firewall btw which is stealth but because Virgin Media are blocking the ports they are being marked as closed rather than stealth.

In my logs I'm getting traffic from Russia which isn't good at all....

Thanks

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用心棒
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Re: Why are certain ports closed


@vbrindle wrote:

To me the response to say it's closed tells the attacker there's something there.


I'm using my own firewall btw which is stealth but because Virgin Media are blocking the ports they are being marked as closed rather than stealth.

No, the miscreant has no more confidence of there being a device at that IP Address than if the packet was dropped; Virgin Media's network level firewall is unlikely to be checking if the IP Address is allocated before denying the traffic.

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DJ_Shadow1966
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Re: Why are certain ports closed

Hello

The technology  used on the end which VM uses to do port filtering doesn't use a Stealth firewall and if you look around you will also find that Stealth ports are not a part of the standard of networking.

Regards Mike

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