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Wrong. |
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1) If you don't receive "destination unreachable" packet, you know |
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nothing about the target host yet. This is not perfect-network world. |
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There can be other fw/router anywhere in the way, killing this type of |
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icmp traffic. |
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2) It slows scans a lot. You can of course do scannig in parallel, but |
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don't be surprised, when you find yourself killed with no mercy by IDS, |
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after matching SYN threshold. 1000+ syns/sec form IP adress to monitored |
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system is sure ban. |
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Daniel Privratsky |
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Oliver Schad wrote: |
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> Am Mittwoch, 7. Januar 2004 23:05 schrieb mir Mark Hurst: |
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> |
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>>It's much better to have a firewall than just have ports not open. Even |
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>>though a port is not open it can reveal the presence of your machine by |
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>>the manner in which the IP stack responds to a connection attempt. |
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>>Using a firewall you can drop those packets, making all your closed |
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>>ports invisible. |
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> |
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> |
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> If you want to invisible, the next router to you have to send an ICMP |
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> packet with "host unreachable". If you say nothing anybody with some |
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> brain between his ears knows there is a very intelligent guy that want to |
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> be invisible. |
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> |
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> mfg |
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> Oli |
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> |
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> -- |
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> gentoo-security@g.o mailing list |
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> |
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> |
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-- |
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gentoo-security@g.o mailing list |
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