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On Wednesday 27 February 2008, Remy Blank wrote: |
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> Steve wrote: |
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> > I'm one of the (many) people who has opportunists trying usernames |
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> > and passwords against SSH... while every effort has been made to |
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> > secure this service by configuration; strong passwords; no root |
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> > login remotely etc. I would still prefer to block sites using |
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> > obvious dictionary attacks against me. |
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> |
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> The best advice I can give is to use public key authentication only. |
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> This will defend against all dictionary-based attacks, which is what |
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> you describe. |
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> |
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> The only remaining "problem" is that your log files will be filled |
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> with unsuccessful login attempts. A simple solution is to run sshd on |
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> a non-standard, high-numbered port, e.g. in the 30'000. Bots only ever |
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> try to connect on port 22. This will *not* improve the protection of |
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> your server, but it will avoid having your logs spammed. |
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Agreed. For me, changing the port SSH listens on alone eliminated 99% of |
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brute force attempts. |
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I also agree on public key authentication. Depending on the OP's needs |
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and context), he might also be interested in portknocking (no flames |
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please :-)). |
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-- |
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