Security Basics mailing list archives

Re: Reflexive firewalls?


From: Gustavo Castro <gcastrop () gmail com>
Date: Tue, 27 Jan 2009 16:14:46 -0200

Guys:

  Looks a lot like a really primitive "port-knocking" authentication method...
  http://www.portknocking.org/

2009/1/27 mgk.mailing <mgk.mailing () googlemail com>:
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hi

That sound like the user-auth feature on juniper firewalls, you telnet /
http to the target and once authenticated it allows you to ssh etc as
per rules setup.  Its not great but a useful tool, as it opens up the
policy to all at the source address of the successfully authenticated user.

/Mgk

Ong Chin Kiat wrote:
Hi list,

I've recently used an SSH server that had an interesting authentication
mechanism. You first had to telnet to the machine on a certain port.
After doing this (it will just time out - no prompt), you then SSH to
the server in question. The telnet step has to be carried out, if not
SSH will just time out.

My question is, is this called reflexive firewalling, and can I
duplicate this with iptables?

Thanks.
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-- 
Saludos,
     Gustavo Castro Puig.
     E-Mail: gcastrop () gmail com

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