Date: Tue, 11 Feb 2003 22:38:06 -0600 From: Redmond Militante <r-militante@northwestern.edu> To: freebsd-questions@freebsd.org Subject: portsentry in combination with ipfilter Message-ID: <20030212043806.GA1267@darkpossum>
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--GvXjxJ+pjyke8COw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable hi all i have an ipf/ipnat gateway machine protecting an internal network of - so= far one, hopefully 2 or more - computers. the first thing i did after i observed that i have my setup successfully n= at'ing, was to try to portscan myself from an outside machine, using nmap. at first i thought something was up, and that my ipf.rules were being igno= red, because when i ran =20 nmap -sS -v -O=20 on my the public ip of my internal host - which was aliased to the externa= l nic of my gateway box - it showed that a huge amount of tcp and udp ports= were open. i could copy the nmap results, but they're long, and suffice it= to say ports i thought were closed or inactive were shown as open. =20 after discussing it with the -security listserv, and running a 'sockstat' = on the gateway box, it turns out that portsentry was indeed listening on th= e great majority of ports that the nmap showed to be open. when i turn port= sentry off and run nmap again on my setup, it only shows ports that i speci= ally allow open in my ipf/ipnat rules like 80,22, etc. =20 my question is: first if anyone knows how to get portsentry to not broadca= st the fact that it's listening on a wide variety ports when the host is be= ing portscanned. i checked the portsentry.conf file, there didn't seem to b= e an option for this. also - i have =20 block return-rst in log quick on xl0 proto tcp from any to any =20 in my ipf.rules, so i thought that any ports not be nat'd would show up in= portscans as not listening. not sure why this isn't working. =20 also, i had wanted to run logcheck, portsentry, and snort or tripwire on m= y ipf/ipnat gateway box. is this a good combination of apps? as of now, i h= ave portsentry turned off, but would like to use it or an app that performs= the same function. =20 any thoughts? =20 thanks again redmond --GvXjxJ+pjyke8COw Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (FreeBSD) iD8DBQE+Sc+uFNjun16SvHYRAqXaAJ99tM0EzKiHEJAoei9VXRoy1XXUqwCgqgbc BhWJlLD6DA9W7ovzoxPLxh8= =5h7L -----END PGP SIGNATURE----- --GvXjxJ+pjyke8COw-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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