1# 2# hosts.allow access control file for "tcp wrapped" applications. 3# $FreeBSD: src/etc/hosts.allow,v 1.8.2.7 2002/04/17 19:44:22 dougb Exp $ 4# $DragonFly: src/etc/hosts.allow,v 1.4 2008/08/10 21:29:16 hasso Exp $ 5# 6# NOTE: The hosts.deny file is deprecated. 7# Place both 'allow' and 'deny' rules in the hosts.allow file. 8# See hosts_options(5) for the format of this file. 9# hosts_access(5) no longer fully applies. 10 11# _____ _ _ 12# | ____| __ __ __ _ _ __ ___ _ __ | | ___ | | 13# | _| \ \/ / / _` | | '_ ` _ \ | '_ \ | | / _ \ | | 14# | |___ > < | (_| | | | | | | | | |_) | | | | __/ |_| 15# |_____| /_/\_\ \__,_| |_| |_| |_| | .__/ |_| \___| (_) 16# |_| 17# !!! This is an example! You will need to modify it for your specific 18# !!! requirements! 19 20 21# Start by allowing everything (this prevents the rest of the file 22# from working, so remove it when you need protection). 23# The rules here work on a "First match wins" basis. 24ALL : ALL : allow 25 26# Wrapping sshd(8) is not normally a good idea, but if you 27# need to do it, here's how 28#sshd : .evil.cracker.example.com : deny 29 30# Protect against simple DNS spoofing attacks by checking that the 31# forward and reverse records for the remote host match. If a mismatch 32# occurs, access is denied, and any positive ident response within 33# 20 seconds is logged. No protection is afforded against DNS poisoning, 34# IP spoofing or more complicated attacks. Hosts with no reverse DNS 35# pass this rule. 36ALL : PARANOID : RFC931 20 : deny 37 38# Allow anything from localhost. Note that an IP address (not a host 39# name) *MUST* be specified for portmap(8). 40ALL : localhost 127.0.0.1 : allow 41ALL : my.machine.example.com 192.0.2.35 : allow 42 43# To use IPv6 addresses you must enclose them in []'s 44ALL : [fe80::%fxp0]/10 : allow 45ALL : [fe80::]/10 : deny 46ALL : [2001:db8:2:1:2:3:4:3fe1] : deny 47ALL : [2001:db8:2:1::]/64 : allow 48 49# Sendmail can help protect you against spammers and relay-rapers 50sendmail : localhost : allow 51sendmail : .nice.guy.example.com : allow 52sendmail : .evil.cracker.example.com : deny 53sendmail : ALL : allow 54 55# Exim is an alternative to sendmail, available in the pkgsrc tree 56exim : localhost : allow 57exim : .nice.guy.example.com : allow 58exim : .evil.cracker.example.com : deny 59exim : ALL : allow 60 61# Portmapper is used for all RPC services; protect your NFS! 62# (IP addresses rather than hostnames *MUST* be used here) 63portmap : 192.0.2.32/255.255.255.224 : allow 64portmap : 192.0.2.96/255.255.255.224 : allow 65portmap : ALL : deny 66 67# Provide a small amount of protection for ftpd 68ftpd : localhost : allow 69ftpd : .nice.guy.example.com : allow 70ftpd : .evil.cracker.example.com : deny 71ftpd : ALL : allow 72 73# You need to be clever with finger; do _not_ backfinger!! You can easily 74# start a "finger war". 75fingerd : ALL \ 76 : spawn (echo Finger. | \ 77 /usr/bin/mail -s "tcpd\: %u@%h[%a] fingered me!" root) & \ 78 : deny 79 80# The rest of the daemons are protected. 81ALL : ALL \ 82 : severity auth.info \ 83 : twist /bin/echo "You are not welcome to use %d from %h." 84