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