1# 2# hosts.allow access control file for "tcp wrapped" applications. 3# 4# NOTE: The hosts.deny file is deprecated. 5# Place both 'allow' and 'deny' rules in the hosts.allow file. 6# See hosts_options(5) for the format of this file. 7# hosts_access(5) no longer fully applies. 8# 9# _____ _ _ 10# | ____| __ __ __ _ _ __ ___ _ __ | | ___ | | 11# | _| \ \/ / / _` | | '_ ` _ \ | '_ \ | | / _ \ | | 12# | |___ > < | (_| | | | | | | | | |_) | | | | __/ |_| 13# |_____| /_/\_\ \__,_| |_| |_| |_| | .__/ |_| \___| (_) 14# |_| 15# !!! This is an example! You will need to modify it for your specific 16# !!! requirements! 17 18 19# Start by allowing everything (this prevents the rest of the file 20# from working, so remove it when you need protection). 21# The rules here work on a "First match wins" basis. 22ALL : ALL : allow 23 24# Wrapping sshd(8) is not normally a good idea, but if you 25# need to do it, here's how 26#sshd : .evil.cracker.example.com : deny 27 28# Protect against simple DNS spoofing attacks by checking that the 29# forward and reverse records for the remote host match. If a mismatch 30# occurs, access is denied, and any positive ident response within 31# 20 seconds is logged. No protection is afforded against DNS poisoning, 32# IP spoofing or more complicated attacks. Hosts with no reverse DNS 33# pass this rule. 34ALL : PARANOID : RFC931 20 : deny 35 36# Allow anything from localhost. Note that an IP address (not a host 37# name) *MUST* be specified for rpcbind(8). 38ALL : localhost 127.0.0.1 : allow 39# Comment out next line if you build libwrap without IPv6 support. 40ALL : [::1] : allow 41#ALL : my.machine.example.com 192.0.2.35 : allow 42 43# To use IPv6 addresses you must enclose them in []'s 44#ALL : [fe80::%fxp0]/10 : allow 45#ALL : [fe80::]/10 : deny 46#ALL : [2001:db8:2:1:2:3:4:3fe1] : deny 47#ALL : [2001:db8:2:1::]/64 : allow 48 49# Sendmail can help protect you against spammers and relay-rapers 50sendmail : localhost : allow 51#sendmail : .nice.guy.example.com : allow 52#sendmail : .evil.cracker.example.com : deny 53sendmail : ALL : allow 54 55# Exim is an alternative to sendmail, available in the ports tree 56exim : localhost : allow 57#exim : .nice.guy.example.com : allow 58#exim : .evil.cracker.example.com : deny 59exim : ALL : allow 60 61# Rpcbind is used for all RPC services; protect your NFS! 62# Rpcbind should be running with -W option to support this. 63# (IP addresses rather than hostnames *MUST* be used here) 64#rpcbind : 192.0.2.32/255.255.255.224 : allow 65#rpcbind : 192.0.2.96/255.255.255.224 : allow 66rpcbind : ALL : deny 67 68# NIS master server. Only local nets should have access 69# (Since this is an RPC service, rpcbind needs to be considered) 70ypserv : localhost : allow 71#ypserv : .unsafe.my.net.example.com : deny 72#ypserv : .my.net.example.com : allow 73ypserv : ALL : deny 74 75# Provide a small amount of protection for ftpd 76ftpd : localhost : allow 77#ftpd : .nice.guy.example.com : allow 78#ftpd : .evil.cracker.example.com : deny 79ftpd : ALL : allow 80 81# You need to be clever with finger; do _not_ backfinger!! You can easily 82# start a "finger war". 83fingerd : ALL \ 84 : spawn (echo Finger. | \ 85 /usr/bin/mail -s "tcpd\: %u@%h[%a] fingered me!" root) & \ 86 : deny 87 88# The rest of the daemons are protected. 89ALL : ALL \ 90 : severity auth.info \ 91 : twist /bin/echo "You are not welcome to use %d from %h." 92