2 # hosts.allow access control file for "tcp wrapped" applications.
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.
11 # | ____| __ __ __ _ _ __ ___ _ __ | | ___ | |
12 # | _| \ \/ / / _` | | '_ ` _ \ | '_ \ | | / _ \ | |
13 # | |___ > < | (_| | | | | | | | | |_) | | | | __/ |_|
14 # |_____| /_/\_\ \__,_| |_| |_| |_| | .__/ |_| \___| (_)
16 # !!! This is an example! You will need to modify it for your specific
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.
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
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
35 ALL : PARANOID : RFC931 20 : deny
37 # Allow anything from localhost. Note that an IP address (not a host
38 # name) *MUST* be specified for rpcbind(8).
39 ALL : localhost 127.0.0.1 : allow
40 ALL : my.machine.example.com 192.0.2.35 : allow
42 # To use IPv6 addresses you must enclose them in []'s
43 ALL : [fe80::%fxp0]/10 : allow
44 ALL : [fe80::]/10 : deny
45 ALL : [3ffe:fffe:2:1:2:3:4:3fe1] : deny
46 ALL : [3ffe:fffe:2:1::]/64 : allow
48 # Sendmail can help protect you against spammers and relay-rapers
49 sendmail : localhost : allow
50 sendmail : .nice.guy.example.com : allow
51 sendmail : .evil.cracker.example.com : deny
52 sendmail : ALL : allow
54 # Exim is an alternative to sendmail, available in the ports tree
55 exim : localhost : allow
56 exim : .nice.guy.example.com : allow
57 exim : .evil.cracker.example.com : deny
60 # Rpcbind is used for all RPC services; protect your NFS!
61 # (IP addresses rather than hostnames *MUST* be used here)
62 rpcbind : 192.0.2.32/255.255.255.224 : allow
63 rpcbind : 192.0.2.96/255.255.255.224 : allow
66 # Provide a small amount of protection for ftpd
67 ftpd : localhost : allow
68 ftpd : .nice.guy.example.com : allow
69 ftpd : .evil.cracker.example.com : deny
72 # You need to be clever with finger; do _not_ backfinger!! You can easily
73 # start a "finger war".
75 : spawn (echo Finger. | \
76 /usr/bin/mail -s "tcpd\: %u@%h[%a] fingered me!" root) & \
79 # The rest of the daemons are protected.
81 : severity auth.info \
82 : twist /bin/echo "You are not welcome to use %d from %h."