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# |
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# /etc/bastille-firewall.cfg |
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# |
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# Configuration fiel for both 2.2/ipchains and 2.4/netfilter scripts |
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# |
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# version 0.99-beta1 |
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# Copyright (C) 1999-2001 Peter Watkins |
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# |
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# This program is distributed in the hope that it will be useful, |
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# but WITHOUT ANY WARRANTY; without even the implied warranty of |
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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# GNU General Public License for more details. |
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# |
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# You should have received a copy of the GNU General Public License |
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# along with this program; if not, write to the Free Software |
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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# |
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# Thanks to David Ranch, Brad A, Don G, and others for their suggestions |
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|
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# the configuration values should be whitespace-delimited lists of |
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# appropriate values, e.g. |
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# TCP_PUBLIC_SERVICES="80 smtp ssh" |
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# lists Web (port 80), SMTP mail, and Secure Shell ports |
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# |
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# This script is suitable for workstations or simple NAT firewalls; |
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# you may want to add more "output" restrictions for serious servers |
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|
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# 0) DNS servers. You must list your DNS servers here so that |
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# the firewall will allow them to service your lookup requests |
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# |
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# List of DNS servers/networks to allow "domain" responses from |
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# This _could_ be nameservers as a list of <ip-address>/32 entries |
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#DNS_SERVERS="a.b.c.d/32 e.f.g.h/32" |
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# If you are running a caching nameserver, you'll need to allow from |
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# "0.0.0.0/0" so named can query any arbitrary nameserver |
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# (To enable a caching nameserver, you will also probably need to |
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# add "domain" to the TCP and UDP public service lists.) |
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#DNS_SERVERS="0.0.0.0/0" |
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# |
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# To have the DNS servers parsed from /etc/resolv.conf at runtime, |
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# as normal workstations will want, make this variable empty |
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#DNS_SERVERS="" |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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DNS_SERVERS="" |
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|
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|
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# 1) define your interfaces |
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# Note a "+" acts as a wildcard, e.g. ppp+ would match any PPP |
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# interface |
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# |
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# list internal/trusted interfaces |
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# traffic from these interfaces will be allowed |
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# through the firewall, no restrictions |
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#TRUSTED_IFACES="lo" # MINIMAL/SAFEST |
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# |
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# list external/untrusted interfaces |
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#PUBLIC_IFACES="eth+ ppp+ slip+" # SAFEST |
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# |
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# list internal/partially-trusted interfaces |
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# e.g. if this acts as a NAT/IP Masq server and you |
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# don't want clients on those interfaces having |
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# full network access to services running on this |
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# server (as the TRUSTED_IFACES allows) |
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#INTERNAL_IFACES="" # SAFEST |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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TRUSTED_IFACES="lo" # MINIMAL/SAFEST |
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PUBLIC_IFACES="eth+ ppp+" # SAFEST |
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INTERNAL_IFACES="" # SAFEST |
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|
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|
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# 2) services for which we want to log access attempts to syslog |
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# Note this only audits connection attempts from public interfaces |
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# |
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# Also see item 12, LOG_FAILURES |
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# |
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#TCP_AUDIT_SERVICES="telnet ftp imap pop3 finger sunrpc exec login linuxconf ssh" |
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# anyone probing for BackOrifice? |
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#UDP_AUDIT_SERVICES="31337" |
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# how about ICMP? |
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#ICMP_AUDIT_TYPES="" |
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#ICMP_AUDIT_TYPES="echo-request" # ping/MS tracert |
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# |
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# To enable auditing, you must have syslog configured to log "kern" |
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# messages of "info" level; typically you'd do this with a line in |
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# syslog.conf like |
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# kern.info /var/log/messages |
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# though the Bastille port monitor will normally want these messages |
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# logged to a named pipe instead, and the Bastille script normally |
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# configures syslog for "kern.*" which catches these messages |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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TCP_AUDIT_SERVICES="" |
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UDP_AUDIT_SERVICES="" |
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ICMP_AUDIT_TYPES="" |
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|
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|
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# 3) services we allow connections to |
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# |
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# FTP note: |
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# To allow your machine to service "passive" FTP clients, |
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# you will need to make allowances for the passive data |
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# ports; Bastille users should read README.FTP for more |
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# information |
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# |
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# "public" interfaces: |
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# TCP services that "public" hosts should be allowed to connect to |
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#TCP_PUBLIC_SERVICES="" # MINIMAL/SAFEST |
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# |
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# UDP services that "public" hosts should be allowed to connect to |
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#UDP_PUBLIC_SERVICES="" # MINIMAL/SAFEST |
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# |
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# "internal" interfaces: |
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# (NB: you will need to repeat the "public" services if you want |
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# to allow "internal" hosts to reach those services, too.) |
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# TCP services that internal clients can connect to |
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#TCP_INTERNAL_SERVICES="" # MINIMAL/SAFEST |
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# |
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# UDP services that internal clients can connect to |
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#UDP_INTERNAL_SERVICES="" # MINIMAL/SAFEST |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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#TCP_PUBLIC_SERVICES="109 53 143 80 20 21 22 110 443 25" # MINIMAL/SAFEST |
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TCP_PUBLIC_SERVICES="" # MINIMAL/SAFEST |
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UDP_PUBLIC_SERVICES="" # MINIMAL/SAFEST |
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TCP_INTERNAL_SERVICES="www ssh" # MINIMAL/SAFEST |
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UDP_INTERNAL_SERVICES="" # MINIMAL/SAFEST |
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|
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# 4) FTP is a firewall nightmare; if you allow "normal" FTP connections, |
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# you must be careful to block any TCP services that are listening |
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# on high ports; it's safer to require your FTP clients to use |
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# "passive" mode. |
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# |
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# Note this will also force clients on machines |
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# that use this one for NAT/IP Masquerading to use passive mode |
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# for connections that go through this server (e.g. from the |
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# internal network to public Internet machines |
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# |
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# For more information about FTP, see the Bastille README.FTP doc |
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# |
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#FORCE_PASV_FTP="N" |
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#FORCE_PASV_FTP="Y" # SAFEST |
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# |
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FORCE_PASV_FTP="N" # SAFEST |
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|
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|
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# 5) Services to explicitly block. See FTP note above |
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# Note that ranges of ports are specified with colons, and you |
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# can specify an open range by using only one number, e.g. |
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# 1024: means ports >= 1024 and :6000 means ports <= 6000 |
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# |
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# TCP services on high ports that should be blocked if not forcing passive FTP |
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# This should include X (6000:6010) and anything else revealed by 'netstat -an' |
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# (this does not matter unless you're not forcing "passive" FTP) |
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#TCP_BLOCKED_SERVICES="6000:6020" |
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# |
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# UDP services to block: this should be UDP services on high ports. |
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# Your only vulnerability from public interfaces are the DNS and |
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# NTP servers/networks (those with 0.0.0.0 for DNS servers should |
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# obviously be very careful here!) |
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#UDP_BLOCKED_SERVICES="2049" |
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# |
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# types of ICMP packets to allow |
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#ICMP_ALLOWED_TYPES="destination-unreachable" # MINIMAL/SAFEST |
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# the following allows you to ping/traceroute outbound |
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#ICMP_ALLOWED_TYPES="destination-unreachable echo-reply time-exceeded" |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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TCP_BLOCKED_SERVICES="6000:6020" |
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UDP_BLOCKED_SERVICES="2049" |
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ICMP_ALLOWED_TYPES="destination-unreachable echo-reply time-exceeded" |
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|
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|
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# 6) Source Address Verification helps prevent "IP Spoofing" attacks |
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# |
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ENABLE_SRC_ADDR_VERIFY="Y" # SAFEST |
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|
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|
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# 7) IP Masquerading / NAT. List your internal/masq'ed networks here |
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# |
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# Also see item 4, FORCE_PASV_FTP, as that setting affects |
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# clients using IP Masquerading through this machine |
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# |
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# Set this variable if you're using IP Masq / NAT for a local network |
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#IP_MASQ_NETWORK="" # DISABLE/SAFEST |
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#IP_MASQ_NETWORK="10.0.0.0/8" # example |
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#IP_MASQ_NETWORK="192.168.0.0/16" # example |
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# |
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# Have lots of masq hosts? uncomment the following six lines |
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# and list the hosts/networks in /etc/firewall-masqhosts |
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# the script assumes any address without a "/" netmask afterwards |
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# is an individual address (netmask /255.255.255.255): |
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#if [ -f /etc/firewall-masqhosts ]; then |
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# echo "Reading list of masq hosts from /etc/firewall-masqhosts" |
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# # Read the file, but use 'awk' to strip comments |
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# # Note the sed bracket phrase includes a space and tab char |
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# IP_MASQ_NETWORK=`cat /etc/firewall-masqhosts | awk -F\# '/\// {print $1; next} /[0-9]/ {print $1"/32"}' |sed 's:[ ]*::g'` |
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#fi |
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# |
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# Masq modules |
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# NB: The script will prepend "ip_masq_" to each module name |
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#IP_MASQ_MODULES="cuseeme ftp irc quake raudio vdolive" # ALL (?) |
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#IP_MASQ_MODULES="ftp raudio vdolive" # RECOMMENDED |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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IP_MASQ_NETWORK="192.168.4.0/24" # DISABLE/SAFEST |
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IP_MASQ_MODULES="" # RECOMMENDED |
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|
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|
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# 8) How to react to disallowed packets |
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# whether to "REJECT" or "DENY" disallowed packets; if you're running any |
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# public services, you probably ought to use "REJECT"; if in serious stealth |
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# mode, choose "DENY" so simple probes don't know if there's anything out there |
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# NOTE: disallowed ICMP packets are discarded with "DENY", as |
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# it would not make sense to "reject" the packet if you're |
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# trying to disallow ping/traceroute |
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# |
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REJECT_METHOD="DENY" |
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|
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|
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# 9) DHCP |
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# In case your server needs to get a DHCP address from some other |
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# machine (e.g. cable modem) |
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#DHCP_IFACES="eth0" # example, to allow you to query on eth0 |
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#DHCP_IFACES="" # DISABLED |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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DHCP_IFACES="" # DISABLED |
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|
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|
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# 10) more UDP fun. List IP addresses or network space of NTP servers |
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# |
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#NTP_SERVERS="" # DISABLE NTP QUERIES / SAFEST |
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#NTP_SERVERS="a.b.c.d/32 e.f.g.h/32" # example, to allow querying 2 servers |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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NTP_SERVERS="" # DISABLE NTP QUERIES / SAFEST |
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|
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|
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# 11) more ICMP. Control the outbound ICMP to make yourself invisible to |
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# traceroute probes |
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# |
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#ICMP_OUTBOUND_DISABLED_TYPES="destination-unreachable time-exceeded" |
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# |
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# Please make sure variable assignments are on single lines; do NOT |
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# use the "\" continuation character (so Bastille can change the |
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# values if it is run more than once) |
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ICMP_OUTBOUND_DISABLED_TYPES="destination-unreachable time-exceeded" |
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|
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|
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# 12) Logging |
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# With this enabled, ipchains will log all blocked packets. |
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# ** this could generate huge logs ** |
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# This is primarily intended for the port mointoring system; |
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# also note that you probably do not want to "AUDIT" any services |
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# that you are not allowing, as doing so would mean duplicate |
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# logging |
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LOG_FAILURES="N" # do not log blocked packets |
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|
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# 13) Block fragmented packets |
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# There's no good reason to allow these |
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#ALLOW_FRAGMENTS="N" # safest |
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ALLOW_FRAGMENTS="Y" # old behavior |
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|
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# 14) Prevent SMB broadcasts from leaking out NAT setup |
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# Windows machines will poll teh net with SMB broadcasts, |
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# basically advertising their existence. Most folks agree |
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# that this traffic should be dropped |
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#DROP_SMB_NAT_BCAST="N" # allow them (are you sure?) |
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DROP_SMB_NAT_BCAST="Y" # drop those packets |
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