BrainwreckedTech: /* Configure IPTables */ Commented iptables.rules file

2019-12-07T23:48:49Z

Configure IPTables: Commented iptables.rules file

← Older revision		Revision as of 19:48, 7 December 2019
Line 13:		Line 13:
	# SIMPLE STATEFUL FIREWALL		# SIMPLE STATEFUL FIREWALL
	*filter		*filter

			# CONFIGURE DEFAULT CHAINS
	:INPUT DROP [0:0]		:INPUT DROP [0:0]
	:FORWARD DROP [0:0]		:FORWARD DROP [0:0]
	:OUTPUT ACCEPT [100308:88697975]		:OUTPUT ACCEPT [100308:88697975]

			# ADD USER CHAINS
	:TCP - [0:0]		:TCP - [0:0]
	:UDP - [0:0]		:UDP - [0:0]

			# ALLOW ESTABLISHED CONNECTIONS, AND CONNECTIONS RELATED TO SUCH
	-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT		-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

			# ALLOW CONNECTIONS FROM LOCALHOST
	-A INPUT -i lo -j ACCEPT		-A INPUT -i lo -j ACCEPT

			# DROP PACKETS THAT HAVE INVALID HEADERS, CHECKSUMS, TCP FLAGS, OR ICMP MESSAGE; AND PACKETS OUT OF SEQUENCE
			-A INPUT -m conntrack --ctstate INVALID -j DROP

			# ALLOW PINGS
	-A INPUT -p icmp -m icmp --icmp-type 8 -m conntrack --ctstate NEW -j ACCEPT		-A INPUT -p icmp -m icmp --icmp-type 8 -m conntrack --ctstate NEW -j ACCEPT
	~~-A INPUT -m conntrack --ctstate INVALID -j DROP~~
			# RESET CONNECTIONS THAT ARE NEW WITH NO CORRESPONDING SYN
	-A INPUT -p udp -m conntrack --ctstate NEW -j UDP		-A INPUT -p udp -m conntrack --ctstate NEW -j UDP
	-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j TCP		-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j TCP

			# REJECT UDP STREAMS IF PORT IS NOT OPEN
	-A INPUT -p udp -j REJECT --reject-with icmp-port-unreachable		-A INPUT -p udp -j REJECT --reject-with icmp-port-unreachable

			# REJECT TCP CONNECTION IF PORT IS NOT OPEN
	-A INPUT -p tcp -j REJECT --reject-with tcp-reset		-A INPUT -p tcp -j REJECT --reject-with tcp-reset

			# REJECT ALL OTHER TRAFFIC
	-A INPUT -j REJECT --reject-with icmp-proto-unreachable		-A INPUT -j REJECT --reject-with icmp-proto-unreachable

	# OPEN NECESSARY PORTS HERE		# OPEN NECESSARY PORTS HERE
	-A TCP -p tcp -m tcp --dport 22 -j ACCEPT -m comment --comment "ssh"		-A TCP -p tcp -m tcp --dport 22 -j ACCEPT -m comment --comment "ssh"
			-A TCP -p tcp -m tcp --dport 25 -j ACCEPT -m comment --comment "smtp"
	-A TCP -p tcp -m tcp --dport 80 -j ACCEPT -m comment --comment "http"		-A TCP -p tcp -m tcp --dport 80 -j ACCEPT -m comment --comment "http"
	-A TCP -p tcp -m tcp --dport 443 -j ACCEPT -m comment --comment "https"		-A TCP -p tcp -m tcp --dport 443 -j ACCEPT -m comment --comment "https"
Line 36:		Line 57:
	-A TCP -p tcp -m tcp --dport 873 -j ACCEPT -m comment --comment "rsync"		-A TCP -p tcp -m tcp --dport 873 -j ACCEPT -m comment --comment "rsync"
	-A TCP -p tcp -m tcp --dport 993 -j ACCEPT -m comment --comment "imaps"		-A TCP -p tcp -m tcp --dport 993 -j ACCEPT -m comment --comment "imaps"
	-A TCP -p tcp -m tcp --dport ~~64738~~ -j ACCEPT -m comment --comment "~~mumble tcp~~"		-A TCP -p tcp -m tcp --dport 995 -j ACCEPT -m comment --comment "pop3s"
	~~-A UDP -p udp -m udp --dport 64738 -j ACCEPT -m comment --comment "mumble udp"~~
	COMMIT		COMMIT
	}}		}}

BrainwreckedTech: Created Simple Stateful Firewall

2019-12-07T22:26:04Z

Created Simple Stateful Firewall

New page

[[Category:Firewall]]
= Prerequisites =

Most, if not all, GNU/Linux distributions ship a default kernel that has the netfilter module.

= Required Packages =

Most, if not all, GNU/Linux distributions have the {{ic|iptables}} package/binary installed by default.

= Configure IPTables =

{{hc|/etc/iptables/iptables.rules|2=
# SIMPLE STATEFUL FIREWALL
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [100308:88697975]
:TCP - [0:0]
:UDP - [0:0]
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 8 -m conntrack --ctstate NEW -j ACCEPT
-A INPUT -m conntrack --ctstate INVALID -j DROP
-A INPUT -p udp -m conntrack --ctstate NEW -j UDP
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j TCP
-A INPUT -p udp -j REJECT --reject-with icmp-port-unreachable
-A INPUT -p tcp -j REJECT --reject-with tcp-reset
-A INPUT -j REJECT --reject-with icmp-proto-unreachable

# OPEN NECESSARY PORTS HERE
-A TCP -p tcp -m tcp --dport 22 -j ACCEPT -m comment --comment "ssh"
-A TCP -p tcp -m tcp --dport 80 -j ACCEPT -m comment --comment "http"
-A TCP -p tcp -m tcp --dport 443 -j ACCEPT -m comment --comment "https"
-A TCP -p tcp -m tcp --dport 465 -j ACCEPT -m comment --comment "smtps"
-A TCP -p tcp -m tcp --dport 587 -j ACCEPT -m comment --comment "starttls"
-A TCP -p tcp -m tcp --dport 873 -j ACCEPT -m comment --comment "rsync"
-A TCP -p tcp -m tcp --dport 993 -j ACCEPT -m comment --comment "imaps"
-A TCP -p tcp -m tcp --dport 64738 -j ACCEPT -m comment --comment "mumble tcp"
-A UDP -p udp -m udp --dport 64738 -j ACCEPT -m comment --comment "mumble udp"
COMMIT
}}

Simple Stateful Firewall - Revision history

BrainwreckedTech: /* Configure IPTables */ Commented iptables.rules file

BrainwreckedTech: Created Simple Stateful Firewall