> Commands
[root@treebeard ~]#service iptables stop Flushing firewall rules: [ OK ] Setting chains to policy ACCEPT: filter nat [ OK ] Unloading iptables modules: [ OK ] [root@treebeard ~]# service iptables start Applying iptables firewall rules: [ OK ] Loading additional iptables modules: ip_conntrack_netbios_n[ OK ] [root@treebeard ~]# service iptables restart Flushing firewall rules: [ OK ] Setting chains to policy ACCEPT: filter nat [ OK ] Unloading iptables modules: [ OK ] Applying iptables firewall rules: [ OK ] Loading additional iptables modules: ip_conntrack_netbios_n[ OK ] [root@treebeard ~]# iptables-save > /etc/sysconfig/iptables.bak [root@treebeard ~]# cat /etc/sysconfig/iptables.bak # Generated by iptables-save v1.3.5 on Mon Nov 30 12:59:34 2009 *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [15360:12223363] :OUTPUT ACCEPT [293292:381583821] :RH-Firewall-1-INPUT - [0:0] -A INPUT -j RH-Firewall-1-INPUT -A RH-Firewall-1-INPUT -i lo -j ACCEPT -A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT -A RH-Firewall-1-INPUT -p esp -j ACCEPT -A RH-Firewall-1-INPUT -p ah -j ACCEPT -A RH-Firewall-1-INPUT -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT -A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT -A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT -A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT -A RH-Firewall-1-INPUT -p udp -m state --state NEW -m udp --dport 69 -j ACCEPT -A RH-Firewall-1-INPUT -p udp -m state --state NEW -m udp --dport 53 -j ACCEPT -A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT -A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited COMMIT # Completed on Mon Nov 30 12:59:34 2009 # Generated by iptables-save v1.3.5 on Mon Nov 30 12:59:34 2009 *nat :PREROUTING ACCEPT [10747:757361] :POSTROUTING ACCEPT [5694:413946] :OUTPUT ACCEPT [7322:537410] -A POSTROUTING -o eth0 -j MASQUERADE COMMIT # Completed on Mon Nov 30 12:59:34 2009 [root@treebeard ~]#
> Port 80 open for incoming HTTP web requests
[root@treebeard ~]# cat /etc/sysconfig/iptables
# Generated by iptables-save v1.3.5 on Tue Nov 3 09:53:04 2009
*nat
:PREROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [1:70]
-A POSTROUTING -o eth0 -j MASQUERADE
COMMIT
# Completed on Tue Nov 3 09:53:04 2009
# Generated by iptables-save v1.3.5 on Tue Nov 3 09:53:04 2009
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [664:72586]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p esp -j ACCEPT
-A RH-Firewall-1-INPUT -p ah -j ACCEPT
-A RH-Firewall-1-INPUT -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m state --state NEW -m udp --dport 69 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m state --state NEW -m udp --dport 53 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
# Completed on Tue Nov 3 09:53:04 2009
[root@treebeard ~]#
> Showing settings
[root@treebeard ~]# iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination RH-Firewall-1-INPUT all -- anywhere anywhere Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination Chain RH-Firewall-1-INPUT (1 references) target prot opt source destination ACCEPT all -- anywhere anywhere ACCEPT icmp -- anywhere anywhere icmp any ACCEPT esp -- anywhere anywhere ACCEPT ah -- anywhere anywhere ACCEPT udp -- anywhere 224.0.0.251 udp dpt:mdns ACCEPT udp -- anywhere anywhere udp dpt:ipp ACCEPT tcp -- anywhere anywhere tcp dpt:ipp ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:http ACCEPT udp -- anywhere anywhere state NEW udp dpt:tftp ACCEPT udp -- anywhere anywhere state NEW udp dpt:domain ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:ssh REJECT all -- anywhere anywhere reject-with icmp-host-prohibited [root@treebeard ~]# iptables -nL Chain INPUT (policy ACCEPT) target prot opt source destination RH-Firewall-1-INPUT all -- 0.0.0.0/0 0.0.0.0/0 Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination Chain RH-Firewall-1-INPUT (1 references) target prot opt source destination ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 255 ACCEPT esp -- 0.0.0.0/0 0.0.0.0/0 ACCEPT ah -- 0.0.0.0/0 0.0.0.0/0 ACCEPT udp -- 0.0.0.0/0 224.0.0.251 udp dpt:5353 ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:631 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:631 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:80 ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 state NEW udp dpt:69 ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 state NEW udp dpt:53 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited [root@treebeard ~]# iptables -nL --line-numbers Chain INPUT (policy ACCEPT) num target prot opt source destination 1 RH-Firewall-1-INPUT all -- 0.0.0.0/0 0.0.0.0/0 Chain FORWARD (policy ACCEPT) num target prot opt source destination Chain OUTPUT (policy ACCEPT) num target prot opt source destination Chain RH-Firewall-1-INPUT (1 references) num target prot opt source destination 1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 2 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 255 3 ACCEPT esp -- 0.0.0.0/0 0.0.0.0/0 4 ACCEPT ah -- 0.0.0.0/0 0.0.0.0/0 5 ACCEPT udp -- 0.0.0.0/0 224.0.0.251 udp dpt:5353 6 ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:631 7 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:631 8 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED 9 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:80 10 ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 state NEW udp dpt:69 11 ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 state NEW udp dpt:53 12 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22 13 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited [root@treebeard ~]#