Moxa UC-8481-T-LX [35/90] Iptables a input i eth0 p tcp dport 25 j log

UC-8410/8416/8418/8430 Managing Communication

4-8

--dport: Destination port number.

-j: Jump target. Specifies the target of the rules; i.e., how to handle matched packets.

For example, ACCEPT the packet, DROP the packet, or LOG the packet.

Examples:

Example 1: Accept all packets from lo interface.

# iptables –A INPUT –i lo –j ACCEPT

Example 2: Accept TCP packets from 192.168.0.1.

# iptables –A INPUT –i eth0 –p tcp –s 192.168.0.1 –j ACCEPT

Example 3: Accept TCP packets from Class C network 192.168.1.0/24.

# iptables –A INPUT –i eth0 –p tcp –s 192.168.1.0/24 –j ACCEPT

Example 4: Drop TCP packets from 192.168.1.25.

# iptables –A INPUT –i eth0 –p tcp –s 192.168.1.25 –j DROP

Example 5: Drop TCP packets addressed for port 21.

# modprobe xt_tcpudp

# iptables –A INPUT –i eth0 –p tcp --dport 21 –j DROP

Example 6: Accept TCP packets from 192.168.0.24 to LAN1 port 137, 138, 139

# iptables –A INPUT –i eth0 –p tcp –s 192.168.0.24 --dport 137:139 –j ACCEPT

Example 7: Log TCP packets that visit the LAN1 port 25.

# iptables –A INPUT –i eth0 –p tcp --dport 25 –j LOG

Example 8: Drop all packets from MAC address 01:02:03:04:05:06.

# modprobe xt_mac

# iptables –A INPUT –i eth0 –p all –m mac -–mac-source 01:02:03:04:05:06 –j DROP

NOTE: In Example 8, remember to issue the command #modprobe ipt_mac first to load the module xt_mac

NAT

NAT (Network Address Translation) protocol translates IP addresses used on one network to different IP

addresses used on another network. One network is designated the inside network and the other is the outside

network. Typically, the UC-8410/8416/8418/8430/8430 connects several devices on a network and maps local

inside network addresses to one or more global outside IP addresses, and un-maps the global IP addresses on

incoming packets back into local IP addresses.

NOTE Click the following link for more information about iptables and NAT:

http://www.netfilter.org/documentation/HOWTO/NAT-HOWTO.html