User`s manual

UC-7408 User’s Manual Managing Communication

4-10

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 ixp0 –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 ixp0 –p tcp –s 192.168.1.0/24 –j ACCEPT

Example 4: Drop TCP packets from 192.168.1.25.

# iptables –A INPUT –i ixp0 –p tcp –s 192.168.1.25 –j DROP

Example 5: Drop TCP packets addressed for port 21.

# iptables –A INPUT –i ixp0 –p tcp --dport 21 –j DROP

Example 6: Accept TCP packets from 192.168.0.24 to UC-7408’s port 137, 138, 139

# iptables –A INPUT –i ixp0 –p tcp –s 192.168.0.24 --dport 137:139 –j ACCEPT

Example 7: Log TCP packets that visit UC-7408’s port 25.

# iptables –A INPUT –i ixp0 –p tcp --dport 25 –j LOG

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

# iptables –A INPUT –i ixp0 –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 module

ipt_mac.

NAT

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

different IP addresses used on another network. One network is designated the inside network and

the other is the outside network. Typically, UC-7408 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 on the following link for more information about iptables and NAT:

http://www.netfilter.org/documentatio

HOWTO/NAT-HOWTO.html