linux - How can I port forward with iptables? - Server Fault
$ iptables -t nat -A PREROUTING -d @pub -i eth0 -j DNAT --to-destination @priv. Let's modify the table nat, append a rule to the pretrouting section : something is trying to reach @pub ? Let's put it in our input interface eth0, jump to the Destination Nat protocol, which tells us to send the packet to @priv. Now Let's modify the POSTROUTING # /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE # /sbin/iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT # /sbin/iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT You should now be NATing. You can test this by pinging an external address from one of your internal hosts. iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE The “liberal” form is better for temporary connections: MASQUERADE automatically chooses address Jun 16, 2020 · The iptables is the most useful and powerful tool for the Linux operating system; it has all capabilities what having a typical firewall. It is a handy utility for every Linux administrator or engineers, and mostly we have to work with it daily. If you want to know more about iptables you can go through the iptables manual page: Feb 01, 2010 · This is only valid if the rule also specifies -p tcp or -p udp. The OUTPUT chain example: iptables -t nat -I OUTPUT --src 0/0 --dst 192.168.1.5 -p tcp --dport 80 -j REDIRECT --to-ports 8123. iptables -t nat -I OUTPUT --src 0/0 --dst 192.168.1.5 -p tcp --dport 80 -j REDIRECT --to-ports 8123.
iptables command in Linux with Examples iptables is a command line interface used to set up and maintain tables for the Netfilter firewall for IPv4, included in the Linux kernel. The firewall matches packets with rules defined in these tables and then takes the specified action on a possible match.
linux - Iptables NAT one-to-one - Stack Overflow iptables -nvL -t nat Chain PREROUTING (policy ACCEPT 36 packets, 2476 bytes) pkts bytes target prot opt in out source destination 8 528 DNAT all -- eth0 * 0.0.0.0/0 172.10.1.101 to:192.168.1.10 Chain INPUT (policy ACCEPT 36 packets, 2476 bytes) pkts bytes target prot opt in out source destination Chain OUTPUT (policy ACCEPT 195 packets, 14344 iptables Syntax | iptables: The Linux Firewall This chapter covers the iptables firewall administration program used to build a Netfilter firewall. For those of you who are familiar with or accustomed to the older ipfwadm and ipchains programs used with the IPFW technology, iptables will look very similar to those programs. However, it is much more feature-rich and flexible, and it is very different on subtle levels.
#!/bin/bash # first cleanup everything iptables -t filter -F iptables -t filter -X iptables -t nat -F iptables -t nat -X # default drop iptables -P INPUT DROP iptables -P FORWARD DROP iptables -P OUTPUT DROP # allow loopback device iptables -A INPUT -i lo -j ACCEPT iptables -A OUTPUT -o lo -j ACCEPT # allow ssh over eth0 from outside to system
How to Set Up Gateway Using iptables and route on Linux Feb 20, 2020 linux - Iptables NAT one-to-one - Stack Overflow iptables -nvL -t nat Chain PREROUTING (policy ACCEPT 36 packets, 2476 bytes) pkts bytes target prot opt in out source destination 8 528 DNAT all -- eth0 * 0.0.0.0/0 172.10.1.101 to:192.168.1.10 Chain INPUT (policy ACCEPT 36 packets, 2476 bytes) pkts bytes target prot opt in out source destination Chain OUTPUT (policy ACCEPT 195 packets, 14344 iptables Syntax | iptables: The Linux Firewall This chapter covers the iptables firewall administration program used to build a Netfilter firewall. For those of you who are familiar with or accustomed to the older ipfwadm and ipchains programs used with the IPFW technology, iptables will look very similar to those programs. However, it is much more feature-rich and flexible, and it is very different on subtle levels.