Linux iptables has SNAT, DNAT & MASQUERADE rules. Masquerade was introduced in earlier versions of Linux "firewalling". As you can see below and in the post above the definition of SNAT & DNAT

Iptables and ip6tables are used to set up, maintain, and inspect the tables of IPv4 and IPv6 packet filter rules in the Linux kernel. Several different tables may be defined. Several different tables may be defined. sudo iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE I am seeing in wireshark at eth0, that during ping request source ip changes from DUT ip to host ip (i.e eth0 ip) but that does not happen while ping reply , destination IP remains host IP only. Docker and iptables Estimated reading time: 4 minutes On Linux, Docker manipulates iptables rules to provide network isolation. While this is an implementation detail and you should not modify the rules Docker inserts into your iptables policies, it does have some implications on what you need to do if you want to have your own policies in addition to those managed by Docker. 3.4.1. Configuring IP Masquerade on Linux 2.6.x and 2.4.x Kernels. Please note that IPCHAINS is no longer the primary firewall configuration tool for the 2.6.x and 2.4.x kernels.

Dec 05, 2008 · By using iptables and its masquerade feature, it is possible to forward all traffic to the old server to the new IP. This tutorial will show which command lines are required to make this possible. In this article, it is assumed that you do not have iptables running, or at least no nat table rules for chain PREROUTING and POSTROUTING .

iptables is a pure packet filter when using the default 'filter' table, with optional extension modules. This should simplify much of the previous confusion over the combination of IP masquerading and packet filtering seen previously. MASQUERADE and IPTABLES make to work. Ask Question Asked 7 years, 11 months ago. Active 7 years, 9 months ago. Viewed 577 times 0. Got problem with IPTABLES, have two Feb 02, 2016 · I’d like to share some gotchas after reading iptables tutorial for the 2nd time ;-D. Gotchas SNAT Target VS MASQUERADE Target. Both targets do source NAT (or SNAT) in the POSTROUTING chain in the nat table. Differences. MASQUERADE does NOT require --to-source as it was made to work with dynamically assigned IP addresses. SNAT works with

nftables replaces the legacy iptables portions of Netfilter. Among the advantages of nftables over iptables is less code duplication and easier extension to new protocols. nftables is configured via the user-space utility nft, while legacy tools are configured via the utilities iptables, ip6tables, arptables and ebtables frameworks.

Jul 17, 2018 · Fig.01: Linux viewing all iptables NAT, DNAT, MASQUERADE rules. Say hello to ip6tables. ip6tables is administration tool for IPv6 packet filtering and NAT. To see IPv6 tables, enter: # ip6tables -L -n -v