Contents
What are the tables used in iptables?
IPTables has the following 4 built-in tables.
- Filter Table. Filter is default table for iptables.
- NAT table. Iptable’s NAT table has the following built-in chains.
- Mangle table. Iptables’s Mangle table is for specialized packet alteration.
- Raw table. Iptable’s Raw table is for configuration excemptions.
Should I use Nftables or IPtables?
Nftables is easier to use and combines all tools of the IPtables framework (e. g. iptables, ip6tables, arptables, etc.) in a single tool. The syntax has also become better and easier, but there is a compatibility layer so you could still use the old IPtables syntax even if filtering is internally done with nftables.
How does the Netfilter framework work with iptables?
Each module will be called in turn and will return a decision to the netfilter framework after processing that indicates what should be done with the packet. The iptables firewall uses tables to organize its rules. These tables classify rules according to the type of decisions they are used to make.
How are rules organized in the iptables firewall?
The iptables firewall uses tables to organize its rules. These tables classify rules according to the type of decisions they are used to make. For instance, if a rule deals with network address translation, it will be put into the nat table.
While tables are defined by the general aim of the rules they hold, the built-in chains represent the netfilter hooks which trigger them. Chains basically determine when rules will be evaluated. As you can see, the names of the built-in chains mirror the names of the netfilter hooks they are associated with:
How are non-terminating targets used in Netfilter?
Non-terminating targets: Non-terminating targets perform an action and continue evaluation within the chain. Although each chain must eventually pass back a final terminating decision, any number of non-terminating targets can be executed beforehand. The availability of each target within rules will depend on context.