Linux Networking

Routing

Tutorials

rule/table routing intro

https://blog.scottlowe.org/2013/05/29/a-quick-introduction-to-linux-policy-routing/

Routing

     packet
       |
       |
  routing-policy
       |
       |
      \ /
       `
  routing-table

Routing Policy

The routing policy is managed by iproute2.

Routing Table

routing tables determine what network a packets is sent to.
A variety of tools can be used to manage it, but iproute2 is generally used today.

Prior to iproute2, net-tools route was generally used to manage the routing table in Linux.
You can also dump the routing table with netstat -r.

Firewall

Both iptables and more recently nftables are builtin to the linux kernel to manage rules.
There are also various abstractions overtop of them.