Get the latest tech news
Linux Routing Fundamentals
has been a first class networking citizen for quite a long time now. Every box running a Linux kernel out of the box has at least three routing tables and is supporting multiple mechanisms for advanced routing features from policy based routing (PBR), to VRFs(-lite), and network namespaces (NetNS).
The next-hop is the IP address of a device, directly reachable from the local machine, either via a shared network segment or tunnel, which is the next router on a path to a given destination. Another interesting thing that’s happening while the routing decision for locally generated traffic is made is that the source address for the packets is selected (if not explicitly specified by the application). Contrary to intuition, the policy based routing framework, which can be used for fairly advanced magic and trickery, is always in use, even when not doing anything fancy on your Linux system.
Or read this on Hacker News