# 計算機網路 - flowtable

[TOC]

> *The motivation of it [flow table] was actually the realization that ==packets that go through connections that are in ESTABLISHED state always do the same thing==, so what can be done is that if we put a flow table in the beginning, before we start the ingress processing, to check if the packets that were just received is part of an ESTABLISHED connection, ==then basically we can just do the packet manipulation that is required, such as NAT address rewrite, and TTL decrement, and then just forward the packet to the egress device==. If we have this set up, we could basically bypass all the chains … bypass everything and go from ingress processing directly to the egress processing.*
> --- [*TC Connection tracking hardware offload, netdev 0x14*](https://youtu.be/gWklbJSk0YI)

## 參考影片

### LPC2019 - Netfilter Hardware Offloads

{%youtube Fh5qWz-ePXU %}

### Netdev 0x14 - TC Connection tracking hardware offload

{%youtube gWklbJSk0YI %}

### Conntrack offload: why and how - DevConf.CZ 2021

{%youtube sst35r4cRsI %}