Shulou(Shulou.com)06/01 Report--

This article is to share with you about how to analyze the principle of virtual router. The editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

First, let's look at what happened to the linux bridge structure of the control node.

A tape17162c5-00 is added to the bridge of vlan101, and it can be inferred from the name that the TAP device corresponds to the interface of router_100_101 (e17162c5-00fa).

A tapd568ba1a-74 is added to the bridge of vlan100, and it can be inferred from the name that the TAP device corresponds to the interface (d568ba1a-740e) of router_100_101.

However, a problem was found: the corresponding Gateway IP was not configured on both TAP devices.

How can routing be done without Gateway IP,router_100_101?

The answer is: L3 agent creates a namespace for each router, connects to the TAP through the veth pair, and then configures the Gateway IP on the veth interface located in the namespace so that routing can be provided.

View namespace through ip netns:

The namespace corresponding to router is named qrouter-.

View the veth interface configuration in router_100_101 namespace through the ip netns exec ip a command.

There are two interface in namespace:

Gateway IP 172.16.101.1 is set on qr-e17162c5-00 to form a veth pair with tape17162c5-00 in root namespace.

Gateway IP 172.16.100.1 is set on qr-d568ba1a-74 to form veth pair with tapd568ba1a-74 in root namespace.

The routing table in namespace also ensures that the subnet_172_16_100_0 and subnet_172_16_101_0 can be routed.

At this point in the analysis, we have figured out how router_100_101 got through to vlan100 and vlan 101.

The above is how to carry on the virtual router principle analysis, the editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.