Virtualization VI, Network virtualization Technology 2

Source: Internet
Author: User

First, the switch


The Chinese name of the VLAN (virtual local area network) is "virtualized LAN".

Virtual local Area network (VLAN) is a set of logical devices and users, these devices and users are not limited by the physical location, can be organized according to functions, departments and applications and other factors, communication between them as if they are in the same network segment , resulting in

Virtual local Area network.

VLAN is a relatively new technology that works in in the 2nd and 3rd layers of the OSI Reference Model, a VLAN is a broadcast domain , and the communication between the VLANs is done through the router on the 3rd layer . Compared with the traditional LAN technology , VLAN technology is more flexible, it has the following advantages:

The management overhead of moving, adding and modifying network devices is reduced , the broadcast activity can be controlled, and the security of the network can be improved .

In a computer network, a two-layer network can be divided into different broadcast domains, a broadcast domain corresponding to a specific user group, by default, these different broadcast domains are isolated from each other. To communicate between different broadcast domains, you need to pass one or more routers. Such a broadcast domain is called a VLAN.

What is a VLAN?

Virtual LAN; LAN is the range of nodes that the broadcast frame can reach, that is, the scope of direct communication;

How VLANs are divided:

Based on MAC address

Switch Port-based implementation

Based on IP address implementation

Based on user implementation

Type of Switch interface:

Access Links: Access link

Aggregation Link: trunc link

How VLANs are aggregated:

IEEE 802.1q

Isl:inter Switch Link

VXLAN (extended VLAN): Capable of dividing more VLANs

Enable Linu to support VLANs:

[Email protected]_173 ~]# [[email protected]_173 ~]# modinfo 8021qfilename:/lib/modules/2.6.32-573.el6.x86_64/kern El/net/8021q/8021q.koversion:1.8license:gplalias:rtnl-link-vlansrcversion:24ca9e14200e9b54d 970303depends:garpvermagic:2.6.32-573.el6.x86_64 SMP mod_unload modversions [[Email protected]_173 ~]# MODP Robe 8021q[[email protected]_173 ~]# ls/proc/net/vlanconfig

Inter-VLAN Routing:


Access Link: Router provides an interface for each VLAN

Aggregation Link: Router only provides an interface to the interchange #单臂路由

Three-layer switch:

Virtualization VI, Network virtualization Technology 2

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