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 based on functions, departments and applications and other factors to organize them, communication with each other as if they are in the same network segment, hence the name of the virtual local area network. VLAN is a relatively new technology that works on layers 2nd and 3rd of the OSI Reference Model, where a VLAN is a broadcast domain, and communication between 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 mobile, add and modify of network equipment management cost is reduced, can control the broadcast activity, can improve the security of the network.
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.
Trunk is interpreted as "port aggregation", which is an important way of bandwidth expansion and link backup. TRUNK (port aggregation) is the ability to bring together multiple physical ports of a switch to form a logical physical port, and multiple links within the same aggregation group can be considered as a single logical link. Port aggregation enables the aggregation of multiple links into a single logical link to increase the bandwidth, while the individual member ports of the same aggregation group are dynamically backed up to improve connectivity reliability.
1: Next-facing VLAN partitioning, port aggregation
2: Enter SW1 SW1
Add VLAN 20 VLAN
3: Configure ports for SW1 SW2, respectively
4: Set TURNK aggregation below
Select port
Select Encapsulation Protocol dot1q
Port set to Trunk
5: To the PC-side test of interoperability
It can be seen that only the same VLAN can interoperate.
Configuration complete
VLAN partitioning and trunk aggregation in Linux Redhat6.5
