VLAN (Virtual Area Network) is a separate network connection in the form of a domain called Domain. The purpose of this separation into Domain is so that computers in different domains cannot communicate with each other. Network As well as can increase the performance of the network as well A network can consist of several switching hubs, and in a switching hub it can containmultiple VLANs or multiple VLANs.Connected in the same Switches Hub, but in different VLANs, cannot communicate with each other. They are not even visible (Fig. 1). Of course, one VLAN can be distributed among different Switches Hubs as well. Under a Cisco Switch Hub, up to 64 VLANs can be installed and The entire system can have up to 1024 VLANs.
Common VLAN features are
Each VLAN that is connected to it Will look like connected with a separate bridge
VLAN can connect multiple switches.
Trunks and trunk 41 will receive the rafig of each VLAN.
Benefits of VLAN
- Limit the spread of broadcast traffic from affecting the overall performance of Network or call 1 VLAN is 1 Broadcast Domain itself
- Could create a safety mechanism more easily, such as creating Access Control List on Layer3 and reduce the risks associated with capturing data (Sniffing)
- Faint to be able to move. Move to other VLANs (Subnets) by simply changing switch config and Client IP address. No switch or cable relocation required
- easy future expansion of the network Due to the planning of sebnet and system design that is no longer physically attached.
- Able to analyze problems that occur in the system more easily, such as in the system, there are divided VLANs into 3 departments, including sale, engineer and server.One day, the user of the sale calls to report the problem to the admin that can not play the Internet, we are the Admin should ask. user returns to whether others in the department are as well or not. If not, then it is the only person's machine. But if it is a whole department I have to call to check with the engineer department whether it is the same or not. If not, it means that it is at the sale department only, so check the problem at the sales department only.Much easier and the scope for problem analysis is narrower More importantly, when solving problems, it should bring the principle of OSILayer to help. Will make it easier to find the cause
To create a VLAN, the switch port has two types of functions: Access port and Trunk port, which have different functions according to the System Administrator. Will be the one set In which the main functions of both are
Access Port
This is Port that serves to connect switch from Client to switch, which we will use a straight-through Lan cable to connect and the port that is set to Access Port will have only one VLAN traffic that VLAN. This port is connected to a device with only one mac address, for example – port set between switch and Client – port set between switch and Server – port set between switch and Router (have Although the router connected must not be a router that serves to route Inter VLAN traffic)
Trunk Port
It is a port that serves to connect switches that need to be members of different VLANs together. And serves to pass traffic of multiple VLANs to distribute to other switches with port that is assigned to the same VLAN as the source switch, commonly known as Uplink Port or simply remember Trunk port is port. With multiple values running through, such as VLAN, multiple VLAN, or multiple Mac address values, forexample, to set a trunk port is – port that connects to other switches such as Uplink Port. – port that connects to the Router that serves Route Traffic between VLAN.
