LAN ports

 

LAN ports: Main features

Normally home routers incorporate one or more LAN ports, these LAN ports are the ones that belong to the local area network.

If you use IPv4 you will be within a class C subnet with mask 255.255.255.0, the most common subnets being 192.168.0.0/24, 192.168.1.0/24 or 192.168.2.0/24 although it depends on the manufacturers they may be others. At the configuration level, all computers on the LAN go to the Internet with the same public IPv4 thanks to NAT technology, therefore, they will have the same public IP to go to the Internet.The only difference between WLAN and LAN is the transmission medium. While in the LAN we make use of twisted pair cables, or fiber optic cables, in the WLAN we use the air as a transmission medium, that is, we use Wi-Fi technology normally.

As for the different standards that we can use in our routers, we currently use the Wi-Fi 4, Wi-Fi 5 standards, and if your router is of the latest generation, it is possible that it uses the new Wi-Fi 6 standard. Depending on the equipment we have, it can have WLAN in a single frequency band (normally 2.4GHz), we can have simultaneous double band (2.4GHz and 5Ghz) and we can even have equipment with simultaneous triple band (2.4GHz, 5GHz with channels « low "and 5GHz with" high "channels).

As you have seen, currently in routers we have three well differentiated interfaces, the WAN (Internet) interface, the LAN interface and the WLAN that belong to the home local area network. Of course, if we have a professional router such as the NETGEAR BR500 or the ASUS BRT-AC828 , we have the possibility of creating virtual LANs, that is, VLANs, to create several local subnets and segment the traffic lan health check.

In the case of having a more advanced home or professional network, it is completely necessary to segment the network by VLANs, which are basically virtual LANs, in which the frames are tagged to separate said subnets, and that we need a router to be able to intercommunicate them. VLANs allow us isolation, better control of everything that is happening in the local network, and also allow us to have a higher performance and avoid security problems. That is, for large networks where we have a large number of equipment, it is always necessary to segment into VLANs to provide the network with better security and performance. In addition, we will also have the possibility to provide professional APs with different VLANs, and in this way, have an SSID for each VLAN created.