Author: upravnik

Most corporate networks today use IP telephony. This means that the phones are connect to the same network and use the same cabling as other network devices, such as workstations or routers. Since offices usually have only a single UTP Read More …

Another VLAN tagging protocol is Inter-Switch Link (ISL). This protocol is Cisco proprietary, which means that, unlike 802.1Q, it can be used only between Cisco switches. It is considered to be deprecated, and newer Cisco switches don’t even support it. Read More …

IEEE 802.1Q is one of the VLAN tagging protocols supported by Cisco switches. This standard was created by the Institute of Electrical and Electronics Engineers (IEEE), so it an open standard and can be used on non-Cisco switches. To identify Read More …

To identify the VLAN a packet is belonging to, switches use tagging to assign a numerical value to each frame in a network with multiple VLANs. This is done to ensure that switches know out which ports to forward frames. Read More …

To configure an interface to be an access interface, the switchport mode acess interface command is used. This type of interface can be assigned only to a single VLAN. To configure a trunk interface, the switchport mode trunk interface command Read More …

By default, all ports on a switch are in the VLAN 1. We can verify that by typing the show vlan command from the IOS enable mode of a switch: In the picture above, you can see that all of Read More …

If you intend to use VLANs in your network, you will need to configure some ports on a switch as access ports and other as trunk ports. Here is a description each port type: access port – a port that Read More …

VLANs (Virtual LANs) are logical grouping of devices in the same broadcast domain. VLANs are usually configured on switches by placing some interfaces into one broadcast domain and some interfaces into another. Each VLAN acts as a subgroup of the Read More …

CSMA/CD (Carrier Sense Multiple Access with Collision Detection) helps hosts to decide when to send packets on a shared network segment and how to detect collisions if they occur. For example, in a hub network, two devices can send packets Read More …

Collision domain A collision domain is, as the name implies, the part of a network where packet collisions can occur. A collision occurs when two devices send a packet at the same time on the shared network segment. The packets Read More …