Trunk is a technology that bundles multiple physical interfaces into a single logical interface. This logical interface is called a trunk interface, and each bundled physical interface is called a member interface.
Trunk technology helps increase bandwidth, enhance reliability, and carry out load balancing.
Without trunk technology, the transmission rate between two network devices connected by a 100 Mbit/s Ethernet twisted pair cable can only reach 100 Mbit/s. To obtain a higher transmission rate, you must change the transmission media or upgrade the network to a Gigabit Ethernet, which is costly to small- and medium- sized enterprises and schools.
Trunk technology provides an economical solution. For example, a trunk interface with three 100 Mbit/s member interfaces working in full-duplex mode can provide a maximum bandwidth of 300 Mbit/s.
This feature offers the following benefits:
Improved link reliability through traffic load balancing