What is trunk encapsulation?

Summary of Commands switchport trunk encapsulation negotiate sets the trunk interface to negotiate the encapsulation with the port on the other end. I stay away from this command and statically assign an encapsulation. switchport mode trunk administratively configures the port as a trunk.

What is a dot1q trunk?

IEEE 802.1Q (sometimes referred to as 1Q or DOT1Q) is a industry standards based implementation of carring traffic for multiple VLANs on a single trunking interface between two Ethernet switches. 802.1Q is for Ethernet networks only.

What is operational trunking encapsulation?

Operational Trunking Encapsulation: Operational Trunking Mode – Native : shows that end negotiation is not a trunk but an access port. Operational Trunking Mode -ISL/Dot1q: shows trunk has form what so ever you have configured.

What is the encapsulation dot1q command?

The switchport trunk encapsulation dot1q command tells the switch that the interface should use IEEE 802.1Q encapsulation on the frames when the interface is configured as a trunk. Basically 802.1Q inserts a VLAN tag on the frames. This contrasts with ISL that actually encapsulates the frames with an ISL frame.

What is difference between ISL and dot1q?

ISL is cisco proprietary and presently it is supported only by few high end switches only. Dot1Q is an IEEE’s open standard, which be used to create trunk connection between switches of different vendors. In ISL the original ethernet frame is not modified, it is encapsulated between an ISL header and an FCS.

What are the two Ethernet trunk encapsulation modes?

Trunking Overview Two trunking encapsulations are available on all Ethernet ports: Inter-Switch Link (ISL)—ISL is a Cisco-proprietary trunking encapsulation. 802.1Q—802.1Q is an industry-standard trunking encapsulation.

What is the difference between ISL and DOT1Q trunk?

What is ISL encapsulation?

ISL is Cisco’s VLAN encapsulation protocol and is supported only on some Cisco equipment over the Fast and Gigabit Ethernet links. It is offered as an alternative to the IEEE 802.1Q standard, a widely used VLAN tagging protocol, although the use of ISL for new sites is deprecated by Cisco.