What does Switchport trunk encapsulation dot1q mean?

switchport trunk encapsulation dot1q sets the encapsulation mode of the trunk interface to the industry standard 802.1Q. switchport trunk encapsulation isl sets the encapsulation mode of the trunk interface to proprietary ISL. switchport mode trunk administratively configures the port as a trunk.

What is encapsulation dot1q command?

Router(config-subif)# encapsulation dot1q 1. Enables IEEE 802.1Q encapsulation of traffic on a specified subinterface in VLANs, and defaults the associated VLAN as a native VLAN. Step 3. Router(config-subif)# bridge-group bridge-group. Assigns each network interface to a bridge group.

What is Switchport trunk encapsulation?

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 802.1 Q trunking?

VLAN Trunking (802.1Q) allows physical network interfaces in a computing environment to be shared, or multi-homed. Network devices on the network then only interact with packets that have the correct tags. This allows multiple different logical networks to run on the same cable and switch infrastructure.

Is native VLAN allowed on trunk?

All VLAN IDs are allowed on each trunk. However, you can remove VLANs from this inclusive list to prevent traffic from the specified VLANs from passing over the trunk. You can add any specific VLANs later that you may want the trunk to carry traffic for back to the list.

What is 802.1Q trunking?

What is 802.1Q used for?

802.1Q tunneling enables service providers to use a single VLAN to support customers who have multiple VLANs, while preserving customer VLAN IDs and keeping traffic in different customer VLANs segregated. A port configured to support 802.1Q tunneling is called a tunnel port.

What is the difference between an access port and a trunk port?

An access port is a connection on a switch that transmits data to and from a specific VLAN. A trunk port allows you to send all those signals for each switch or router across a single trunk link. In contrast to an access port, a trunk port must use tagging in order to allow signals to get to the correct endpoint.

Does Switchport mode trunk allow all VLANs?

The all option in the switchport trunk allowed vlan command means all VLANs, so you can use it to reset the switch to its original default setting (permitting all VLANs on the trunk).

What is the purpose of 802.1Q tagging?

The 802.1Q tagging protocol allows the Ethernet frame size to increase by four bytes to a range of 68 to 1522 bytes. This size increase is due to the insertion of a four-byte VLAN tag into the frame. The tags, which include a VLAN Identifier (VID), are attached to each Ethernet frame by MAC address.

Is native VLAN needed?

In order to configure native VLAN, switch port trunk native VLAN command is used. Native VLANs are recognized if they are not tagged to any trunks. It is not necessary to have native VLAN on the trunk.