Switchport trunk
A trunk is a port on a switch that is configured to carry traffic from multiple VLANs, and is typically implemented within the framework of an Ethernet network.
There are various types of Switchport trunk encapsulation, but the most commonly used one is the IEEE 802.3q standard. In this standard, each frame that traverses a trunk includes a VLAN tag that identifies the VLAN to which that particular frame belongs. The tag is placed within the Ethernet header.
Once that frame is received on the other end, the tag is read and removed, and the frame is placed on the appropriate VLAN.
Some additional concepts involved with trunks can be found at the following notes:
- Native VLANs and untagged frames
- VLANs - when a tagged frame arrives on an access port
- Private VLANs - across a trunk
- Switchport trunk configuration ignores access commands
- VLANs - 802.1Q tunneling (QinQ)
- DTP
- VoIP - Configuring a switch port for use with an IP phone
Links:
https://networklessons.com/switching/how-to-configure-trunk-on-cisco-catalyst-switch
Links to this page:
- DHCP snooping rate limiting best practice
- DTP - Sending of Frames
- DTP - best practice to disable
- DTP - how to disable
- DTP
- EtherChannel - prerequisites for bundling
- Ethernet administrative operational mode
- FHRP - which ports should you configure
- IPv6 RA Guard
- MAC address table - multiple entries of the same MAC address
- MAC address table
- Native VLANs and untagged frames
- Private VLANs - across a trunk
- QoS - CoS to DSCP and DSCP to CoS mapping
- QoS - marking
- QoS CoS vs DSCP
- SD-WAN - EVE-NG connection options
- STP Portfast Options
- Switch configuring a routed port
- Switchport - IEEE 802.1q
- Switchport - ISL
- Switchport access
- Switchport modes
- Switchport trunk configuration ignores access commands
- Switchport trunk encapsulation
- VLAN - Native VLAN best practices
- VLAN - Native VLAN on a router on a stick
- VLAN - QinQ troubleshooting
- VLAN - Trunk interfaces don't appear in `show vlan` output
- VLAN - VLAN IDs 0 and 4095
- VLAN SVI status
- VLAN Tag
- VLAN
- VLANs - 802.1Q tunneling (QinQ)
- VLANs - Vlans allowed and active in management domain
- VLANs - when a tagged frame arrives on an access port
- VTP operation over trunks
- VXLAN access trunk port
- VoIP - Configuring a switch port for use with an IP phone
- Wireless - WLC trunk connection to core
- Wireless AP FlexConnect mode switchport mode