- Written by Bill Terrell
- Posted on December 24, 2024
- Updated on December 24, 2024
- 1586 Views
On 7280R/R2, "Configurable TPID" enables a TPID to be configured per switchport (default TPID on switchport is 0x8100). A packet is considered tagged (both from ingress and egress point of view) on an interface if and only if TPID of the outermost VLAN tag on the packet matches the TPID configured on the interface. Up to 3 distinct (non-default) TPID values may be recognized per chip.
- Written by Terence Hui
- Posted on December 16, 2021
- Updated on June 9, 2023
- 8965 Views
Source port filtering is enabled by default to prevent traffic from egressing out the same interface it ingressed on.
- Written by Alok Kumar
- Posted on February 7, 2024
- Updated on May 7, 2025
- 6626 Views
Dot1q (802.1Q) is a tunneling protocol that encapsulates traffic from multiple customer (c-tag) VLANs in an additional single outer service provider (s-tag) VLAN for transit across a larger network structure that includes traffic from all customers. Tunneling eliminates the service provider requirement that every VLAN be configured from multiple customers, avoiding overlapping address space issues.