What defines VLAN trunk modes: Unaware, C-port, S-port, and S-custom-port?
Answer:
For example, EX26262 series has four types of VLAN trunk modes (Unaware/ C-port/S-port/ S-custom-port).
| Ingress action | Egress action | |
| Unaware The function of Unaware can be used for 802.1Q in Q (double tag). | When the port received untagged frames, an untagged frame obtain a tag (based on PVID) and is forwarded. When the port received tagged frames,
| The TPID of frame transmitted by Unaware port will be set to 0x8100. The final status of the frame after egressing are also effected by Egress Rule. |
| C-port | When the port received untagged frames, an untagged frame obtain a tag (based on PVID) and is forwarded. When the port received tagged frames,
| The TPID of frame transmitted by C-port will be set to 0x8100. |
| S-port | When the port received untagged frames, an untagged frame obtain a tag (based on PVID) and is forwarded. When the port received tagged frames,
| The TPID of frame transmitted by S-port will be set to 0x88A8. |
| S-custom-port | When the port received untagged frames, an untagged frame obtain a tag (based on PVID) and is forwarded. When the port received tagged frames,
| The TPID of frame transmitted by S-custom-port will be set to a self-customized value, which can be set by the user using the column of Ethertype for Custom S-ports. |
Port type - Ingress sample (each arrow color represents its operate behavior to individual packet)
S-custom-port is used for user defined TPID. While Ethertype for Custom S-ports is configured to 8888, outgoing packet will bring with TPID 8888 tag.
