VLAN question from Boson
BennyTheMan
Member Posts: 76 ■■■□□□□□□□
in CCNA & CCENT
I am confused about why an access port is not using 802.1q and supposedly will drop tagged frames. Anyone able to explain this? Please check out the screenshot.
Comments
-
PCTechLinc Member Posts: 646 ■■■■■■□□□□A switch strips the tag off the frame before it sends out the port. That is why an untagged frame is on the default VLAN.
Master of Business Administration in Information Technology Management - Western Governors University
Master of Science in Information Security and Assurance - Western Governors University
Bachelor of Science in Network Administration - Western Governors University
Associate of Applied Science x4 - Heald College -
BennyTheMan Member Posts: 76 ■■■□□□□□□□Thanks for the info. I'm honestly still confused, but I will continue to think it over.
-
Lunchbocks Member Posts: 319 ■■■■□□□□□□It drops all dot1q tagged traffic because the port is not a trunk. The first command sets the interface trunking type as dot1q, but only if trunking is configured. However, trunking is not configured. The "switchport mode access" command sets that interface as an access port, not a trunk port. An access port is a single vlan port, and is set to vlan 10 by the second command - "switchport access vlan 10".Hope this helps.Degree: Liberty University - B.S Computer Science (In Progress)
Current Certs: CCENT | MCTS | Network+
Currently Working On: Security+2020 Goals: CCNA, CCNP Security, Linux+ -
BennyTheMan Member Posts: 76 ■■■□□□□□□□I thought if an access port is sending or receiving traffic, that traffic should be tagged for that specific vlan (vlan 10) in this case. I understand that it is an access port. Thanks for helping.
-
Lunchbocks Member Posts: 319 ■■■■□□□□□□No, tags are only on trunk traffic and not needed for access ports. Access ports are single VLAN ports and the switch knows which VLANs are associated with each port.A trunk port can pass multiple VLANs, and when passing traffic for multiple VLANs it needs a way to keep track of what VLAN each frame belongs to. So the trunk port adds the tag to each frame before putting it on the link. When the traffic reaches the next switch, the tag is removed and the traffic is forwarded to the correct interface port.Hope this helps.Degree: Liberty University - B.S Computer Science (In Progress)
Current Certs: CCENT | MCTS | Network+
Currently Working On: Security+2020 Goals: CCNA, CCNP Security, Linux+ -
BennyTheMan Member Posts: 76 ■■■□□□□□□□This is clear. Is this saying that the switch will remove the vlan tag once the traffic crosses the trunk before going down the access port to the host? I think I'm finally clear. Really appreciate it!!
Ben -
Lunchbocks Member Posts: 319 ■■■■□□□□□□It might actually be removed as it is going out the access port, but you have the concept correct now.Glad I could help.Degree: Liberty University - B.S Computer Science (In Progress)
Current Certs: CCENT | MCTS | Network+
Currently Working On: Security+2020 Goals: CCNA, CCNP Security, Linux+ -
BennyTheMan Member Posts: 76 ■■■□□□□□□□Awesome. Feels good to understand.
Thank you so much. On the grind to pass icnd2 before feb -
Lunchbocks Member Posts: 319 ■■■■□□□□□□My pleasure. Good luck on ICND2.
Degree: Liberty University - B.S Computer Science (In Progress)
Current Certs: CCENT | MCTS | Network+
Currently Working On: Security+2020 Goals: CCNA, CCNP Security, Linux+