NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
"Advanced Engineering Certification - Wired Module 14": Multiple VLAN untagged???
Hello,
in Netgear Academy, "Advanced Engineering Certification - Wired", Module 14, ports are untagged in VLAN 1; at 06:20, some ports are added untagged to VLAN 10, too.
I could only replicate this when the port is in General Mode, not in Trunked or Access mode.
I am sorry if this is a newbie question.
From what I understand,
* every port can sensefully only have one VLAN untagged, the rest has to be tagged, as untagged denotes the direct VLAN untagged packets can be sent to. Please correct me if I am wrong here.
* "General" mode is kind of an "Auto" mode where the port itself decides whether it should act "Access" or "Trunked", so if I configure a port, I understand it that this configuration should work either in "Access" or in "Trunked, whichever is the actual mode I am working in?
So, this behaviour opens a lot of questions, namely which is the "real" untagged VLAN, and how it could be configured as "untagged" in multiple VLAN.
Note: As I am using devices I have at work that could be spared, I am using a M4250-10G2XF-PoE++, not the Netgear M4350-36X4V the learning video uses. However, regardless, I could replicate the behaviour of the switch in the tutorial video; and to me, there still is no sense in multiple VLAN being "untagged" for a single port.
Could perhaps somebody point me to sources where I can research this, or help out here?
Thanks, and greetings from the Franco-German borderlands,
Yours
Ralf
1 Reply
From what I understand,
* every port can sensefully only have one VLAN untagged, the rest has to be tagged, as untagged denotes the direct VLAN untagged packets can be sent to.Hallo Rolf,
Perfecly correct.* "General" mode is kind of an "Auto" mode where the port itself decides whether it should act "Access" or "Trunked", so if I configure a port, I understand it that this configuration should work either in "Access" or in "Trunked, whichever is the actual mode I am working in?
Take the predefined modes as "macros" for programming the switch ASIC.
From the good old RT*M:
---------
In the Switchport Mode list, select one of the following:
- Access. This mode is suitable for ports connected to end stations or end users. Access ports participate in only one VLAN. They accept both tagged and untagged packets, but always transmit untagged packets.
- Trunk. This mode is intended for ports that are connected to other switches. Trunk ports can participate in multiple VLANs and accept both tagged and untagged packets.
- General. This mode enables custom configuration of a port. You configure the general port VLAN attributes, such as membership, PVID, tagging, ingress filter, and so on, using the settings on the Port Configuration page. By default, all ports are initially configured in General mode.
- Host. This mode is used for private VLAN configuration.
- Promiscuous. This mode is used for private VLAN configuration.
----------
However, regardless, I could replicate the behaviour of the switch in the tutorial video;
Have to look-up that video again - so not sure what behaviour they what they want to show or proof there.
Please try to explain in a few words here.Kind of an assymetric VLAN config probably?
and to me, there still is no sense in multiple VLAN being "untagged" for a single port.
Same for me. Can only suggest to stay far away from such configs - unless there is a specific, documented use case.
Thanks, and greetings from the Franco-German borderlands,
Grüsse aus der Schweiz
-Kurt
NETGEAR Academy
Boost your skills with the Netgear Academy - Get trained, certified and stay ahead with the latest Netgear technology!
Join Us!
