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VLAN1 and GS108Ev3

NasKar
Aspirant

VLAN1 and GS108Ev3

I have a few Netgear GS108Ev3 switch connected together with tagged ports.

1) Is it ok to turn off VLAN 1 on all the ports and untag the VLANs I want to come thru on each port?

2) Can I connect a Cisco switch to the GS108Ev3 on a port where all the VLANs are set to tagged? Passing all the VLANs to a trunk port on the Cisco?  Do I have to have VLAN 1 active for this to work?

 

Model: GS108Ev3|ProSafe 8 ports Gigabit Plus switch
Message 1 of 6
schumaku
Guru

Re: VLAN1 and GS108Ev3


@NasKar wrote:

I have a few Netgear GS108Ev3 switch connected together with tagged ports.


802.1q mode one might guess here.

 


@NasKar wrote:

1) Is it ok to turn off VLAN 1 on all the ports and untag the VLANs I want to come thru on each port?


Yes, of course. 

 


@NasKar wrote:

2) Can I connect a Cisco switch to the GS108Ev3 on a port where all the VLANs are set to tagged?


Sure, create all the VLANs required and configure the port (for the trunk) to be tagged.

 


@NasKar wrote:

Passing all the VLANs to a trunk port on the Cisco?


Done as per the above.

 


@NasKar wrote:

Do I have to have VLAN 1 active for this to work?


Definewhat you understand as "have VLAN 1 active".

 

 

Message 2 of 6
NasKar
Aspirant

Re: VLAN1 and GS108Ev3

 Thanks for the reply.  I didn't get a email that you responded. Sorry about the late reply.

 

I think I finally have it working.  Can ping on all the devices on VLAN 5 from the computer connected to Cisco switch on untagged port VLAN5.

The Native Vlan on the trunk port of the Cisco has to be VLAN5 and the PVIDs for all the ports on the netgear have to be on 5 as well.

 

So the PVID is equivalent to Cisco Native VLAN?

Message 3 of 6
schumaku
Guru

Re: VLAN1 and GS108Ev3


@NasKar wrote:

So the PVID is equivalent to Cisco Native VLAN?


Half of it. Netgear has some design allowing the config of asymmetrical VLANs (breaking the 802.1q common understandings). There are two controls affected: The setting of the port to (one on the 802.1q context!) [U]natagged VLAN participation defining which VLAN frames are flowing out of the switch untaggged, and the PIVD which does define the VLAN untagged incoming frames to the switch will be assigned to.  

Message 4 of 6
NasKar
Aspirant

Re: VLAN1 and GS108Ev3

Very confusing. Both switches are using the 802.1q standard.

1) My understanding is the native Vlan must match on both sides of the trunk of it to work.

2) it's best to not have any data going over the native vlan

 

Can you confirm if I'm setup correctly?  Vlan 99 will be the native vlan without data

on the Netgear GS108Ev3 with trunk on ports 1,2 and 6 and 3-5 and 7-8 untagged for VLAN 5.

             1  2  3  4  5  6  7  8

Vlan 1
Vlan 5   T  T  U  U  U  T U  U

Vlan10  T  T                T
Vlan 99 U  U              U


PVID    99 on ports 1,2,6 and 5 on ports 3,4,5,7,8

Cisco

On the trunk port select Native Vlan as 99 

If my setup is incorrect hopefully you can show me what corrections to make.

Message 5 of 6
schumaku
Guru

Re: VLAN1 and GS108Ev3

Appears you hang on with the decades old (Cisco!) problem (read implementaion issue and old old switch hardware limitation) for not using native VLAN1 which is still often mentioned as best policy all over the the net. It happened back then that the native VLAN 1 was leaking over different other VLANs. Later on, bad guys could use a untagged port to inject tagged frames...

 


@NasKar wrote:

Very confusing. Both switches are using the 802.1q standard.


Can't see any confusion. Untagged frames re untagged frames - these are not part of dotQ.

 


@NasKar wrote:

1) My understanding is the native Vlan must match on both sides of the trunk of it to work.


Best policy of course, to avoid errors and confusion. Technically you can run the VLAN AB on one switch, expose this as an untagged/PVID (native if you want) on port, and on the adjacent switch you can bring these frames to VLAN XY, by configuring the link port to use the VLAN AB untagged, and PVID AB. The untagged frames don't indicate any VLAN. This is sometimes done when merging businesses and networks FWIW.  On the other end of the switch feature scale, there is even VLAN translation available.

 


@NasKar wrote:

2) it's best to not have any data going over the native vlan


Just yet another policy or rule of thumb ...no real technical reason, just a legacy issue...

 


@NasKar wrote:

Can you confirm if I'm setup correctly?  Vlan 99 will be the native vlan without data

on the Netgear GS108Ev3 with trunk on ports 1,2 and 6 and 3-5 and 7-8 untagged for VLAN 5.

             1  2  3  4  5  6  7  8

Vlan 1
Vlan 5   T  T  U  U  U  T U  U

Vlan10  T  T                T
Vlan 99 U  U              U


PVID    99 on ports 1,2,6 and 5 on ports 3,4,5,7,8

Cisco

On the trunk port select Native Vlan as 99 

 


Perfectly fine.

 

So at this point would you mind to tell us what advantage you have from using VLAN 99 instead of VLAN 1 now for the native VLAN?

 

Message 6 of 6
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