stathis wrote

Hello,

 

I want to create vlans for security reasons, but allthough i am professional developer i have no experience on vlans. I have  read the background of vlans and i made some experiments, with no success. In order to debug the problem and develop some familiarity with vlans i built the following lab.

 

1. One computer connected to port 2, producing some icmp packets
2. One computer connected to port 1 with wireshark monitoring the traffic
3. TL-SG2008 as managed switch (the production switch will be T2600G-28MPS, but i cannot experiment on this)
   1. Mirroring both ingress and engress from port 2 to port 1
   2. I created a vlan with id 4
   3. port 2 has  pvid 4
   4. port 2 also is a tagged member of vlan 4

 

As a result, the icmp packets that monitored has no vlan tag. I understand that something basic is missing to my understanding, but i have no clue what is it.

 

Any suggestion will be appreciated.

 

Thanks in advance

Hi stathis

Generally the network adapter of Windows PC cannot identify the frame that carry VLAN tag. You also can see the article from wireshark. 

https://wiki.wireshark.org/CaptureSetup/VLAN

But I remember that the Windows PC also can capture the frame that carry VLAN tag when modify the registry of Windows. When forget modify which registry. 

So if you didn't see the vlan tag on wireshark, it doesn't mean that the VLAN tagged port must not take effect. 

Hi Andone

I am not using Windows, i am using Linux and my nic is able ta handle VLAN tags, i have seen them when i tested on Allied Telesys switch.

stathis wrote

Hi Andone

 

I am not using Windows, i am using Linux and my nic is able ta handle VLAN tags, i have seen them when i tested on Allied Telesys switch.

Hi stathis

My fault, if your PC supports VLAN tag, I think it's easy to test. Just let your PC to send the data that carry VLAN 4 tag. Connect the PC to the switch. Add the switch port to VLAN4 as tagged port. Set up the IP address for VLAN 4 on the switch.  Then use your PC to ping the switch and capture the packets.