View original (French)

VLAN tagged are not communicating

Marwerick -  
brupala Posted messages 111142 Registration date   Status Member Last intervention   -
Hello,

I've hit a bit of a wall for the last two days and I really need some help because apparently, something is eluding me.

I have two D-Link switches, a 1210-24 and a 1210-20.
I have configured two VLANs on each switch. One VLAN "Telephone" and one VLAN "Intranet".

On the 1210-20, I tagged port 15 for both VLANs, which connects to port 21 on the 1210-24, also tagged for both VLANs.

When I connect two machines to the Intranet VLAN, the connection works, and the ping goes through without any issues.
However, when I connect the same two machines to the Telephone VLAN, the connection fails. The ping does not go through.

From what I tested, the ping can reach both switches, regardless of the machine used, but it's impossible to connect to the other machine.

I tried making the VLANs symmetrical and asymmetrical. I also tried creating a third VLAN to put all the Intranet devices in so as not to go through the default VLAN. I tried enabling/disabling the Voice VLAN (just in case)... But now, I'm lost. :-)

If a kind soul has any help to offer, I would be grateful.

Thank you in advance.

1 answer

  1.
    brupala Posted messages 111142 Registration date   Status Member Last intervention   14 442
     
    Hi,
    does the intranet VLAN other than the default VLAN (1) still work?
    Are the IP addresses fixed on your PCs?

    From what I've tested, the ping can reach both switches, no matter which machine is used, but it's impossible to connect to the other machine.
    What do you think about that?
    What are asymmetric VLANs?

    --
    and ... There you go!
    0
    1. Marwerick
       
      Exactly the same issue when changing the intranet VLAN. Intranet works, Telephone does not work.
      Yes, the IPs are fixed. In 192.168.1.X/24 (I also tried with 10.X.X.X/8)

      I noticed this while doing some pings, actually. Since there are only the two switches between the machines, I simply pinged the two one after the other. Each time, I get a response.

      To be honest, I didn't really see the difference between symmetric and asymmetric. But since the option was available, I thought I had nothing to lose by trying to enable it.

      For your information, the IPs I'm using:
      192.168.1.35 for the 1210-20
      192.168.1.246 for the 1210-24
      192.168.1.36 for machine1
      192.168.1.37 for machine2
      0
    2. brupala Posted messages 111142 Registration date   Status Member Last intervention   14 442 > Marwerick
       
      Never heard of asymmetric VLANs...
      or it means tagged in one direction only, tags added on the output but removed on the input... that could exist.
      Is the management VLAN of the switches one of those two VLANs or a specific one?
      Be careful, if you change it, you might end up getting locked out ;-)
      Whatever the VLAN, do you always ping both switches?
      What is the default VLAN on your trunk ports (the ports that connect the two switches)?
      0
    3. Marwerick
       
      I haven't configured a management VLAN, in order to access the configuration from any machine. (This is only temporary, of course)
      And yes, regardless of the VLAN, the ping always goes through.
      I tried setting both VLANs as the default on the trunk port, but there was no change. Currently, I have left it on the intranet VLAN.
      0
    4. brupala Posted messages 111142 Registration date   Status Member Last intervention   14 442 > Marwerick
       
      If you set the phone VLAN as the default VLAN on the trunks, isn't it better for pinging through it?
      As far as I can see, I would say that you are only using the default VLAN (the one for management)
      Don't you have a port type to define (access, auto, phone, trunk, etc.) as well?
      0
    5. Marwerick
       
      No change by modifying the default VLAN of the trunk link. I left it on the Telephone VLAN, just in case.

      I set all the ports related to the Intranet VLAN as untagged (access mode on Cisco, it seems?) except the trunk port, of course.
      The same goes for the Telephone VLAN.

      To verify, I just set up the management VLAN. So that works. When I put it on the Intranet VLAN, only the machines on the intranet can access it and if I put it on the Telephone VLAN, it's the opposite.
      Still, no change in terms of the connection. And it’s not an issue with my machines, since on the Intranet VLAN, they can communicate with each other.
      0