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Tom416
Tom416
New Member
March 20, 2019
Question

(Basic?) VLAN Issues!

  • March 20, 2019
  • 1 reply
  • 5406 views

I have read a lot of the articles relating to this, watched videos, and talked with support but still can't get to the bottom of this problem.

 

I have a FortiGate-30E (running 6.0.2) and a Netgear Switch (GS724TPv2 ProSAFE 24-Port Gigabit Smart Managed Switch)  Both are supposedly 802.1q compliant. (?)

 

I am trying to setup 4 simple VLANs.

 

These 3:

10 - Main (main network, data, printers)

DHCP: 192.168.10.1 /24

 

20 - Guest (just for the Guest SSID network, FortiAP)

DHCP: 192.168.20.1 / 24

 

30 - Voice (for the Polycomm VoIP phones)

DHCP: 192.168.30.1 / 24

 

and this 1 just in case the Netgear switch needs this to function (?)

1 - Management

DHCP: 192.168.100.1 / 24

 

None of the VLAN networks need to talk to eachother (no inter-VLAN routing needed) just need to go out to the WAN/Internet.

 

The main LAN/Hardware switch interface in the Fortigate has all 4 ports as members. It has the address 192.168.1.1

Underneath are the 4 VLAN interfaces, with their DHCP enabled.

 

Under IPv4 Policy, I have simple policies for each one that allow them to go out to the WAN.

 

I have port 1 of the Fortigate connected to port 1 of the Netgear switch. I would like this to be the Trunk port and have all VLAN traffic go through this one cable.

 

On the Netgear switch, I created the exact same VLAN IDs. I have port 1 tagged for all of them (10, 20, 30) and 1 as untagged, otherwise I lose communication.

 

Everything plugged into the router or switch gets an IP of 192.168.1.x (LAN interface)  - I don't even wan to use that subnet. I started off with that LAN interface DHCP disabled, thinking everything plugged in would be a member either VLAN 10, 20, or 30. But then nothing was getting an IP, and to communicate with anything I had to type in Manual IPs that LAN range, so I enabled DHCP and the switch gets 192.168.1.2, and anything plugged in anywhere is on that subnet.

 

As a simple test, I plugged in a Mac Mini (VLAN unaware) to port 24 of the Netgear switch. I would like to be on VLAN 10, and get a .10.x IP (not .1.x) I made port 24 a member of VLAN 10 / untagged. And I set the PVID from 1 to 10 to force incoming data on the switch to get tagged with 10. As soon as I change the PVID from 1 to anything else I lose communication. That Mac Mini ethernet port goes red and eventually gets a 169 self assigned IP. If I switch the PVID back to 1, it gets the LAN interface IP. I've tried a lot of combinations but nothing works. It's either 192.168.1.x or no communication.

 

I have been on the phone with Fortinet support, screenshared in, and they said everything looks good it must be the switch.

I have been on the phone with Netgear support (for hours, experimenting), screenshared in, and they said everything looks good it must be the router.

 

Ahhh!

 

1) How the hell can I get this working? What am I doing wrong?

2) Should I have created that Managment VLAN #1 ?

3) Do I need to use a VDOM? (not really sure what that is)

 

As you may notice, I'm not a VLAN expert and I don't really use the CLI.

The forti support did a sniff cmd on 67 and 68 and the traffic was not a part of any VLAN.

 

Please let me know if you need any other details in order to solve this. I am hoping to get this working today and will reply quickly.

 

Many thanks for the help!

Tom

 

 

 

 

 

    1 reply

    Toshi_Esumi
    SuperUser
    Toshi_Esumi
    SuperUser
    March 20, 2019

    I see one questionable part in this description. You said for vlans (1, 10, 20, 30) in addition to 192.168.1.0/24 (FGT's default untagged subnet) but also said vlan1 (192.168.100.0/24) is untagged, which is not possible.

    sw2090
    SuperUser
    sw2090
    SuperUser
    March 27, 2019

    FGT 192.168.1.0/24 untagged per default. 

    FGT does not change your vlan tagging at all (i.e. FGT Vlan Ports/INterface are always tagged).

    You wrote your ports on the netgear switch are tagged too.

    This means all traffic that does not already have vlan tag and comes to the netgear will get vlan tag 1 and "fall" into the FGT's default subnet. That I suppose is why you are getting 192.168.1.x dhcp ips.

    If you want to connect to one vlan either your client has to do the tagging or the port must be untagged in that vlan on the switch or you would have some device between client and switch which does that (this is what my accesspoints do here e.g.).

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