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scerazy
Visitor III
September 29, 2011
Question

DHCP to VLAN Wifi AP

  • September 29, 2011
  • 13 replies
  • 8330 views
I have pretty simple setup, yet can not make it work. Linksys WAP200 AP with two SSID (SSID1 for default Vlan1 & SSID7 for Guest Vlan7) It connects to a switch gig port in trunk mode Allied Telesis AT8000 which in turn connects to a core AT SBx908 via fibre port (also in trunk mode) Then one gig port from SBx908 (same trunk mode) connects to port 1 on FT 200B which is in Vdom1 AP ---> AT8000 ---> x908 ---> FT200B FT200 has 2 Vdoms (root & Vdom1). On Vdom1 there is DHCP server (on Interface Name port 1) If I connect to SSID1 I get the DHCP from FT200B from DHCP server on port1 (mostly - as sometimes I do get it from the mail LAN on root Vdom, strange!) If I connect to SSID7 I get NO IP at all How do I need to configure the DHCP on FT200B, so it gives me the IP for SSID7 (Vlan7)? Thanks Seb

    13 replies

    Matthijs
    New Member
    September 30, 2011
    If you have connected a trunk to the FortiGate you will have at least 2 sub interfaces. 1) vlan 1 2) vlan 7 They have to be in a vdom. Then per subinterface you have to create a DHCP server service in the correct vdom where the interface is in. So you have to have 2 dhcp services.
    scerazy
    scerazyAuthor
    Visitor III
    September 30, 2011
    So I have the very config, yet on one SSID I get no IP ever (Vlan7) On Vlan1 I get IP from my main network 10.0.0x DHCP server (and NOT from FTG) Seb
    ede_pfau
    SuperUser
    SuperUser
    September 30, 2011
    VLAN1 is the default VLAN or ' straight' LAN. Whoever answers first to a DHCP request delivers first. It' s a bad idea to have 2 DHCP servers on the same LAN (or VLAN), you' re asking for trouble. So in your case: - remove the DHCP server on the FGT for VLAN1 - create a DHCP relay to your existing DHCP server - be sure that traffic can reach it! - connect a VLAN trunk with both VLAN1 and VLAN7 to the FGT ' port1' . Create a virtual interface with VLAN ID 7 on ' port1' . Create a DHCP server on that interface. - create policies to allow traffic from/to port1 and the new VLAN port. As port1 is part of VDOM1 you' ll have to setup all of this in this VDOM. If the other networks are on the root VDOM you need an inter-VDOM link and policies.
    scerazy
    scerazyAuthor
    Visitor III
    September 30, 2011
    Correct, it is the very exact config that I have Yet I receive NO IP address from Fortigate when connected to SSID bound to Vlan7 Create a virtual interface with VLAN ID 7 on ' port1' . Does this interface have to have IP? or port1 has an IP? If port1 has to have an IP (192.168.188.254) then the virtual interface will not accept 192.168.188.252 Seb
    ede_pfau
    SuperUser
    SuperUser
    September 30, 2011
    No, it won' t. Networks on different router ports MUST be non-overlapping. Just choose a different address like 192.168.222.0/24. And yes, the ports, VLAN or physical, need to have an IP address. This address should be set as the gateway for this subnet. If you run DHCP, put it in the config there. All of this sounds like you' re really inexperienced with basic network stuff. Which makes me wonder how you' ll cope with the more complicated stuff like firewalling or UTM. You can do two things about this: - hire a professional who knows what he' s doing - read up on the documentation. I' ve posted the link to http://docs.fortinet.com so often that I' m about to get cramps. Get the FortiOS Handbook and read it. There' s one chapter on ' Basic setup' which will help you get started.
    scerazy
    scerazyAuthor
    Visitor III
    September 30, 2011
    As to being inexperienced? Not necessary, you probably have guys doing this & only this day in day out I do the whole array of network stuff (mostly from A to Z) on my own And only have that many hours in a day for everything Most professionals I seen over the years can do ONE single thing, ask them something else & they fall apart (as it is way beyond what they do) Please do not tell me that having one subnet on Vlan, one on the port, another on Vdom link, another on root vdom, abother on Wan, another on IPsec, another on SSL VPN is not a complicated issue. if I had only to deal with Fortigate setup and nothing much else I would surely be a champ But thank you for your kind advice And I did read FortiOS handbook (in case) Seb
    ede_pfau
    SuperUser
    SuperUser
    September 30, 2011
    Well then, if you' ve read the Handbook and seen the examples then you should have noticed that you have to assign an IP address to an interface in order to create a route. And along those routes the traffic flows. But I guess we all have a lot of things to take care of; let' s not waste time in complaining. I surely didn' t mean to question your competence. But still I have the impression that your setup needs far more attention than can be delivered over the forum. I' m not really living around the corner but I surely know what I' m doing (as I' m doing it for my living). We haven' t started going into the Fortinet specific details yet. How far have you come with the hints from my first post? Is the DHCP server seeing requests at all? Is the line to port1/vlan-port def. a VLAN trunk? There are quite a few options why this doesn' t work.
    scerazy
    scerazyAuthor
    Visitor III
    September 30, 2011
    I re-read the Vlan chapter & I am sure it will be easy to get working once I really have time to do it fully Only to say that the examples in manual are rather rubbish (stating Internal interface IP address) I do not know the other models, but 200B does not have Internal interface, each physical port is its own interface, hence all routing, policy access etc must be done for it Especially policies are complicated (even if the are only logic based) to get it all flowing Thanks for your help Seb
    ede_pfau
    SuperUser
    SuperUser
    October 1, 2011
    I do not know the other models, but 200B does not have Internal interface, each physical port is its own interface, hence all routing, policy access etc must be done for it
    The FGT-200B comes per default with 8 ports combined into a switch - the interface is called ' switch' . On the contrary, if you need as many physical ports you have to break up the switch before doing anything else, i.e. before creating policies or address objects tied to the switch interface. Maybe you should have a look into the concept of a ' zone' which Fortinet offers to reduce complexity. You put multiple interfaces into a zone and from then on only deal with the zone. For example, you have several VPN tunnels defined in interface-mode and all are handled in the same way, policy-wise. A zone ' VPNs' would reduce the number of policies 1:n. The difference between a switch-interface and a zone is that zones are handled by CPU. One other difference is that a switch-interface shares Layer 2 broadcasts - you can put a physical port and a WLAN port into one switch-interface and thus have the same broadcast domain for both ports.
    scerazy
    scerazyAuthor
    Visitor III
    October 6, 2011
    Sure, switch was the first thing I removed Yes I do use Zone for my dual Internet balanced And I did also employ the professional Result ... I am as far as I ever was (maybe just a bit closer) to my goal So the professional on this occasion helped me only in spiritual way (stating that it should just work) Which is rather simple (I think) 2 vdoms - root & test vlan to vdom test (from Vlan configured AP via vlan trunk across switches to FTG) connectivity from vdom test to internet via zone in root vdom connectivity from vdom test to selected servers in root vdom connectivity from vdom root to selected devices in vdom test Not much to ask, rather simple setup in my mind Yet me (and the professional) could NOT get the traffic: from vdom test to internet zone in root vdom to happen at all (it works fine from root vdom ofcourse) So I gave up & stuck different ADSL line on another port in vdom test (reconfiguring the routing ofcourse to reflect this new gateway) And the results were just fantastic!: could get fine to OpenDNS DNS servers & to Google & to WhatismyIP, but NOT ie. to bbc.co.uk -- even I could trace to bbc.co.uk just fine So browsing to some sites worked, for others did not (makes no sense at all) Just to make sure, the FW rule for testing was ALL to ALL ALLOW Also I could ping my selected root vdom based servers (as well as trace to), but NOT get to webserver on same machine as being pinged (and yes, rules are there to allow PING as well as HTTP /S) At least I must say it is fun when something behaves completely illogical. Not yet giving up completely, will be still trying... Seb