First blog post

Hii tr,

I am IT Networking Profession with Extensive experience in Wi-Fi and Security. Working with a leading security company as Sr.Wireless Expert and Field Support Engineer. My passion towards Wireless have driven me so far and I am pleased to introduce myself as a Wi-Fi Engineer.

Wireless Experts blogs and other Wi-Fi communities have always been so helpful in finding solutions for all my question ever. I am Very much excited and happy to share my thoughts and experience about Wireless and Security.


Disconnect User Network Access through Forti-Authenticator Usage profile


Goal:  Disconnect/Not to allow user network access after certain usage.



Configure your Fortigate/NAS to send User Accounting information to Forti-Authenticator after successful user authentication. In this case Forti-Authenticator is  used as Authentication server as well.

#Sample Radius configuration on Fortigate :

config user radius

edit “”

set server “”

set secret ENC     zMbdF/mNYBr5a4Cc3cP

set nas-ip

set acct-interim-interval 600

set radius-coa enable

config accounting-server

edit 1

set status enable

set server “”

set secret ENC   nGw/l5GCxHSymW3SnXGJKgmk

set port 1646



Note: Port 1646 is used for Accounting traffic on Fortigate and Forti-Authenticator.

Interim Acct and COA is enabled.


acct port



Make sure to enable Accounting monitor on the FAC interface that will be talking to NAS/Fortigate.




Enable to “Accept Accounting” on the radius client profile and support COA.



STEP 4 :

Usage profile for time or data is configured.



STEP 5 :

Usage profile can be applied to user/ user group /Device.


Remember to add the Radius Attribute  interim update set to 600 sec once.



After successful authentication and Receiving Radius Accounting information you get to see the sample like below.

Navigation:  Monitor->Radius Accounting



If FAC(Forti Authenticator) find the user crossed time/usage(data) limit , then it sends out a COA message to Fortigate and also disables the user at FAC.




User session state at Fortigate 

==> User Session before Disconnect/bounce from network

Alza-kvm21 # diagnose firewall auth list | grep -A5 “test1”, test1, captive FAC user
src_mac: 00:0c:29:xx:xx:xx
type: fw, id: 0, duration: 547, idled: 64
expire: 236, allow-idle: 300
flag(30): radius idle


==> User session after Disconnect/bounced from network.

Alza-kvm21 # diagnose firewall auth list | grep -A5 “test1”

Alza-kvm21 #



SMS Token Based Captive Portal Authentication with Forti Authenticator

Forti Authenticator is a Identity and Access Management system and very efficient when it comes for client Access Control Management. In this Blog post you will see how can you use the captive portal function on FAC for SMS Based Token Authentication. We integrate the FAC with Fortigate Firewall being NAS.

Token Authentication can be done using Hardware(Forti Hardware Token) or Soft Token(Fortinet Token Mobile) too. In this case we use SMS Gateway to deliver the token for users over SMS. I believe this could come effective for a Wireless Guest user Authentication with Token Code.


Step1:  Creating  wireless interface/ SSID and set the captive portal redirection URL to external portal landing page at Forti-Authenticator



Step2: You need to configure a Radius Server on fortigate Firewall for back end Authentication with Forti Authenticator.



Step3: On the fortigate Firewall you need to make sure HTTP or HTTPS/DNS allowed for the Guest user’s traffic to get successfully redirected to  captive portal page.



Step4: Now on the Forti-Authenticator you could configure the social login page with Guest account settings.

4.1 You need to enable Social Login page first.

4.2 You could then select the User Group to be placed for all the users through this portal.

4.3 Set  the Account expiration Hour for your Users

4.4 If you have multiple SMS Gateway Service then choose the one which you would like to be used. In this example, i have used Fortiguard Messaging service(Need to purchase the license)

Note: If you like to Give other Social Login access on the same page then you could enable FACEBOOK LOGIN , GOOGLE LOGIN etc. However you may need to configure the respected login key and secret setting for them to work.




Step 5.Setup your Radius client settings, in this case it will be your fortigate firewall.  You must use the same Shared Secret key you configured on “step-2” at fortigate firewall.

5.1 Enable  Social login portal  under radius client settings.



Step 6. After a successful user authentication you will see the user information captured as social login user.


7. You will get to see the following user Event on the Fortigate for the successful user login with Token.


8. Further on the FAC side you may be able to see the following user Events under logging and log access.



Hope the following blog post is helpful in setting up your FAC for SMS based Token Authentication.

Setting up Fortinet Remote VPN AP

FortiRU Wireless controllers support remote AP setup mostly from SD6.0 Onwords. You will have a remote AP configured at your small office/remote office or home that can be managed/Provisioned by WLC  sitting at Data Center. In this case the data communication between controller and AP goes over the internet which is secure by open VPN encryption.

Configuring VPN AP:

First step, is to install a SSL Certificate for WLC controller (VPN server certificate) to manage and authenticate the remote APs.

+Before Processing to import the signed SSL certificate for controller first install the trusted CA certificates.



+Similarly import all subordinate CA certificates(if any sub CA’s).


Create a certificate Signing request(csr) for Controller:

+Login to Controller, Go to Configuration ->Security-> Certificates -> Controller Certificates.


+Click on Add button (You can see a Certificate Add Popup), Fill in the Input Fields and click on Save.

+User can View CSR (select the radio button against the Pending CSR) and then Click View button or export the CSR by clicking Export Button

+Once the CSR is created, User can see Entry Created (showing the Type as Pending-CSR)

+Select the radio button against the Pending CSR, then click on Import Certificate Button



+User can see the Certificate Alias name, issued to, Issued By etc.




Step Two, Configuring Remote VPN AP and assigning a certificate for the VPN client.

i. Login to Controller, Go to Configuration -> Certificates -> AP Certificates and List of AP’s will be displayed, Make sure that the AP for which you are installing is Enabled and its Online.


ii. Select the radio button against the AP, then click on Create CSR Button
iii. A Create Signing Request – AP Certificate Popup will Appear
iv. Enter the Validity (in days) and then click Apply.


v. Click the Refresh Button, Once on Refresh, user can see CSR-Generation-in-Progress under User Req status.


vii. User can View CSR (select the radio button against the AP) and the Click View button or export the CSR by clicking Export Button


viii. Give the CSR File or the Contents to the CSR to the admin to get the Certificate and the CA Certificate
ix. Incase if the Certificates is issued by a different CA server, First install the CA Certificate as mentioned in “Trusted CA install section at the beginning .”.
x. Import the Certificate for the AP, by selecting the radio button against the AP and by clicking Import Button



xi. Once the Certificate is copied, user can see a message “Cert-Installation-In-Progress ” under user Req Status

xii. Once the Certificate is Installed, user can see “Cert-Installed” message under User Req Status


NOTE: AP must be on L3 connection(must assign IP)


Assigning the server certificate for the VPN server:

i. Login to Controller, Go to Configuration -> Certificates -> Controller Certificates
ii. Click on Application Button, A Popup will appear, select the certificate next to VPN Application and click save.


iii. A popup message will be displayed asking user to run reload-vpn command from CLI ( On running reload-vpn, selected certificate will be used by VPN Server) Forti-Ru gives this option to user, because if already all AP’s are connected using VPN, running reload-vpn will cause all VPN AP’s to reboot, Hence when there are no stations, the user can run reload-vpn.


Creating a VPN SERVER on Controller:

I. Login to Controller, Go to Configuration -> Security -> VPN Server
ii. Fill in VPN Server/IP Name, it should be Controller’s Publicly reachable IP address or the hostname (FQDN), also fill the port, default will be 1194, IP pool and subnet needs to be added.

vpn server


Finally, Adding the AP to VPN Group:

i. Login to Controller, Go to Configuration -> security -> VPN server -> VPN AP’s

ii. Select the AP’s that you want to add to the VPN Group and Click on next


iii. See the Column below Action required, if the status is “No Action Required“, Click activate, if there is any pending action, User need to finish the pending action before activating.


iv. Once User clicks Activate, Initially the VPN connectivity status will be disconnected, AP will go for reboot

v. Once the AP comes back, AP will connect back to controller in VPN mode and user can see the status as Connected under VPN Connectivity Status.



Troubleshooting command:

Controller level:

default(15)# show vpn-ap

default(15)# show vpn-server

default(15)# show vpn-ap <id>

default(15)# show ap-certificate <id>

default(15)# capture-packets -R ip.addr==x.x.x.x

+Run Capture packets command with filter as AP’s Real IP address, the communication between controller and AP should happen only on VPN port (in this case UDP port 1194)


AP Level:

ap 8> ip vpn show

Chromcast SSDP and mDNS Service Control on Fortinet Wireless Controllers

Service control feature on FortiRu Controller’s been there for quite some time now. This has been very effective in managing the mDNS traffic on wireless side. Once you enable this feature on the Wireless controller you could manage the mDNS traffic flow across VLANS and ESSIDS by creating Service control policy.

This works well for mDNS traffic control for Airprint ,Airplay, etc. There are some limitation in case of chromecast multicast traffic management when it comes managing SSDP traffic.

FortiRU controller don’t support SSDP service control across multiple VLANs from day one. While still this can work between ESSIDs within VLAN.

Reason, In your FortiRU controller’s :

                           SSDP forwarding happens on data path
                           mDNS forwarding happens on user space.

Since SSDP traffic doesn’t hit the user space the Service control policy don’t get applied.

A real world condition:  If you try use your Windows computer with chromecast you mostly will notice mDNS traffic used for discovery and mirroring. While on a iPad running YouTube application and you try to mirror that application you will see SSDP application used for discovery. So, this very well depends on Device/Application using SSDP ( udp dst port 1900) for discovery.

Following a Feature request, now from SD 8.4 General release onward it will be supported.


By default, on  FortiRU OS you will have apple service types available for service control while for chromecast you might need to create your own service types(FortiRu OS might be missing what exactly you want).

#Configuration on WLC controller is straight forward::

1.Enable service control

enable service control

2.Confirm that your interested service types are available on your WLC controller for service control

service type

3.SC-AP Group creation

sc ap group

4. Publisher and subscriber User Group creation.

user group

5. Finally Policy creation:


To debug Service control issue on WLC-Controller:

FortiMeruXXX(15)# sup-cli
FortiMeruXXX] tr ServiceMgr ffffffff

FortiMeruXXX] trace on (turn on the trace)

Once the issue is captured turn it OFF.

FortiMeruXXX] trace off (turn OFF the trace)

To debug on AP side:

AP level : (check the client connected AP and run the trace on the AP)

Conn ap  

ap X> trace on 
Real-time trace display enabled for severity >= 0. 

Once the issue is captured turn it OFF. 

ap X> trace off 
Real-time trace display disabled. 


Internet Service DB (ISDB) on Fortigate

A  feature called Internet service DB(ISDB) is introduce on ForitOS. Using this feature you could write firewall policy and Route and ask Fortigate to take Necessary action based on the Application IP DB it has.

This feature was introduced in FortiOS v5.4 and above. NOTE: ISDB updates require active FortiCare support contact, no FortiGuard subscription required.

During FortiOS v5.2 days  you could create a firewall policy with FQDN to Block/Allow users based  website Hostname. However that is no more an option from v5.4 and above(not supported)

Blocking/allowing user access based on Public Application IP address is not a easy task. There will be dozens of IP address “Ex: Facebook an Google” and its not easy to manage the IP DB by Every one, While new IP address’s will always get added to this list.

So , You could now take advantage of this feature ISDB and manage the Dynamic changes of IP address.



>While running the following command will show you the available and updated signature DB on fortigate. And you should see ISDB also showing up there.

# diagnose autoupdate versions

>Inorder to list out the IPs address on DB for a particular Application (or)  can see through GUI also.

# diagnose firewall internet-service list 3604481

‘3604481’ is application ID for Github-Web.


NOTE: I have chosen Application GitHub just for my examples.

>FortiOS also lets you to create your own custom ISDB, this helps customer to manage their own list on top of what FortiOS is offering. You could list your custom object after you create one like below.

# diagnose firewall internet-service-custom list

List internet service in kernel(custom):
name=Git-custom, id=4294901760 flags=0x0 protocol=6 port=80-65535 1-65535
addr ip range(1): 200.X.X.X-200.X.X.X


>You could also Add more IP address that you feel ISDB missing for an application by just creating a custom object mentioning the master-service-id

# config firewall internet-service-custom

(internet-service~tom) #

(internet-service~tom) # show
config firewall internet-service-custom
edit “Git-custom”
set master-service-id 3604481
set comment “git”
config entry
edit 1
set protocol 6
config port-range
edit 1
set start-port 80
edit 2
set dst “x.x.x.x”


>You could create a firewall policy with Existing Internet service DB available or customer Internet service DB created while also doing route control.

github policy


FortiGate on SIP/ALG/Session Helper

If you are looking for some idea on change/tweak on fortigate for SIP/VoIP traffic,  I believe the below details could give help you a bit of insight on configuring Fortinet for your SIP/VoIP design. I know there are other Fortinet Experts who already shared some idea related to this Topic. This is just my version of the same and with some add-ons!!

When to use”session helper” && “Voip-ALG(Kernel mode)” && “Voip-ALG(Proxy mode)”??

Type of SIP VoIP design:

*Picture courtesy fortinet Voip Guide.

Peer to peer configuration

SIP proxy server configuration



SIP redirect server configuration


SIP registrar configuration

SIP with a FortiGate running Transparent Mode


SIP network with FortiGate running NAT/Route Mode:



Tweaking your Fortigate  based on your design requirements for SIP VoIP Traffic :

*SIP sessions using port 5060 accepted by a security policy that does not include a VoIP profile are processed by the “SIP session helper”.

*Session helper + Fortigate VoIP ALG mode “Kernel Mode” = SIP session offload, SDP conversion happens with RTP session pin hole

*Fortigate VoIP ALG mode “Proxy Mode”(ALG)  = More SIP ALG features /security features and explicit FW policy required.

*Fortigate VoIP ALG mode “kernel Mode” + Disable Session Helper = no SIP ALG on fortigate.


By default FortiOS uses the Proxy Mode SIP ALG for SIP traffic. If you want to use the SIP session helper you need to enter the following command:

config system settings

set default-voip-alg-mode kernel-helper-based


NOTE: Also remove SIP session helper profile under”config system session-helper”

In most cases you would want to use the SIP ALG since the SIP session helper provides limited functionality. However, the SIP session helper is available and can be useful for high-performance solutions where a high level of SIP security is not a requirement.


#Key Things you should understand#

*Controlling NAT for addresses in SDP lines
You can use the no-sdp-fixup option to control whether the Fortigate performs NAT on addresses in SDP lines in the SIP message body.

The no-sdp-fixup option is disabled by default and the FortiGate performs NAT on addresses in SDP lines. Enable this option if you don’t want the FortiGate to perform NAT on the addresses in SDP lines.

config voip profile

edit VoIP_Pro_1

config sip

set no-sdp-fixup enable




*How the SIP ALG performs NAT :

I see this as an important portion to understand atleast while working with fortigate firewalls.

NAT with SIP gets bit complex because of IP and Port Number used in SIP message Header and Bodies. When a SIP caller on private network calls the phone server or SIP phone on internet, the SIP ALG must translate the private network addresses to internet valid IP and port numbers. And when receiving the response message to the caller, the SIP ALG must translate back to valid private network address.

Additionally, the media stream generated by SIP session are independent SIP message and use different port numbers during media session. Based on the information in the SIP message the SIP ALG opens pinholes to accept media stream and perform port translation on media stream.

When SIP ALG receives an INVITE message, fortigate extracts information like port number and IP address and stores it in SIP Dialog table. This is similar to IP session table and this data is used for subsequent SIP message that are part of same call.

ALG then using the information in SDP field helps reserve port number and IP address for media session and create NAT mapping between ports in the SDP field. Normally SDP uses sequential ports for the RTP and RTCP channels and ALG provides consecutive even-odd ports.



Wi-Fi Now Conference Bangkok-2017

I recently got chance to attend the Wi-Fi Now conference held at Bangkok this year. Met some wonderful people in WiFi community.

Got engaged on discussion with latest WiFi deployments and its success stories.

How to meet customer demands with right solutions available in the market. Vendors gave some insight on how they are meeting customer demands already and what they can offer to meet the customer requirements and some Proof of success from POCs and production network.


At the same day, met some of my favorite wi-fi peers.


I was given a demo on iBWAVE WiFi Design Tool by  Sunder Arumugam and Swee Leong Sim

#My favorite features on  iBWAVE :

Advanced 3D modeling of the venue
Cable routing and costing
Complete bill of materials reporting
project proposal generation
Automatic link budget calculations


#Ekahau Folks

Met Brandon Biggs and Mark Winter from inTechnology Distribution

I was given a Demo on New Sidekick Tool and had some discussed on Single Channel planning with Ekahau Wi-Fi design Tool.


#Wi-FI Now CEO and chairman | Claus Hetting

Got chance to have a short conversation regarding the conference.


# CWNE and Board of Advisor | Ronald van Kleunen

I was able to catch-up with Ronald at Bangkok