> Chapter 4 - Authentication > Examples and Troubleshooting

Examples and Troubleshooting

This chapter provides an example of a FortiGate unit providing authenticated access to the Internet for both Windows network users and local users.

The following topics are included in this section:

Firewall authentication example
LDAP Dial-in using member-attribute example
RADIUS SSO example
Troubleshooting

Firewall authentication example

Example configuration

Overview

In this example, there is a Windows network connected to Port 2 on the FortiGate unit and another LAN, Network_1, connected to Port 3.

All Windows network users authenticate when they logon to their network. Members of the Engineering and Sales groups can access the Internet without entering their authentication credentials again. The example assumes that the Fortinet Single Sign On (FSSO) has already been installed and configured on the domain controller.

LAN users who belong to the Internet_users group can access the Internet after entering their username and password to authenticate. This example shows only two users, User1 is authenticated by a password stored on the FortiGate unit, User2 is authenticated on an external authentication server. Both of these users are referred to as local users because the user account is created on the FortiGate unit.

Creating a locally-authenticated user account

User1 is authenticated by a password stored on the FortiGate unit. It is very simple to create this type of account.

To create a local user - web-based manager:

Go to User & Device > User > User Definition and select Create New.
Follow the User Creation Wizard, entering the following information and then select Create:

User Type	Local User
User Name	User1
Password	hardtoguess
Email Address SMS	(optional)
Enable	Select.

To create a local user - CLI:

config user local

edit user1

set type password

set passwd hardtoguess

end

Creating a RADIUS-authenticated user account

To authenticate users using an external authentication server, you must first configure the FortiGate unit to access the server.

To configure the remote authentication server - web-based manager:

Go to User & Device > Authentication > RADIUS Servers and select Create New.
Enter the following information and select OK:

Name	OurRADIUSsrv
Primary Server Name/IP	10.11.101.15
Primary Server Secret	OurSecret
Authentication Scheme	Select Use Default Authentication Scheme.

To configure the remote authentication server - CLI:

config user radius

edit OurRADIUSsrv

set server 10.11.102.15

set secret OurSecret

set auth-type auto

end

Creation of the user account is similar to the locally-authenticated account, except that you specify the RADIUS authentication server instead of the user’s password.

To configure a remote user - web-based manager:

Go to User & Device > User > User Definition and select Create New.
Follow the User Creation Wizard, entering the following information and then select Create:

User Type	Remote RADIUS User
User Name	User2
RADIUS server	OurRADIUSsrv
Email Address SMS	(optional)
Enable	Select

To configure a remote user - CLI:

config user local

edit User2

set name User2

set type radius

set radius-server OurRADIUSsrv

end

Creating user groups

There are two user groups: an FSSO user group for FSSO users and a firewall user group for other users. It is not possible to combine these two types of users in the same user group.

Creating the FSSO user group

For this example, assume that FSSO has already been set up on the Windows network and that it uses Advanced mode, meaning that it uses LDAP to access user group information. You need to

configure LDAP access to the Windows AD global catalog
specify the collector agent that sends user logon information to the FortiGate unit
select Windows user groups to monitor
select and add the Engineering and Sales groups to an FSSO user group

To configure LDAP for FSSO - web-based manager:

Go to User & Device > Authentication > LDAP Servers and select Create New.
Enter the following information:

Name	ADserver
Server Name / IP	10.11.101.160
Distinguished Name	dc=office,dc=example,dc=com
Bind Type	Regular
User DN	cn=FSSO_Admin,cn=users,dc=office,dc=example,dc=com
Password	set_a_secure_password

Leave other fields at their default values.
Select OK.

To configure LDAP for FSSO - CLI"

config user ldap

edit "ADserver"

set server "10.11.101.160"

set dn "cn=users,dc=office,dc=example,dc=com"

set type regular

set username "cn=administrator,cn=users,dc=office,dc=example,dc=com"

set password set_a_secure_password

end

To specify the collector agent for FSSO - web-based manager

Go to User & Device > Authentication > Single Sign-On and select Create New.
Enter the following information:

Type	Fortinet Single Sign-On Agent
Name	WinGroups
Primary Agent IP/Name	10.11.101.160
Password	fortinet_canada
LDAP Server	ADserver

Select Apply & Refresh.

In a few minutes, the FortiGate unit downloads the list of user groups from the server.

To specify the collector agent for FSSO - CLI:

config user fsso

edit "WinGroups"

set ldap-server "ADserver"

set password ENC G7GQV7NEqilCM9jKmVmJJFVvhQ2+wtNEe9T0iYA5Sa+EqT2J8zhOrbkJFDr0RmY3c4LaoXdsoBczA1dONmcGfthTxxwGsigzGpbJdC71spFlQYtj

set server "10.11.101.160"

end

To create the FSSO_Internet-users user group - web-based manager:

Go to User & Device > User > User Groups and select Create New.
Enter the following information and then select OK:

Name	FSSO_Internet_users
Type	Fortinet Single Sign-On (FSSO)
Members	Engineering, Sales

To create the FSSO_Internet-users user group - CLI:

config user group

edit FSSO_Internet_users

set group-type fsso-service

set member CN=Engineering,cn=users,dc=office,dc=example,dc=com CN=Sales,cn=users,dc=office,dc=example,dc=com

end

Creating the Firewall user group

The non-FSSO users need a user group too. In this example, only two users are shown, but additional members can be added easily.

To create the firewall user group - web-based manager:

Go to User & Device > User > User Groups and select Create New.
Enter the following information and then select OK:

Name	Internet_users
Type	Firewall
Members	User1, User2

To create the firewall user group - CLI:

config user group

edit Internet_users

set group-type firewall

set member User1 User2

end

Defining policy addresses

Go to Policy & Objects > Objects > Addresses.
Create the following addresses:

Address Name	Internal_net
Type	Subnet
Subnet / IP Range	10.11.102.0/24
Interface	Port 3

Address Name	Windows_net
Type	Subnet
Subnet / IP Range	10.11.101.0/24
Interface	Port 2

Creating security policies

Two security policies are needed: one for firewall group who connect through port3 and one for FSSO group who connect through port2.

To create a security policy for FSSO authentication - web-based manager:

Go to Policy & Objects > Policy > IPv4 and select Create New.
Enter the following information:

Incoming Interface	Port2
Source Address	Windows_net
Source User(s)	FSSO_Internet_users
Outgoing Interface	Port1
Destination Address	all
Schedule	always
Service	ALL
NAT	ON
Security Profiles	Optionally, enable security profiles.

Select OK.

To create a security policy for FSSO authentication - CLI:

config firewall policy

edit 0

set srcintf port2

set dstintf port1

set srcaddr Windows_net

set dstaddr all

set action accept

set groups FSSO_Internet_users

set schedule always

set service ANY

set nat enable

end

To create a security policy for local user authentication - web-based manager

Go to Policy & Objects > Policy > IPv4 and select Create New.
Enter the following information:

Incoming Interface	Port3
Source Address	Internal_net
Source User(s)	Internet_users
Outgoing Interface	Port1
Destination Address	all
Schedule	always
Service	ALL
NAT	ON
Security Profiles	Optionally, enable security profiles.

Select OK.

To create a security policy for local user authentication - CLI

config firewall policy

edit 0

set srcintf port3

set dstintf port1

set srcaddr internal_net

set dstaddr all

set action accept

set schedule always

set groups Internet_users

set service ANY

set nat enable

end

LDAP Dial-in using member-attribute example

In this example, users defined in MicroSoft Windows Active Directory (AD) are allowed to set up a VPN connection simply based on an attribute that is set to TRUE, instead of based on their user group. In AD the "Allow Dialin" property is activated in the user properties, and this sets the msNPAllowDialin attribute to "TRUE".

This same procedure can be used for other member attributes, as your system requires.

To accomplish this with a FortiGate unit, member-attribute must be set. This can only be accomplished through the CLI - the option is not available through the web-based manager.

Before configuring the FortiGate unit, ensure the AD server has the msNPAllowDialin attribute set to "TRUE" for the users in question. If not, those users will not be able to authenticate.

To configure user LDAP member-attribute settings - CLI:

config user ldap

edit "ldap_server"

set server "192.168.201.3"

set cnid "sAMAccountName"

set dn "DC=fortilabanz,DC=com,DC=au"

set type regular

set username "fortigate@sample.com"

set password ******

set member-attr "msNPAllowDialin"

end

To configure LDAP group settings - CLI:

config user group

edit "ldap_grp"

set member "ldap"

config match

edit 1

set server-name "ldap"

set group-name "TRUE"

end

Once these settings are in place, users that are a member of the ldap user group will be able to authenticate.

To ensure your settings are correct, here is the sample output from a diag debug command that shows the authentication process.

When the "Allow Dial-in" attribute is set to "TRUE" the following will likely be in the output:

get_member_of_groups-Get the memberOf groups.

get_member_of_groups- attr='msNPAllowDialin', found 1 values

get_member_of_groups-val[0]='TRUE'

fnbamd_ldap_get_result-Auth accepted

fnbamd_ldap_get_result-Going to DONE state res=0

fnbamd_auth_poll_ldap-Result for ldap svr 192.168.201.3 is SUCCESS

fnbamd_auth_poll_ldap-Passed group matching

If the attribute is not set but it is expected, the following will likely be in the output:

get_member_of_groups-Get the memberOf groups.

get_member_of_groups- attr='msNPAllowDialin', found 1 values

get_member_of_groups-val[0]='FALSE'

fnbamd_ldap_get_result-Auth accepted

fnbamd_ldap_get_result-Going to DONE state res=0

fnbamd_auth_poll_ldap-Result for ldap svr 192.168.201.3 is SUCCESS

fnbamd_auth_poll_ldap-Failed group matching

The only difference between these two outputs is the last line which is either passed or failed based on if the member-attribute is set to the expected value or not.

RADIUS SSO example

A common RADIUS SSO topology involves a medium sized company network of users connecting to the Internet through the FortiGate unit, and authenticating with a RADIUS server. RADIUS SSO authentication was selected because it is fast and relatively easy to configure.

This section includes:

Assumptions
Topology
Configuring RADIUS
Configuring FortiGate regular and RADIUS SSO security policies
Testing

Assumptions

VDOMs are not enabled
The admin super_admin administrator account will be used for all FortiGate unit configuration.
Any other devices on the network do not affect the topology of this example, and therefore are not included.
Anywhere settings are not described, they are assumed to be default values.
A RADIUS server is installed on a server or FortiAuthenticator unit and uses default attributes.
BGP is used for any dynamic routing.
Authentication event logging under Log&Report has been configured.

Topology

Example.com has an office with 20 users on the internal network. These users need access to the Internet to do their jobs. The office network is protected by a FortiGate-60C unit with access to the Internet through the wan1 interface, the user network on the internal interface, and all the servers are on the DMZ interface. This includes an Ubuntu Linux server running FreeRADIUS. For this example only two users will be configured — Pat Lee with an account name plee, or plee@example.com, and Kelly Green with an account name kgreen, or kgreen@example.com.

RADIUS SSO topology

Configuring RADIUS

Configuring RADIUS includes configuring the RADIUS server such as FreeRADIUS, a radius client on user’s computers, and configuring users in the system. For this example the two users will be Pat Lee, and Kelly Green. They belong to a group called exampledotcom_employees. When it is all configured, the RADIUS daemon needs to started.

The users have a RADIUS client installed on their PCs that allows them to authenticate through the RADIUS server.

FreeRADIUS can be found on the freeradius.org website. For any problems installing FreeRADIUS, see the FreeRADIUS documentation.

Configuring FortiGate interfaces

Before configuring the RADIUS SSO security policy, configure FortiGate interfaces. This includes defining a DHCP server for the internal network as this type of network typically uses DHCP. The wan1 and dmz interfaces are assigned static IP addresses and do not need a DHCP server.

FortiGate interfaces used in this example

Interface	Subnet	Act as DHCP Server	Devices
wan1	172.20.120.141	No	Internet Service Provider
dmz	10.11.101.100	No	Servers, including RADIUS server
internal	10.11.102.100	Yes: x.x.x.110-.250	Internal user network

To configure FortiGate interfaces - web-based manager:

Go to System > Network > Interfaces.
Select wan1 to edit.
Enter the following information and select OK.

Alias	Internet
Addressing Mode	Manual
IP/Network Mask	172.20.120.141/255.255.255.0
Administrative Access	HTTPS, SSH
Enable DHCP Server	Not selected
Comments	Internet
Administrative Status	Up

Select dmz to edit.
Enter the following information and select OK.

Alias	Servers
Addressing Mode	Manual
IP/Network Mask	10.11.101.100/255.255.255.0
Administrative Access	HTTPS, SSH, PING, SNMP
Enable DHCP Server	Not selected
Listen for RADIUS Accounting Messages	Select
Comments	Servers
Administrative Status	Up

Select internal to edit.
Enter the following information and select OK.

Alias	Internal network
Addressing Mode	Manual
IP/Network Mask	10.11.102.100/255.255.255.0
Administrative Access	HTTPS, SSH, PING
Enable DHCP Server	Select
Address Range	10.11.102.110 - 10.11.102.250
Netmask	255.255.255.0
Default Gateway	Same as Interface IP
DNS Server	Same as System DNS
Comments	Internal network
Administrative Status	Up

Configuring a RADIUS SSO Agent on the FortiGate unit

To create a RADIUS SSO agent:

Go to User & Device > Authentication > Single Sign-On and select Create New.
In Type, select RADIUS Single-Sign-On Agent.
Select Use RADIUS Shared Secret and enter the RADIUS server shared secret.
Select Send RADIUS Responses.
Select OK.
The Single Sign-On agent is named RSSO_Agent.

Creating a RADIUS SSO user group

To define a local user group for RADIUS SSO:

Go to User & Device > User > User Groups and select Create New.
Enter a Name for the user group.
In Type, select RADIUS Single Sign-On (RSSO).
In RADIUS Attribute Value, enter the name of the RADIUS user group this local user group represents.
Select OK.

Configuring FortiGate regular and RADIUS SSO security policies

With the RADIUS server and FortiGate interfaces configured, security policies can be configured. This includes both RADIUS SSO and regular policies, as well as addresses and address groups. All policies require NAT to be enabled.

Security policies required for RADIUS SSO

Seq. No.	From -> To	Type	Schedule	Description
1	internal -> wan1	RADIUS SSO	business hours	Authenticate outgoing user traffic.
2	internal -> wan1	regular	always	Allow essential network services and VoIP.
3	dmz -> wan1	regular	always	Allow servers to access Internet.
4	internal -> dmz	regular	always	Allow users to access servers.
5	any -> any	deny	always	Implicit policy denying all traffic that hasn’t been matched.

The RADIUS SSO policy must be placed at the top of the policy list so it is matched first. The only exception to this is if you have a policy to deny access to a list of banned users. In this case, that policy must go at the top so the RADIUS SSO does not mistakenly match a banned user or IP address.

This section includes:

Schedules, address groups, and services groups
Configuring regular security policies
Configuring RADIUS SSO security policy

Schedules, address groups, and services groups

This section lists the lists that need to be configured before security policies are created. Creating these lists is straight forward, so the essential information has been provided here but not step by step instructions. For more information on firewall related details, see

Schedules

Only one schedule needs to be configured — business_hours. This is a fairly standard Monday to Friday 8am to 5pm schedule, or whatever days and hours covers standard work hours at the company.

Address groups

The following address groups need to be configured before the security policies.

Address Group Name	Interface	Address range included
internal_network	internal	10.11.102.110 to 10.11.102.250
company_servers	dmz	10.11.101.110 to 10.11.101.250

Service groups

The following service groups need to be configured before the security policies. Note that the services listed are suggestions and may include more or less as required.

Service Group Name	Interface	Description of services to be included
essential_network_services	internal	Any network protocols required for normal network operation such as DNS, NTP, BGP.
essential_server_services	dmz	All the protocols required by the company servers such as BGP, HTTP, HTTPS, FTP, IMAP, POP3, SMTP, IKE, SQL, MYSQL, NTP, TRACEROUTE, SOCKs, and SNMP.
user_services	internal	Any protocols required by users HTTP, HTTP, FTP,

The following security policy configurations are basic and only include logging, and default AV and IPS.

Configuring regular security policies

Regular security policies allow or deny access for non-RADIUS SSO traffic. This is essential as there are network services—such as DNS, NTP, and FortiGuard—that require access to the Internet.

To configure regular security policies - web-based manager:

Go to Policy & Objects > Policy > IP4, and select Create New.
Enter the following information, and select OK.

Incoming Interface	Internal
Source Address	internal_network
Outgoing Interface	wan1
Destination Address	all
Schedule	always
Service	essential_network_services
Action	ACCEPT
NAT	ON
Security Profiles	ON: AntiVirus, IPS
Log Allowed Traffic	ON
Comments	Essential network services

Select Create New, enter the following information, and select OK.

Incoming Interface	dmz
Source Address	company_servers
Outgoing Interface	wan1
Destination Address	all
Schedule	always
Service	essential_server_services
Action	ACCEPT
NAT	ON
Security Profiles	ON: AntiVirus, IPS
Log Allowed Traffic	enable
Comments	Company servers accessing the Internet

Select Create New, enter the following information, and select OK.

Incoming Interface	Internal
Source Address	internal_network
Outgoing Interface	dmz
Destination Address	company_servers
Schedule	always
Service	all
Action	ACCEPT
NAT	ON
Security Profiles	ON: AntiVirus, IPS
Log Allowed Traffic	enable
Comments	Access company servers

Configuring RADIUS SSO security policy

The RADIUS SSO policy allows access for members of specific RADIUS groups.

To configure RADIUS SSO security policy:

Go to Policy & Objects > Policy > IP4.
Select Create New.
Enter the following information:

Incoming Interface	Internal
Source Address	internal_network
Source User(s)	Select the user groups you created for RSSO.
Outgoing Interface	wan1
Destination Address	all
Schedule	business_hours
Service	ALL
Action	ACCEPT
NAT	ON
Security Profiles	ON: AntiVirus, WebFilter, IPS, and Email Filter. In each case, select the default profile.

Select OK.
To ensure an RSSO-related policy is matched first, the policy should be placed higher in the security policy list than more general policies for the same interfaces.
Select OK.

Testing

Once configured, a user only needs to log on to their PC using their RADIUS account. After that when they attempt to access an Internet website, the FortiGate unit will use their session information to get their RADIUS information. Once the user is verified, they are allowed access to the website.

To test the configuration perform the following steps:

Have user 'plee' logon to their PC, and try to access an Internet website.
The FortiGate unit will contact the RADUS server for user plee’s information.
Once confirmed, plee will have access to the website.
Each step generates log entries that enable you to verify that each step was successful.
If a step is unsuccessful, confirm that your configuration is correct.

RADIUS SSO test

Troubleshooting

In the web-based manager, a good tool for troubleshooting is the packet counter column on the security policy page (Policy > Policy). This column displays the number of packets that have passed through this security policy. Its value when you are troubleshooting is that when you are testing your configuration (end to end connectivity, user authentication, policy use) watching the packet count for an increase confirms any other methods you may be using for troubleshooting. It provides the key of which policy is allowing the traffic, useful information if you expect a user to require authentication and it never happens. For more information about authentication security policies, see "Authentication in security policies".

This section addresses how to get more information from the CLI about users and user authentication attempts to help troubleshoot failed authentication attempts.

diag firewall iprope list

Shows the IP that the computer connected from. This is useful to confirm authorization and VPN settings.

diag firewall iprope clear

Clear all authorized users from the current list. Useful to force users to re-authenticate after system or group changes. However, this command may easily result in many users having to re-authenticate, so use carefully.

diag rsso query ip

diag rsso query rsso-key

Queries the RSSO database.

For more information on troubleshooting specific features, go to that section of this document. Most sections have troubleshooting information at the end of the section. In addition to that information, see the FortiOS Handbook Troubleshooting guide for general troubleshooting information.