AnyConnect Group Authentication With Cisco ISE and Downloadable ACLs (Part 1)

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KB ID 0001155 Dtd 09/02/16

Problem

To be honest it's probably a LOT easier to do this with Dynamic Access Policies, but hey, if you have ISE then why not use it for RADIUS, and let it deploy downloadable ACL's to your remote clients and give them different levels of access, based on their group membership.

I'm going to keep things simple, I will have a group for admins that can access anything, and a group for users that can only RDP to internal servers.

I always assume things will break, so I'm also going to create a local user on the ISE deployment, so if Active Directory is down I will have a user account I can use to gain full access in the event of an emergency.

Solution

In production you will have plenty of users, but to test Im going to create a test user, and a test admin user.

Cisco ISE AD Users

Then put those users in an appropriate Active Directory security group, (here I'm using VPN-Users and VPN-Admins).

Cisco ISE AD Groups

Now you will also need a 'Tunnel-Group and a matching Group-Policy on the ASA to map the user groups to. That way, when a user connects they can pick the appropriate tunnel group like so;

Cisco Tunnel Groups AnyConnect

Cisco Tunnel Groups Portal

So what I've done is setup AnyConnect and configured it properly, (see article below) then I've simply 'cloned' the tunnel group, and group policy to create a VPN-ADMIN and VPN-USERS tunnel-group ,and  a group-policy. So my ASA config is as follows;

1. Show run ip local pool

Petes-ASA# show run ip local pool
ip local pool ANYCONNECT-POOL 192.168.101.1-192.168.101.254 mask 255.255.255.0
Petes-ASA# 

2. Show Group-Policy

Petes-ASA# show run group-policy
group-policy GroupPolicy_ANYCONNECT-PROFILE internal
group-policy GroupPolicy_ANYCONNECT-PROFILE attributes
 wins-server none
 dns-server value 192.168.100.10
 vpn-tunnel-protocol ssl-client 
 split-tunnel-policy tunnelspecified
 split-tunnel-network-list value SPLIT-TUNNEL
 default-domain value petenetlive.com
 webvpn
  anyconnect profiles value PNL-Profile type user
group-policy VPN-ADMINS internal
group-policy VPN-ADMINS attributes
 wins-server none
 dns-server value 192.168.100.10
 vpn-tunnel-protocol ssl-client 
 split-tunnel-policy tunnelspecified
 split-tunnel-network-list value SPLIT-TUNNEL
 default-domain value petenetlive.com
 webvpn
  anyconnect profiles value PNL-Profile type user
group-policy VPN-USERS internal
group-policy VPN-USERS attributes
 wins-server none
 dns-server value 192.168.100.10
 vpn-tunnel-protocol ssl-client 
 split-tunnel-policy tunnelspecified
 split-tunnel-network-list value SPLIT-TUNNEL
 default-domain value petenetlive.com
 webvpn
  anyconnect profiles value PNL-Profile type user
Petes-ASA#  

Show Tunnel Groups

Petes-ASA# show run tunnel
tunnel-group ANYCONNECT-PROFILE type remote-access
tunnel-group ANYCONNECT-PROFILE general-attributes
 address-pool ANYCONNECT-POOL
 default-group-policy GroupPolicy_ANYCONNECT-PROFILE
tunnel-group ANYCONNECT-PROFILE webvpn-attributes
 group-alias ANYCONNECT-PROFILE enable
tunnel-group VPN-ADMINS type remote-access
tunnel-group VPN-ADMINS general-attributes
 address-pool ANYCONNECT-POOL
 default-group-policy VPN-ADMINS
tunnel-group VPN-ADMINS webvpn-attributes
 group-alias VPN-ADMINS enable
tunnel-group VPN-USERS type remote-access
tunnel-group VPN-USERS general-attributes
 address-pool ANYCONNECT-POOL
 default-group-policy VPN-USERS
tunnel-group VPN-USERS webvpn-attributes
 group-alias VPN-USERS enable
Petes-ASA# 

Create a Local Admin Group in Cisco ISE

On your Cisco ISE Deployment > Identity Management > Groups > Add.

Add AD groups to ISE

Give the group a name and optional description > Save.

Local ISE Admin Group

To create an admin user > Administration > Identity Management > Identities > Add.

ISE Identity Management

Create the new admin user > set the password > add the user to the group you create above.

ISE Local Admin

Adding Domain Groups To Cisco ISE

I'm assuming you have joined ISE toActive Directory > To check Administration > Identity Management > External Identity Sources > Ensure the domain is joined and operational.

ISE External Identity Source

Groups > Add.

AD Groups in Cisco ISE

Locate and add the groups you created above.

00011

Add An Active Directory Identity Source Sequence

We need to authenticate against our AD, but we want it to fail back to the ISE local database, (for our local admin). To do that we use and identity source sequence. Administration > Identity Management > Identity Source Sequence > Add.

00012

Give the sequence a name and add your AD and Internal Users.

00013

MAKE SURE you select 'Treat as if the user was not found and proceed to the next store in the sequence' > Submit.

00014

Add Cisco ASA to Cisco ISE as a RADIUS Device.

Administration > Network Resources  > Network Device Groups > All Device Types > Add.

00015

Add a device GROUP for your ASA(s) > Submit.

00016

Administration > Network Resources  > Network Devices > Add.

00017

Add in the ASA > Provide its IP address, and add it to the group you created above > Set a RADIUS Shared Secret > Submit.

00018

The shared secret must be the same on the ASA in the AAA config, like so;

Petes-ASA(config)# aaa-server Cisco-ISE protocol radius
Petes-ASA(config-aaa-server-group)# aaa-server Cisco-ISE host 192.168.100.11
Petes-ASA(config-aaa-server-host)# key 123456
Petes-ASA(config-aaa-server-host)# radius-common-pw 123456 
Petes-ASA(config-aaa-server-host)# exit
Petes-ASA(config)# 

Cisco ISE Create Downloadable Access Control Lists DACL

Policy > Policy Elements > Results > Authorisation > Downloadable ACL's > Add.

00019

Create an ACL for our VPN-USER group, that will only allow RDP (TCP 3389) > Submit.

00020

Repeat the process to create an ACL that allows everything, (for our VPN-ADMINS) > Submit.

00021

Cisco ISE Create Authorisation Profiles

Policy > Policy Elements > Results > Authorisation > Authorisation Profiles > Add.

00022

Create a profile for VPN-ADMINS > Set the correct DACL.

00023

Set the advanced attributes > Change to RADIUS.

00024

Class-25

00025

Set the OU to equal the group-policy that you want the ASA to apply > Submit.

00026

Create another profile for your VPN-USERS > Set the correct ACL.

00027

RADIUS > Class-25 > OU set to the group-policy on your ASA for the normal users > Submit.

00028

Cisco ISE Enable Policy Sets

Note: only available on newer versions of ISE: Administration > System > Settings > Policy Sets > Enabled > Submit.

00029

Policy > Policy Sets  > Add.

00030

Continue to PART TWO

Related Articles, References, Credits, or External Links

AnyConnect Group Authentication With Cisco ISE and Downloadable ACLs (Part 2)

Cisco ASA 5500 AnyConnect Setup From Command Line

Author: PeteLong

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