ISE Lab: Wired 3 – 802.1x Posture

The posture configuration is very similar to the one that was created in the Anyconnect VPN post. This post will go over the posture steps and demonstrate what it looks like on a switch and also in the ISE RADIUS live logs.

On a wired LAN connection using dot1x the ISE posture can determine based off a username if the device is a corporate machine and place them into a corporate VLAN. If the client is unknown, move it to a guest VLAN with a specific ACL, or deny them altogether.

For this lab demonstration, posture results will have the following outcomes;

  • Have a default guest VLAN on the switchport
  • Guest VLAN will have an ACL that denies traffic to the LAN, except for posture and DHCP/DNS
  • If a user is compliant, they will be placed into an employee VLAN
    • Users will have an ACL based off their groups

Employee Compliance Posture Fail

The employee will connect to the network and have a scan run. This example will show what happens when that employee computer fails the posture.

Unknown Compliance Status

The client is first unknown, they will receive a posture redirect ACL and wired guest ACL. The switchport is configured with the VLAN 70 in network 172.17.70.0/24. The client has a 4 minute grace period to fix their posture status before they are moved to non-compliant posture status.

1 Posture Redirect profile

Switch posture redirect ACL referenced by above authorisation profile

1 Wired Guest profile
1 Wired non-compliant ACL

On the computer, switch and ISE the current unknown or posture remediation looks like…

Non-compliant Compliance Status

If the client does not remediate their posture status, so it is successful in the 4 minute time, then they will be placed into VLAN 4 as they are an employee and be give the same access as a guest. So essentially, nothing changes for them access wise. Only the VLAN does.

2 Posture Redirect profile

Switch posture redirect ACL referenced by above authorisation profile

2 wired employee non compliant profile
2 Wired non compliant ACL

On the computer, switch and ISE the current unknown or posture remediation looks like…
Note how the IP address has changed from 172.17.70.x to 172.17.4.x. This is the result of ISE changing the VLAN. The client has requested a new IP from the DHCP server, which is permitted by the ACLs that it is given.

Employee Compliance Posture Success

This process will begin with the same unknown posture status, and then move to compliant very quickly.
The first half will be exactly the same as the unknown posture status above.
The client will start off in VLAN 70, moving to VLAN 4. There will be two DHCP requests that will be seen in a capture.

2 wired employee
2 Wired employee compliant ACL

Now to test the client and see that it becomes compliant

DHCP 1 for VLAN 70
DHCP 2 for VLAN 4
Entire process captured by ISE
Final result

Guest Compliance Fail

This type of user is expected to fail. The only difference between the guest user and the employees are that the guest user will remain in VLAN 70.
The guests will stay on the first step, never moving to non-compliant status.

Leave a Comment

Your email address will not be published. Required fields are marked *