Aruba Networks, ClearPass, Configuration Example, Security, Switching

Downloadable User-Roles and NTP sync

René Jorissen on February 13, 2019 2 Comments • Tags: #clearpass #switch

The HPE Aruba switches have this cool feature called downloadable user-roles (DUR). DUR enables the switch to use a central ClearPass server to download user-roles to the switch for authenticated users.

More and more customers want to implement wired authentication to strengthen the security level of their network. Via DUR the switches perform an HTTPS API request against ClearPass to download the user-role configuration. This makes the configuration of multiple switches easier, because you don’t need to configure the user-roles locally on the switches anymore, but you push them from a central server. The communication between switch and ClearPass is illustrated in the picture below.

Source: ClearPass Solution Guide: Wired Policy Enforcement

I won’t describe the whole DUR configuration step-by-step, but below you can find the most important configuration for the switch.

radius-server host “” key “radius-secret”
radius-server host “” dyn-authorization
radius-server host “” time-window plus-or-minus-time-window
radius-server host “” time-window 30
radius-server host “” clearpass
radius-server cppm identity “admdur” key “admdur-key”
ip client-tracker trusted
aaa server-group radius “GRP-CPPM” host “”
aaa authentication port-access eap-radius server-group “GRP-CPPM”
aaa authentication mac-based chap-radius server-group “GRP-CPPM”
aaa accounting network start-stop radius server-group “GRP-CPPM”
aaa authentication captive-portal enable
aaa authorization user-role enable download
aaa port-access authenticator 1/1
aaa port-access authenticator 1/1 tx-period 10
aaa port-access authenticator 1/1 supplicant-timeout 10
aaa port-access authenticator 1/1 client-limit 10
aaa port-access mac-based 1/1
aaa port-access mac-based 1/1 addr-limit 10
aaa port-access 1/1 controlled-direction in

For the HTTP GET to work the switch needs to trust the certificate chain from ClearPass. In ArubaOS 16.08 and later the certificate is automatically downloaded when specifying the option “clearpass” when configuring the RADIUS client. Another very important step for DUR to work is NTP time sync. The time on the switches needs to be in sync and here a “problem” arises.

After a switch power outage, the switch has to sync its time with an NTP server. And the time needs to be in sync before the first wired clients start authenticating. Even when I use the “iburst option with the NTP server for aggressive polling, I see that the time isn’t always synced in time.

Below you see the output from “show log -r” when the client authenticates, but the switch hasn’t synced its time yet.

I 02/12/19 10:55:46 04908 ntp: ST1-CMDR: The system clock time was changed by 918813141 sec 661757827 nsec. The new time is Tue Feb 12 10:55:46 2019
I 01/01/90 01:03:11 04911 ntp: ST1-CMDR: The NTP Server is unreachable.
I 01/01/90 01:02:55 00584 WebMacAuth: ST1-CMDR: Port 1/1, re-auth timeout 10 too short.
I 01/01/90 01:02:55 05747 DFP: ST1-CMDR: device_fingerPrinting: Hardware Rules updated successfully for port:1/1, protocol:80, client:08:00:0F:9D:45:BF
W 01/01/90 01:02:55 05204 dca: ST1-CMDR: Failed to apply user role VOIP___DUR-3005-1_7Z4q to macAuth client 08000F9D45BF on port 1/1: user role is invalid.
W 01/01/90 01:02:55 05620 dca: ST1-CMDR: macAuth client 08000F9D45BF on port 1/1 assigned to initial role as downloading failed for user role VOIP___DUR-3005-1.
I 01/01/90 01:02:51 00076 ports: ST1-CMDR: port 1/1 is now on-line
I 01/01/90 01:02:51 00435 ports: ST1-CMDR: port 1/1 is Blocked by STP

The port is placed in the initial-role which is by default the role denyall. “Problem” with the default role is the missing option “reauthentication period”, so the connected clients will not automatically reauthenticate after an X-period of time.

User Role Information
Name : denyall
Type : predefined
Reauthentication Period (seconds) : 0
Cached Reauth Period (seconds) : 0
Logoff Period (seconds) : 300

To “fix” this issue I added a new local user-role to the switch and configured this user-role as initial-role. I added the reauthentication period to the user-role, so the clients reauthenticate when time isn’t synced yet and they receive this initial-role from the switch. The configuration of the role is displayed below.

class ipv4 “IP_ANY_ANY”
10 match ip
policy user “DENYALL”
10 class ipv4 “IP_ANY_ANY” action deny
aaa authorization user-role name “reauth-role”
policy “DENYALL”
reauth-period 30
vlan-id 1

To use this role as initial-role you need to execute the following command.

aaa authorization user-role initial-role reauth-role

Next I tested the role by rebooting the switch. After rebooting I noticed that the switch port is placed in the “reauth-role“, because I receive the error message “assigned to initial role as downloading failed for user role” in the logs. In ClearPass I see another authentication request from the client after X seconds. At that moment the time on the switch is in sync and the switch port is configured with the correct user-role.

Edited: February 13th 2019
I created a topic on the AirHeads community on this matter and HPE Aruba responded with:

A software fix for the clock reset on cold boot/power loss issue on the 2930F and 2540 is in the works, and is expected to be released by the end of February.

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René Jorissen

Co-owner and Solution Specialist at 4IP Solutions
René Jorissen works as Solution Specialist for 4IP in the Netherlands. Network Infrastructures are the primary focus. René works with equipment of multiple vendors, like Cisco, Aruba Networks, FortiNet, HP Networking, Juniper Networks, RSA SecurID, AeroHive, Microsoft and many more. René is Aruba Certified Edge Expert (ACEX #26), Aruba Certified Mobility Expert (ACMX #438), Aruba Certified ClearPass Expert (ACCX #725), Aruba Certified Design Expert (ACDX #760), CCNP R&S, FCNSP and Certified Ethical Hacker (CEF) certified. You can follow René on Twitter and LinkedIn.

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  1. Kay Kawatra says:

    Hi Rene,

    Thank you for your post. I was able to configure a 3810 switch to download user role from the Clearpass. I’m trying to do the same thing with S3500 but getting the following errors

    Aug 17 08:39:30 :199802: |authmgr| Old Role: Printer-3045-12 found but wrong version:12 to current:12
    Aug 17 08:39:30 :124004: |authmgr| Role:Printer-3045-12 does not have older version
    Aug 17 08:39:30 :124004: |authmgr| Enqueued MAC:40:b0:34:a2:17:36 to role:Printer-3045-12, total:1
    Aug 17 08:39:30 :124004: |authmgr| Checking reference count for role:Printer-3045-12
    Aug 17 08:39:30 :199802: |authmgr| Role:Printer-3045-12 processing stopped due to whitelist violation
    Aug 17 08:39:30 :124004: |authmgr| Role:Printer-3045-12 is now locked from modifications
    Aug 17 08:39:30 :199802: |authmgr| remains in previous role. Downloaded Role: Printer-3045-12 is in unrecoverable failure state.
    Aug 17 08:39:30 :124004: |authmgr| Checking reference count for role:Printer-3045-12

    Would you be able to help me with this?

  2. Alex Sharaz says:

    Hi, many thnaks for the article.

    I have a similar config except i want my initialrole to be an alllow all. he clearpass service that is used runs in monitor mode so never pases back a DUR, the theory being that we can look at device fingerprinting and check that a DUR would place it into the correct vlan.

    I am constantly getting user role invalid messages for my individual ports. What I have is

    class ipv4 “DNS”
    10 match udp eq 53
    20 match udp eq 53
    30 match udp eq 53
    class ipv4 “all”
    10 match ip
    class ipv4 “DHCP”
    10 match udp eq 67
    class ipv4 “ICMP”
    10 match icmp
    class ipv4 “Permit-All”
    10 match ip
    policy user “AllowAll”
    10 class ipv4 “DHCP” action permit
    20 class ipv4 “DNS” action permit
    30 class ipv4 “ICMP” action permit
    40 class ipv4 “Permit-All” action permit
    aaa authorization user-role name “initial-role”
    policy “AllowAll”
    aaa authorization user-role name “mydevices”
    policy “AllowAll”
    vlan-name “mydevices”
    aaa authorization user-role enable download
    aaa authorization user-role initial-role “initial-role”

    aaa port-access 2 controlled-direction in
    aaa port-access 2 auth-order authenticator mac-based
    aaa port-access 2 auth-priority authenticator mac-based
    aaa port-access 2 critical-auth user-role “mydevices”
    aaa port-access 2 initial-role “initial-role”

    I seem to have 3 problems,

    1). a reboot clears the policy statement
    2). constantly get

    W 07/16/23 07:03:33 05204 dca: Failed to apply user role to macAuth client
    D452EE0717F2 on port x: user role is invalid.

    messages ( although possibly removing the initial role statement from the port config may have cured this)
    3). There seems to be an interaction between. defice fingerprinting on the switch and. having a reauth statement in the role definition. If you have a reauth statement fingerprinting doesnt work, remove the reauth and it does

    This is on a 2930 WC.16.11.12


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