Description

Customer is configuring 802.1x authentication on a Juniper switch with a dynamic ACL defined in Cisco ISE. The dynamic ACL is defined with multiple Juniper-Switching-Filter--[48] VSA Match Conditions

 Access Type = ACCESS_ACCEPT

Juniper-Switching-Filter = match source-port 68 destination-port 67 action allow
Juniper-Switching-Filter = match destination-port 53 action allow
Juniper-Switching-Filter = match destination-ip 10.140.5.100/32 action allow
Juniper-Switching-Filter = match destination-ip 10.219.248.112/32 action allow
Juniper-Switching-Filter = match destination-ip 10.219.248.111/32 action allow
Juniper-Switching-Filter = match destination-ip 10.192.100.100/32 action allow
Juniper-Switching-Filter = match destination-ip 10.104.1.175/32 action allow
Juniper-Switching-Filter = match destination-ip 10.85.254.68/32 action allow
Juniper-Switching-Filter = match destination-ip 10.142.100.161/32 action allow
Juniper-Switching-Filter = match destination-ip 10.104.5.20/32 action allow
Juniper-Switching-Filter = match destination-ip 10.104.5.42/32 action allow
Juniper-Switching-Filter = match destination-ip 10.85.254.4/32 action allow
Juniper-Switching-Filter = match destination-ip 10.85.254.20/32 action allow
Juniper-Switching-Filter = match destination-ip 10.85.254.52/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.219.133/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.219.212/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.219.134/32 action allow
Juniper-Switching-Filter = match destination-ip 10.164.255.215/32 action allow
Juniper-Switching-Filter = match destination-ip 10.223.10.63/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.4.142/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.223.72/32 action allow
Juniper-Switching-Filter = match destination-ip 10.6.40.233/32 action allow
Juniper-Switching-Filter = match destination-ip 10.6.40.234/32 action allow
Juniper-Switching-Filter = match destination-ip 10.6.40.133/32 action allow
Juniper-Switching-Filter = match destination-ip 10.214.49.137/32 action allow
Juniper-Switching-Filter = match destination-ip 10.214.50.238/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.221.151/32 action allow
Juniper-Switching-Filter = match destination-ip 10.2.10.139/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.221.20/32 action allow
Juniper-Switching-Filter = match destination-ip 10.61.212.110/32 action allow
Juniper-Switching-Filter = match destination-ip 10.61.212.111/32 action allow
Juniper-Switching-Filter = match destination-ip 10.61.212.50/32 action allow
Juniper-Switching-Filter = match destination-ip 10.61.212.59/32 action allow
Juniper-Switching-Filter = match destination-ip 10.40.246.10/32 action allow
Juniper-Switching-Filter = match destination-ip 10.61.212.20/32 action allow
Juniper-Switching-Filter = match destination-ip 10.61.214.200/32 action allow
Juniper-Switching-Filter = match destination-ip 10.61.214.205/32 action allow
Juniper-Switching-Filter = match destination-ip 172.29.224.140/32 action allow
Juniper-Switching-Filter = match destination-ip 172.29.206.60/32 action allow
Juniper-Switching-Filter = match destination-ip 172.29.206.9/32 action allow
Juniper-Switching-Filter = match destination-ip 192.168.40.229/32 action allow
Juniper-Switching-Filter = match destination-ip 172.16.76.191/32 action allow

 

Customer gets an error in the dynamic Dot1x filter "Held state Reason: Error tokenizing switching-filter"

 

Customer has the dACL working as expected with one match condition per VSA line as follows:

 

Below are the attributes for the full dACL: if only 20lines the filter is installed correctly

Symptoms

Looking at the documentation:
https://www.juniper.net/documentation/us/en/software/junos/user-access/topics/topic-map/user-access-radius-authentication.html#id-juniper-networks-vendor-specific-radius-attributes
"The 4000 character limit is subject to supported MTU on both the RADIUS server and the Juniper device, and the number of other RADIUS attributes used" But the customer seems to be below this limit.

mist@switch > show dot1x interface ge-0/0/0 detail
ge-0/0/0.0
Role: Authenticator
Administrative state: Auto
Supplicant mode: Multiple
Number of retries: 3
Quiet period: 2 seconds
Transmit period: 2 seconds
Mac Radius: Enabled
Mac Radius Restrict: Disabled
Mac Radius Authentication Protocol: EAP-MD5
Reauthentication: Enabled
Reauthentication interval: 3600 seconds
Supplicant timeout: 10 seconds
Server timeout: 30 seconds
Maximum EAPOL requests: 3
Guest VLAN : not configured
Last Mac-Learn Request: xx:xx:xx:xx:xx:xx
Last Mac-Learn Time: 2025-12-10 10:33:06.815085
Number of connected supplicants: 1
Supplicant: xxxxxxxxxxxx, x:x:x:x:x:x
Operational state: Held
Held state Reason: Error tokenizing switching-filter     <<<<<<<<<< error
Backend Authentication state: Idle
Authentication method: Mac Radius
Session Reauth interval: 0 seconds
Reauthentication due in 0 seconds
Session Accounting Interim Interval: 600 seconds
Accounting Update due in 0 seconds
Eapol-Block: Not In Effect
Domain: Data

Solution

You can use multiple instances of the Juniper-switching-filter attribute with a maximum limit of 20 match conditions and a maximum total size of 4000 characters, The maximum length of any radius attribute is 253 characters, so each line of the "Juniper-switching-filter" attribute should also be less than 253 characters.

Also, attributes can be reconfigured, reconfigure the attributes using shorter characters descriptors:

 destination-mac / dst-mac

 destination-port / dst-port

 destination-ip / dst

source-ip / src

 ip-protocol / ip-proto

 source-port / src-port

...

 

"For longer switching-filters, use multiple instances of the Juniper-switching-filter attribute with a maximum limit of 20 match conditions and a maximum total size of 4000 characters. The maximum length of any radius attribute is 253 characters, so each line of the "Juniper-switching-filter" attribute should also be less than 253 characters."

 

Check for more details here:

https://www.juniper.net/documentation/us/en/software/junos/user-access/topics/topic-map/802-1x-authentication-switching-devices.html

Modification History

2026-02-18 : Article Created