Duplicate RADIUS accounting, same everything except radacctid

[Michael Ducharme]

Hello,

We have a FreeRADIUS 3.0.15 server on CentOS providing authentication 
for PPPoE. Very occasionally we are getting a couple random duplicate 
records in the radacct table. It happens a few times a month. We have 
about 600 customers total, and an interim-update of 30 minutes 
configured on our NAS, so there are many updates that are working and 
only a few strange and occasional exceptions that are not.

Below is an example of one such duplication (with information redacted). 
I checked the accounting text log in /var/log/radius/radacct/nasip and I 
see no duplication in that file for the same record shown below, it only 
appears once (it is an Interim-Update). Any ideas as to what the problem 
might be and how to fix it?

Thanks.


MariaDB [radius]> select * from radacct where acctstoptime is NULL and 
username='Smokefree';+--------

---+---------------+----------------------------------+-----------+-----------+-------+--------------+-----------------+-------------+---------------------+--------------+-----------------+---------------+-------------------+------------------+-----------------+------------------+-----------------+-------------------+--------------------+-------------+----------------+-----------------+----------------+---------------+----------------------+---------------------+--------------+
| radacctid | acctsessionid | acctuniqueid | username  | groupname | 
realm | nasipaddress | nasportid       | nasporttype | 
acctstarttime       | acctstoptime | acctsessiontime | acctauthentic | 
connectinfo_start | connectinfo_stop | acctinputoctets | 
acctoutputoctets | calledstationid | callingstationid  | 
acctterminatecause | servicetype | framedprotocol | framedipaddress | 
acctstartdelay | acctstopdelay | xascendsessionsvrkey | 
acctupdatetime      | acctinterval |
+-----------+---------------+----------------------------------+-----------+-----------+-------+--------------+-----------------+-------------+---------------------+--------------+-----------------+---------------+-------------------+------------------+-----------------+------------------+-----------------+-------------------+--------------------+-------------+----------------+-----------------+----------------+---------------+----------------------+---------------------+--------------+
|    624635 | 8112785d      | d0f315f66688cdadd5b436377f0a51aa | 
Smokefree |           |       | 172.16.160.2 | bridge-pppoe-bc | 
Ethernet    | 2018-08-13 14:49:03 | NULL         |            3600 | 
RADIUS        |                   |                  | 8985136 |        
253567605 | ppp-sonar-bcn   |60:E3:RE:DA:CT:ED |                    | 
Framed-User | PPP            | 206.RED.ACT.ED  |           NULL 
|          NULL | NULL                 | 2018-08-13 15:49:03 |         
1800 |
|    624637 | 8112785d      | d0f315f66688cdadd5b436377f0a51aa | 
Smokefree |           |       | 172.16.160.2 | bridge-pppoe-bc | 
Ethernet    | 2018-08-13 14:49:03 | NULL         |            3600 | 
RADIUS        |                   |                  | 8985136 |        
253567605 | ppp-sonar-bcn   | 60:E3:RE:DA:CT:ED |                    | 
Framed-User | PPP            | 206.RED.ACT.ED  |           NULL 
|          NULL | NULL                 | 2018-08-13 15:49:03 |         
1800 |
+-----------+---------------+----------------------------------+-----------+-----------+-------+--------------+-----------------+-------------+---------------------+--------------+-----------------+---------------+-------------------+------------------+-----------------+------------------+-----------------+-------------------+--------------------+-------------+----------------+-----------------+----------------+---------------+----------------------+---------------------+--------------+