Auto-Discovery fails, no IP from CDP

Hi Guys

i need you help with the auto-discovery function

our new distributed librenms deployment looks like this
1 web node - pol and discovery disabled - default poller group
1 poller node - only node for pol and discovery - poller group 2
1 database server
1 redis,rrd,memcache server.

we are experiencing issues with the auto-discovery part
discover by ip enabled - global and on the poller node.
XDP enabled - global and on the poller node.

when we ran the discovery.php the first time the server found 79 devices and added them to the database.
we found that we where missing quite a few devices and should have been added as well, but for some reason was not added.

when i ran the discovery job again with some debug info i can see that the job is trying to discover the devices but it looks like it is not identifying the IP address and therefore fails the discovery process.

the devices do not have a DNS record, hence the discover by IP.
i cant for the life of me figure out why the IP address is not discovered. we have devices of similar model, and config that is beeing discovered fine.

the main part i am noticing is from the discovery log is

  • discovering

  • name lookup of failed

  • SQL[[1;33minsert into eventlog (reference, type, datetime, severity, message, username, device_id) values (?, ?, ?, ?, ?, ?, ?) [0;33m[null,“discovery”,“2023-03-22 11:58:50”,5,“CDP discovery of failed - Check name lookup”,“”,6][0m 2ms]

  • discovering

  • Discovery failed: ‘’ is not a valid ip or dns name

validate php output

[[email protected] ~]$ ./validate.php

Component Version
LibreNMS 23.2.0-30-g0e322ae5d (2023-03-13T16:19:23+01:00)
DB Schema 2022_09_03_091314_update_ports_adsl_table_with_defaults (248)
PHP 8.1.16
Python 3.6.8
Database MariaDB 10.3.35-MariaDB
RRDTool 1.7.0
SNMP 5.8

[OK] Composer Version: 2.5.4
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database Schema is current
[OK] SQL Server meets minimum requirements
[OK] lower_case_table_names is enabled
[OK] MySQL engine is optimal
[OK] Database and column collations are correct
[OK] Database schema correct
[OK] MySQl and PHP time match
[OK] Distributed Polling setting is enabled globally
[OK] Connected to rrdcached
[OK] Active pollers found
[OK] Dispatcher Service is enabled
[OK] Locks are functional
[OK] Python wrapper cron entry is not present
[OK] Redis is functional
[OK] rrdtool version ok
[OK] Connected to rrdcached