No need to tweak the DB manually! There is a settings for that in “Global Settings” → “Discovery” → “General Discovery Settings”: "Allow Duplicate sysName "
One user nick [TheGreatDoc] wrote this:
" The 10.0.31.2 is the one with Mikrotik sysName.
If you want to allow duplicate sysNames, set this in your config.php: $config['allow_duplicate_sysName'] = true;
But I strongly suggest you to change the sysName in the new (or the already monitored) Mikrotik router to something else, like you have in the others."
So i look the best solution because if you have duplicate sysName maybe librenms wont work like it should
Regards,
dzoki