lldpd (and probably ladvd) doesn't work on units with an integrated switch
It appears the GUI configuration doesn't probably figure out what interface is selected. For example,
No matter what I do in the GUI, lldpd's startup file has this...
/usr/local/sbin/lldpd -l -I 'ix2,ix3' -C 'ix2,ix3' -m '172.22.18.2'
...and lldp doesn't work.
After I manually changed it to:
/usr/local/sbin/lldpd -l -I 'lagg0.4089' -C 'lagg0.4089' -m '172.22.18.2'
This was thoroughly tested on an XG7100 but I'm pretty sure the same issue applies to SG3100s