A LAG group on the X1018P managed switch is real easy but switch port configuration is not available on the TZ 500. Is there a way to set it up for 2 ports like x0 and x2 on the firewall and e15 and e16 on the switch? How would I configure the firewall ports? Is this a PortShield Group????
You can't do it on Sonicwall device. TZ series doesn't support link aggregation. Check this doc http://documents.software.dell.com/sonicos/18.104.22.168/release-notes/document-download?ParentProduct=847
the only way is to add a 3rd switch with a trunk connecting the other 2 switches with their trunks and the third switch port 16 to the sonicwall Tz500 and creating the vlans on it