(Solution used at HealthSource Athens)
Environment: Sonicwall TZ 350 wireless, W0 (WLAN interface) bridged to X0 (LAN interface)
Issue: WiFi connected Windows and Mac computers experienced intermittent connectivity to wired HP and Brother printers. Printers could be discovered and printed to once after printers were rebooted, but subsequent printing failed.
Solution:
1. Login to the Sonicwall and choose the MANAGE option in the top navigation bar
2. Enable multicast support on the firewall
a. Navigate to Security Configuration / Firewall Settings / Multicast
b. Check the Enable Multicast box in the Multicast Snooping section
c. Choose 'Enable reception of all multicast addresses' in the Multicast Policies section and click ACCEPT
3. Enable multicast support on the X0 and W0 interfaces
a. Navigate to System Setup / Network / Interfaces
b. Click the Configure icon to the right of the X0 interface
c. Click the Advanced tab in the resulting popup window
d. Check the Enable Multicast Support box under Advanced Settings and click OK
e. Repeat steps b-d for the W0 interface
4. Navigate to Policies / Rules / Access Rules
a. Locate the manually created IPv4 MULTICAST rule in the LAN to WAN section
b. If it is set to Deny, click the Configure icon to the right of the rule and change it to Allow
5. Verify that printing works