Here is some more information:
First, I'll post some keywords for search engines to find. AVG Firewall Wireless Printer HP J4680 J4600 Dell Lexmark
1. Bring up AVG.
2. Click on History at the top, then firewall below that.
3. You should see your firewall logs sorted so that the latest date is at the bottom. You'll probably see UDP port 427 being blocked.
4. If you have the right one being blocked it will be associated with SVCHOST.EXE.
5. Right Click on that line and choose "Edit Rule in .......".
6. That will bring up the ruleset that controls what is allowed by SVCHOST.EXE.
7. Click Add.
8. Under Protocol, click on TCP. In the Change Protocol window, click on UDP.
9. Under Direction, click Out. In the next window, click Both Ways.
10. Under Local Ports, click Undefined. In the next window, click ALL Ports.
11. Under Remote Ports, click undefined. In the next window, click user selected ports and add "161, 427" to the blank list.
12. Under Remote addresses, click undefined. In the next window, choose Safe Networks (that should include Local Networks below it) and then hit Add IP. In that window, leave the setting of One IP with 0.0.0.0. -- this is a quirk of svchost.ext. click OK to work your way out to the Change Rule Detail.
13. Click Allow for all and change to Allow for Safe.
14. Check the Log this rule detail activity.
15. Change the Rule Detail Name to something like "Wireless Printer Ports".
16. Click OK.
17. Now you should see your rule at the bottom of the rule list and the one above it called Terminate.
18. Click on your rule and then click Move Up to place it above Terminate or it won't work because the firewall does these rules in order and if it hits terminate before it gets to your rule, it stops there and prevents other rules from firing.
19. Click Apply and then go look at the rules. The printer should be working now.
20. If you see an IGMP message that is your router doing some work. You add IGMP messages in System Service and then click Manage User System Rules.
a. Protocol IGMP, Direction Both Ways, local ports is set to all ports, remote ports is set to all ports.
b. remote addresses are safe network, local networks and 126.96.36.199/4 (added by clicking add IP and in IP address/mask put an address of 188.8.131.52 and a mask of 240.0.0.0)
c. Allow for safe
d. Log rule activity
e. Click OK
f. Click Apply.