Per title I'm showing connection timed out in the /var/log/cups/error_log.   D [29/Oct/2015:17:43:32 -0400] cupsdSetBusyState: Printing jobsD [29/Oct/2015:17:44:04 -0400] [Job 11441] Connection error: Connection timed outI find that if I change the default OUTPUT policy to ACCEPT, cups processes my print jobs without a hitch. Here is my iptables config (showing policy DROP)Chain OUTPUT (policy DROP 4 packets, 262 bytes) pkts bytes target     prot opt in     out     source               destination         61345   14M ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED    60  3600 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           multiport dports 80,443,636 state NEW,ESTABLISHED     0     0 ACCEPT     icmp --  *      *       0.0.0.0/0            0.0.0.0/0           state NEW,RELATED,ESTABLISHED     1    76 ACCEPT     udp  --  *      *       0.0.0.0/0            0.0.0.0/0           udp dpt:123 state NEW,ESTABLISHED    10   600 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:22 state NEW,ESTABLISHED     4   240 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:25 state NEW,ESTABLISHED   265 15900 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           multiport dports 1433 state NEW,ESTABLISHED    26  1662 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:445 state NEW,ESTABLISHED     0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:631 state NEW,ESTABLISHED     0     0 ACCEPT     udp  --  *      *       0.0.0.0/0            0.0.0.0/0           udp dpt:631 state NEW,ESTABLISHED     0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:139 state NEW,ESTABLISHED  6143 2445K ACCEPT     udp  --  *      *       0.0.0.0/0            0.0.0.0/0           udp dpt:514 state NEW,ESTABLISHED     0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:4443 state NEW,ESTABLISHED I'm allowing outbound traffic on port 631 (upd and tcp).   If I relax OUTPUT to ACCEPT, the print queue processes normally, but I am not showing any outbound traffic on port 631.Here's the relevant section from /etc/cups/cupsd.conf: # Only listen for connections from the local machine.Listen localhost:631Listen /var/run/cups/cups.sockThis configuration worked until yesterday when I moved the printer to a new VLAN (from 2.2.2.2 to 3.3.3.3).  I can ping the printer OK with the firewall up.  What could be going on with my iptables config to prevent print jobs from being sent to the printer? 
cups: connection timed out
centos;iptables;cups;output