$ORIGIN . $TTL 86400 ; 1 day 13.168.192.in-addr.arpa IN SOA alamo.rlwhome. root.alamo.rlwhome. ( 2006122301 ; serial 10800 ; refresh (3 hours) 3600 ; retry (1 hour) 604800 ; expire (1 week) 3600 ; minimum (1 hour) ) NS alamo.rlwhome. $ORIGIN 13.168.192.in-addr.arpa. 1 PTR alamo.rlwhome. 11 PTR isotope.rlwhome. 13 PTR tritium.rlwhome.