Ubuntu server 14.04, bind9, isc-dhcp-server, dDNSI have been messing around on my lab machine at home and have dhcp and dns working finally. One thing that is strange that I cannot figure out - even though I have my default TTL set to a week, some of my devices (most, but not all, are dynamic updated from dhcp to dns zones). Anyone have an ideas why this might be?dhcpd.conf:# The ddns-updates-style parameter controls whether or not the server will# attempt to do a DNS update when a lease is confirmed. We default to the# behavior of the version 2 packages ('none', since DHCP v2 didn't# have support for DDNS.)ddns-updates on;ddns-update-style interim;update-static-leases on;# option definitions common to all supported networks...option domain-name linux.mxxxx;option domain-name-servers 192.168.10.22;# This option points to the same rndc.key created for bind9include /etc/bind/rndc.key;allow unknown-clients;use-host-decl-names on;default-lease-time 604800; max-lease-time 604800;# If this DHCP server is the official DHCP server for the local# network, the authoritative directive should be uncommented.authoritative;# Use this to send dhcp log messages to a different log file (you also# have to hack syslog.conf to complete the redirection).log-facility local7;# linux.mxxxx DNS Zoneszone linux.mxxxx. {    primary 192.168.10.22;  # This server is the primary DNS server for the zone    key rndc-key;           # Use the key defined for dynamic updates}zone 10.168.192.in-addr.arpa. {    primary 192.168.10.22;  # This server is the primary reverse DNS for the zone    key rndc-key;           # Use the key defined for dynamic updates}# linux.mxxxx LAN rangesubnet 192.168.10.0 netmask 255.255.255.0 {    range 192.168.10.100 192.168.10.140;    option subnet-mask 255.255.255.0;    option routers 192.168.10.1;    option domain-name-servers 192.168.10.22;    option domain-name linux.mxxxx;    ddns-domainname linux.mxxxx;    ddns-rev-domainname 10.168.192.in-addr.arpa.;}dns forward zone file:$ORIGIN .$TTL 604800     ; 1 weeklinux.mxxxx            IN SOA  ubuntu-gateway.linux.mxxxx. mxxx.ubuntu-    gateway.linux.mxxxx. (                            17         ; serial                            604800     ; refresh (1 week)                            86400      ; retry (1 day)                            2419200    ; expire (4 weeks)                            604800     ; minimum (1 week)                            )                    NS      ubuntu-gateway.linux.mxxxx.$ORIGIN linux.mxxxx.$TTL 3600       ; 1 houramazon-15d0d453d        A       192.168.10.107                    TXT     00c84394ddff0520bcfeb7c1679a76830famazon-541c86b29        A       192.168.10.100                    TXT     00b3cd2a72b877f4932c6c8160a9a0b12bandroid-1beb470e98f8fa24 A      192.168.10.108                    TXT     000f3b56c299c0d84259f33ab9fa88a19bandroid-81eff891f77c0b58 A      192.168.10.110                    TXT     317970d608a22cbacce86151ff1b26e1f8android-8375a979124d58f5 A      192.168.10.111                    TXT     31ea1ca48854ae0f4b66b8f54342e1ea06Chromecast              A       192.168.10.120                    TXT     00a009b2082bea31079b90c303d598b853kindle-504d6b9ed        A       192.168.10.104                    TXT     00267d6df036927afade592214f82067c9mxxx-LENOVO             A       192.168.10.119                    TXT     31758e8be41b2943d8dab5f5852565fd10mxxxx-HOME-PC          A       192.168.10.113                    TXT     31d13f3ffad33145b54be4cbed30d9809c$TTL 604800     ; 1 weekmxxxx-nas              A       192.168.10.57 ; staticmodem                   A       192.168.10.1 ; static$TTL 3600       ; 1 hourNP-J0A0DR001317         A       192.168.10.105                    TXT     00750fecaf759d8fecc9960d0ac5c31b7e$TTL 604800     ; 1 weekrpi-lan                 A       192.168.10.98 ; staticrpi-wireless            A       192.168.10.97 ; staticubuntu-gateway          A       192.168.10.22 ; staticrDNS Zone (all dynamic with 3600 TTL ):$ORIGIN .$TTL 604800     ; 1 week10.168.192.in-addr.arpa IN SOA  ubuntu-gateway.linux.mxxxx. mxxx.ubuntu-   gateway.linux.mxxxx. (                            15         ; serial                            604800     ; refresh (1 week)                            86400      ; retry (1 day)                            2419200    ; expire (4 weeks)                            604800     ; minimum (1 week)                            )                    NS      ubuntu-gateway.linux.mxxxx.$ORIGIN 10.168.192.in-addr.arpa.1                       PTR     modem.linux.mxxxx.$TTL 3600       ; 1 hour100                     PTR     amazon-541c86b29.linux.mxxxx.104                     PTR     kindle-504d6b9ed.linux.mxxxx.105                     PTR     NP-J0A0DR001317.linux.mxxxx.107                     PTR     amazon-15d0d453d.linux.mxxxx.108                     PTR     android-1beb470e98f8fa24.linux.mxxxx.110                     PTR     android-81eff891f77c0b58.linux.mxxxx.111                     PTR     android-8375a979124d58f5.linux.mxxxx.113                     PTR     mxxxx-HOME-PC.linux.mxxxx.115                     PTR     XboxOne.linux.mxxxx.119                     PTR     mxxx-LENOVO.linux.mxxxx.120                     PTR     Chromecast.linux.mxxxx.119.10.168.192          PTR     mxxx-LENOVO.linux.mxxxx.$TTL 604800     ; 1 week97                      PTR     rpi-wireless.linux.mxxxx.98                      PTR     rpi-lan.linux.mxxxx.
Bind9 & DHCP, Why are some of my records getting a very short TTL?
ubuntu;dhcp;bind9