I have a situation where my hosts file is constantly changing. Because of this I don't want clients to cache ip addresses resolved using the hosts file. Here is the command that starts dnsmasq for me:
/usr/sbin/dnsmasq -K -R -y -Z -b -E -S 188.8.131.52 -l /tmp/dhcp.leases -r /tmp/resolv.conf.auto --stop-dns-rebind --rebind-localhost-ok --dhcp-range=lan,192.168.2.2,192.168.2.249,255.255.255.0,12h -2 eth0
In looking at this site: http://www.thekelleys.org.uk/dnsmasq/docs/dnsmasq-man.html
I see that the -T option has this description:
-T, --local-ttl=<time> When replying with information from /etc/hosts or the DHCP leases file dnsmasq by default sets the time-to-live field to zero, meaning that the requester should not itself cache the information. This is the correct thing to do in almost all situations. This option allows a time-to-live (in seconds) to be given for these replies. This will reduce the load on the server at the expense of clients using stale data under some circumstances.
My command doesn't have the -T option. Do I need it or does dnsmasq default TTL to zero without it?