Draytek Vigor2912 Series User Manual page 109

Available settings are explained as follows:
Item
Enable / Disable
Keep WAN Connection
WAN Connection
Detection
MTU
Description
Click Enable for activating this function. If you click
Disable, this function will be closed and all the settings that
you adjusted in this page will be invalid.
Normally, this function is designed for Dynamic IP
environments because some ISPs will drop connections if
there is no traffic within certain periods of time. Check
Enable PING to keep alive box to activate this function.
PING to the IP - If you enable the PING function, please
specify the IP address for the system to PING it for keeping
alive.
PING Interval - Enter the interval for the system to
execute the PING operation.
Such function allows you to verify whether network
connection is alive or not through ARP Detect or Ping
Detect.
Mode – Choose ARP Detect or Ping Detect for the system
to execute for WAN detection.
Ping IP – If you choose Ping Detect as detection mode, you
have to type IP address in this field for pinging.
TTL (Time to Live) – Displays value for your reference.
TTL value is set by telnet command.
It means Max Transmit Unit for packet. The default setting
99 Vigor2912 Series User's Guide