IpConfig/TTL Registry Key
The IpConfig/TTL Registry key defines the lifespan of a network packet. The
time-to-live value is a kind of upper bound on the time that an IP datagram
can exist in the Internet system. The value is reduced with the passage
through a router (a hop). If it reaches 0 the packet is discarded.
The TTL setting can be considered to limit the maximum radius (in terms of
hops) of the network within reach of the JNIOR. The default setting should
allow packets to reach the far end of the globe. A low setting would limit
access to the unit as only those in the local vicinity could communicate with
it. In this respect the TTL setting can be used to improve device security.
A very low setting of 1 or 2 would constrain the JNIOR to the immediate
network. One must consider the need to reach Doman Name Servers (DNS) and
Network Time Servers (NTP). There may also be the requirement for email
transfers wherein the JNIOR needs to reach out to a SMTP Server. To help
determine the minimum setting you may be able to use your PC's TRACERT
command to detect the hop count involved in reaching those destinations.
The JNIOR does not support a route tracing function.