Draytek VIGOR2925 SERIES User Manual page 218

IPv4 Border Relay
IPv4 Mask Length
6rd Prefix
6rd Prefix Length
WAN Connection
Detection
After finished the above settings, click OK to save the settings.
Below shows an example for successful IPv6 connection based on 6rd mode.
Vigor2925 Series User's Guide
Type the IPv4 addresses of the 6rd Border Relay for a given
6rd domain.
Type a number of high-order bits that are identical across
all CE IPv4 addresses within a given 6rd domain.
It may be any value between 0 and 32.
Type the 6rd IPv6 address.
Type the IPv6 prefix length for the 6rd IPv6 prefix in
number of bits.
Such function allows you to verify whether network
connection is alive or not through Ping Detect.
Mode – Choose Always On or Ping Detect for the system
to execute for WAN detection. Always On means no
detection will be executed. The network connection will be
on always.

Ping IP/Hostname – If you choose Ping Detect as
detection mode, you have to type IP address in this field
for pinging.

TTL (Time to Live) –If you choose Ping Detect as
detection mode, you have to type TTL value.
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