Draytek Vigor2620 LTE Series User Manual page 90

MTU
RIP Protocol
TTL
WAN IP Network Settings
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mode, you also can enable this setting to use current WAN
gateway IP address for pinging.
With the IP address(es) pinging, Vigor router can check if
the WAN connection is on or off.

TTL (Time to Live) – Set TTL value of PING operation.

Ping Interval – Enter the interval for the system to
execute the PING operation.

Ping Retry – Enter the number of times that the system is
allowed to execute the PING operation before WAN
disconnection is judged.
It means Max Transmit Unit for packet.
Path MTU Discovery – It is used to detect the maximum MTU
size of a packet not to be segmented in specific transmit
path.
Click Detect to open the following dialog.
Path MTU to – Choose the destination as the specific

transmit path and Enter the IP address.
 MTU size start from - Determine the starting point
value of the packet.
MTU reduce size by – It determines the decreasing size

of MTU value. For example, the number specified in
this field is "8". The maximum MTU size is "1500".
After clicking the "detect" button, the system will
calculate and get the suitable MTU value such as 1500,
1492, 1484 and etc., automatically.
Detect – Click it to detect a suitable MTU value

Accept – After clicking it, the detected value will be

displayed in the field of MTU.
Routing Information Protocol is abbreviated as RIP （RFC1058）
specifying how routers exchange routing tables information.
Click Enable RIP for activating this function.
Change the TTL value – Enable or disable the TTL (Time to
Live) for a packet transmitted through Vigor router.
Enable - TTL value will be reduced (-1) when it passess
through Vigor router. It will cause the client, accessing
Internet through Vigor router, be blocked by certain ISP
when TTL value becomes "0".
Disable – TTL value will not be reduced. Then, when a packet
passes through Vigor router, it will not be cancelled. That is,
the client who sends out the packet will not be blocked by
ISP.
This group allows you to obtain an IP address automatically
and allows you Enter IP address manually.
WAN IP Alias - If you have multiple public IP addresses and
would like to utilize them on the WAN interface, please use
WAN IP Alias. You can set up to 8 public IP addresses other
Vigor2620 Series User's Guide