Draytek VIGOR2925 SERIES User Manual page 194

Detection
MTU
PPP/MP Setup
IP Address Assignment
Method (IPCP)
Vigor2925 Series User's Guide
Detect.
Mode – Choose ARP Detect or Ping Detect for the system
to execute for WAN detection. If you choose Ping Detect as
the detection mode, you have to type required settings for
the following items.

Primary Ping IP – If you choose Ping Detect as
detection mode, you have to type Primary or Secondary
IP address in this field for pinging.

TTL (Time to Live) – Set TTL value of PING
operation.
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 – Type the IP address as the specific
transmit path.

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.
PPP Authentication – Select PAP only or PAP or CHAP
for PPP.
Idle Timeout – Set the timeout for breaking down the
Internet after passing through the time without any action.
Usually ISP dynamically assigns IP address to you each
time you connect to it and request. In some case, your ISP
provides service to always assign you the same IP address
whenever you request. In this case, you can fill in this IP
address in the Fixed IP field. Please contact your ISP before
you want to use this function.
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 32 public IP
addresses other than the current one you are using. Type the
additional WAN IP address and check the Enable box. Then
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