Draytek Vigor3910 Series User Manual page 51

WAN Connection
Detection
MTU
Vigor3910 Series User's Guide
also can establish the PPPoE connection directly from local
clients to your ISP via the Vigor router. When PPPoA protocol
is selected, the PPPoE package transmitted by PC will be
transformed into PPPoA package and sent to WAN server.
Thus, the PC can access Internet through such direction.
For Wired LAN – If you check this box, PCs on the same
network can use another set of PPPoE session (different with
the Host PC) to access into Internet.
Note: To have PPPoA Pass-through, please choose PPPoA
protocol and check the box(es) here. The router will behave
like a modem which only serves the PPPoE client on the LAN.
That's, the router will offer PPPoA dial-up connection.
Such function allows you to verify whether network
connection is alive or not through ARP Detect or Ping Detect.
Mode – Choose PPP 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/Secondary Ping IP – If you choose Ping Detect as
detection mode, you have to type Primary or Secondary IP
address in this field for pinging.

Ping Gateway IP – If you choose Ping Detect as detection
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 – Type the interval for the system to
execute the PING operation.

Ping Retry – Type 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 – Type the IP address as the specific
transmit path.
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
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