Draytek Vigor3900 User Manual page 348

5. After filling the required information for Advanced, click the GRE tab to open the
following page.
Available parameters are listed as follows:
Item
Enable GRE
Function
Local GRE IP
Remote GRE IP
Auto Generate
GRE Key
GRE In Key
GRE Out Key
Description
Check the box to enable the function.
The virtual IP address of the router, specified for this tunnel.
The virtual IP address of the remote client, specified for this
tunnel.
Click Enable to generate the GRE key by the system
automatically.
If you click Disable, you need to type GRE key manually.
Type the hexadecimal number as GRE In Key. This value is
used for the router to authenticate the source of the packet.
The length is 4 bytes.
Type the hexadecimal number as GRE Out Key. This value
is used for the remote client to authenticate the source of the
packet. The length is 4 bytes.
340
Vigor3900 Series User's Guide