User`s guide

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This option is normally used in conjunction with IPSec. This parameter should not be
used if the interface is selected as the source using the “Use Interface” options above.
Destination IP Address or Hostname:
This is the FQDN or IP address of the remote end of the tunnel. This could also be the
virtual host IP address for the remote end of the tunnel, configured for routing purposes.
e.g. 2.2.2.2
Enable keepalives on this GRE tunnel
Selecting this checkbox will display the GRE keepalive parameters. Keepalives are needed
so allow the router to determine whether the tunnel interface is receiving traffic correctly or
not. If keepalives fail, the tunnel will be marked as down.
Send a keepalive every s seconds
When configured to a non-zero value, keepalive packets will be sent to the remote end of
the tunnel and the response is monitored to detect if the tunnel is up or down. If the tunnel
is detected as down, the routing table metric will be altered. Value is configured in seconds.
If this value is set to zero then keepalives will not be used.
Bring this GRE tunnel down after no replies to n keepalives
This parameter specifies the consecutive number of keepalive packets that need to fail
before the tunnel is detected as being down.
Bring this GRE interface up to send keepalives
This specifies whether or not the GRE keepalive packets will activate the tunnel. If set to
YES and the tunnel drops the GRE keepalive packet will try to raise the tunnel again. If set
to NO and the tunnel has been marked as down due to the GRE keepalives not being
received, the router will only raise the tunnel if a packet (other than a GRE keepalive) needs
to be routed.
Related CLI Commands
Entity
Instance
Parameter
Values
Equivalent Web Parameter
tun n descr Free text field Description
tun n IPaddr Valid IP address IP Address
tun n mask Valid Subnet Mask Mask
tun n source_ent blank,ETH,PPP
Use interface x,y for the source
IP address of GRE packets
x = Interface type
tun n source_add 0 - 255
Use interface x,y for the source
IP address of GRE packets
y = interface number
tun n source Valid IP address
Source IP address to use for GRE
packets
tun n dest Valid IP address
Destination IP address to use for
GRE packets
tun n Kadelay Seconds Send a keepalive every s seconds
tun n karetries Number
Bring this GRE tunnel down after
no replies to n keepalives