User guide

VPN Configuration
Rev 2.0 C Aug.10 61
GRE
The AirLink Device can act as a Generic Routing Encapsulation (GRE) endpoint,
providing a means to encapsulate a wide variety of network layer packets inside
IP tunneling packets. With this featureyou can reconfigure IP architectures without
worrying about connectivity. GRE creates a point-to-point link between routers on
an IP network.
Figure 6-3: ACEmanager: VPN - VPN1- GRE Tunnel
Log
The VPN log can be used for troubleshooting purposes when setting up the IPsec
and/or GRE configuration. The Log page will allow you to establish the tunnel
connection and monitor the results directly. To change the intervals at which the
log is displayed, you can change the settings in Auto Refresh.
Following are few main action tabs on the log page:
• Connect - indicates connecting to the tunnel.
• Refresh - is the option to refresh the page manually.
• Clear - clicking on Clear will clear out the tunnels.
• Apply Policy - will establish tunnel specification.
NAT-T Keep Alive
Interval
Length of time between NAT-T keep alive packets. The default is set to 20 seconds.
Users who have devices behind the carrier firewall, and who need to use IPSec, NAT-T
feature is useful in such scenarios. As the carrier is performing NAT on the IP traffic, the
key exchange required for IPSec cannot be performed, preventing operation of IPSec
behind the firewall. With the addition of the NAT-T (NAT Traversal) protocol, IPSec tunnels
can be established between devices across the firewall.
NAT-T End Timer If the tunnel is idle for one whole SA-Life time then the tunnel will not rekey itself. After this
period, the carrier waits for that givem time and then takes away the port and IP associated
with this device.
Command Description