Geneko GWR-I series, User Manual

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USER MANUAL GWR-I Cellular Router Series
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GRE Tunnel configuration between GWR-I Router and third party router
GRE tunnel is a type of a VPN tunnels, but it isn't a secure tunneling method. However, you can
encrypt GRE packets with an encryption protocol such as IPSec to form a secure VPN.
On the diagram below ( Figure 59 ) is illustrated simple network with two sites. Idea is to create GRE
tunnel for LAN to LAN (site to site) connectivity.
Figure 59 - GRE tunnel between Cisco router and GWR-I Router
GRE tunnel is created between Cisco router with GRE functionality on the HQ Site and the GWR-I
Router on the Remote Network. In this example, it is necessary for both routers to create tunnel interface
(virtual interface). This new tunnel interface is its own network. To each of the routers, it appears that it has
two paths to the remote physical interface and the tunnel interface (running through the tunnel). This tunnel
could then transmit unroutable traffic such as NetBIOS or AppleTalk.
The GWR-I Router uses Network Address Translation (NAT) where only the mobile IP address is
visible to the outside. All outgoing traffic uses the GWR-I Router WAN/VPN mobile IP address. HQ Cisco
router acts like gateway to remote network for user in corporate LAN. It also performs function of GRE
server for termination of GRE tunnel. The GWR-I Router act like default gateway for Remote Network and
GRE server for tunnel.
1. HQ router requirements:
•
HQ router require static IP WAN address;
•
Router or VPN appliance have to support GRE protocol;
•
Tunnel peer address will be the GWR-I Router WAN's mobile IP address. For this reason, a static
mobile IP address is preferred on the GWR-I Router WAN (GPRS) side;
•
Remote Subnet is remote LAN network address and Remote Subnet Mask is subnet of remote
LAN.
2. The GWR-I Router requirements: