Net 412 (Practical Part) Networks and Communication Department LAB 2

Configuring Point-to-Point GRE VPN Tunnels Generic Routing Encapsulation (GRE) is a tunneling protocol developed by Cisco that allows the encapsulation of a wide variety of network layer protocols inside point-to-point links. A GRE tunnel is used when packets need to be sent from one network to another over the Internet or an insecure network. With GRE, a virtual tunnel is created between the two endpoints (Cisco routers) and packets are sent through the GRE tunnel. It is important to note that packets travelling inside a GRE tunnel are not encrypted as GRE does not encrypt the tunnel but encapsulates it with a GRE header. If data protection is required, IPSec must be configured to provide data confidentiality – this is when a GRE tunnel is transformed into a secure VPN GRE tunnel Networks and Communication Department

Part 1: Configure Networks : Open the packet tracer. Add 2-laptops, 2-switch general-pt,3 3-router 1941. Link all the devices together type of link copper cross . Links between R1 and R3 , R3 and R2 are copper cross ovell Configure Ip address for all Network like topology above Networks and Communication Department

Topology Networks and Communication Department

Configure pc 0 Networks and Communication Department

Configure R1 Networks and Communication Department

Configure R1 Networks and Communication Department

Configure R3 Networks and Communication Department

Configure R3 Networks and Communication Department

Configure R2 Networks and Communication Department

Configure R2 Networks and Communication Department

Configure pc 1 Networks and Communication Department

Show Ip route Networks and Communication Department Router 3 has no idea about networks 192.168.1.0 and 192.168.3.0 Networks and Communication Department

Part 2: Configure GRE Tunnel on Router 1 R1>en R1#config t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#int tunnel 0 R1(config-if)#ip address 192.168.2.1 255.255.255.0 R1(config-if)#tunnel source g0/1 R1(config-if)#tunnel destination 11.1.1.1 R1(config-if)#tunnel mode gre ip R1(config-if)#ex R1(config)#ip route 192.168.3.0 255.255.255.0 192.168.2.2 R2(config)#ip route 0.0.0.0 0.0.0.0 g0/1 R1(config)#do wri Networks and Communication Department

Part 2: Configure GRE Tunnel on Router 1 Networks and Communication Department

Cont. Part 2: Configure GRE Tunnel on Router 1 Networks and Communication Department

Part 3: Configuring GRE Tunnel on Router 2(private Network): R2>en R2#config t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#int tunnel 0 R2(config-if)# %LINK-5-CHANGED: Interface Tunnel0, changed state to up R2(config-if)#ip address 192.168.2.2 255.255.255.0 R2(config-if)#tunnel source g0/1 R2(config-if)#tunnel destination 10.1.1.1 R2(config-if)#tunnel mode gre ip R2(config-if)#ex R2(config)#ip route 192.168.1.0 255.255.255.0 192.168.2.1 R2(config)#ip route 0.0.0.0 0.0.0.0 g0/1 R2(config)#do wri Networks and Communication Department

Part 3: Configuring GRE Tunnel on Router 2(private Network): Networks and Communication Department

Part 4: Tracing the path of networks connected , Use command show ip route R1#show ip route Networks and Communication Department

Part 4 Networks and Communication Department

Part 4 Networks and Communication Department

Part 5: After configuring tunnel, two tunnel endpoints can see each other can verify using an ICMP echo from one end Ping pc-0 from pc-1 Networks and Communication Department

Part 5 Networks and Communication Department

Part 5 Networks and Communication Department

Part 6: use the simulation panel to trace the packet movement. Now both networks (192.168.1.0/24 and 192.168.3.0/24) are able to freely communicate with each other over the GRE Tunnel . Networks and Communication Department

Part 6 Networks and Communication Department

The End Any Questions ? Networks and Communication Department