GRE Protocol Overview
637
GRE Services
GRE can fulfill the following services:
1
Implement the LAN protocol communication in WAN by encapsulating all kinds of
LAN protocols into a WAN protocol.
Figure 201
Multi-protocol local network transmitting via single-protocol backbone
network
In Figure 201, Group1 and Group2 are the local networks running the Novell IPX
protocol. Term1 and Term2 is the local network running the IP protocol. The tunnel
encapsulated by the GRE protocol is created between Router A and Router B. Thus
Group1 and Group2 can communicate without affecting each other, as can Term1
and Term2.
2
Enlarge the operating range of the hop-limited network, such as IPX.
Figure 202
Enlarge network operating range
When using RIP, if the hop count between two terminals in Figure 202 is more
than 15, the two terminals cannot communicate with each other. If tunneling is
used in the network, hop counts will not be incremented inside the tunnel, that is,
hops can be hidden, which enlarges the operating range of the network.
3
Connect some discontinuous sub-networks to establish a VPN.
Figure 203
Tunnel connecting discontinuous sub-networks
Internet
Novell IPX
Group1
IP
Term 1
Novell IPX
Group2
IP
Term 2
Tunnel
Router B
Router A
Router
r
r
Tunnel
Router
Router
Router
IP network
IP network
PC
PC
IP network
Tunnel
group2
novel
l
Router
Router
group 1
novell
IP network
VLAN
Summary of Contents for 3036
Page 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299 ...
Page 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721 ...
Page 6: ...2 ABOUT THIS GUIDE ...
Page 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface ...
Page 8: ...4 ...
Page 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION ...
Page 34: ...30 ...
Page 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT ...
Page 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS ...
Page 110: ...106 ...
Page 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW ...
Page 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE ...
Page 168: ...164 ...
Page 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT ...
Page 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1 ...
Page 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25 ...
Page 320: ...316 ...
Page 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS ...
Page 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION ...
Page 374: ...370 CHAPTER 23 CONFIGURING IP COUNT ...
Page 406: ...402 CHAPTER 25 CONFIGURING DLSW ...
Page 408: ...404 ...
Page 452: ...448 CHAPTER 29 CONFIGURING OSPF ...
Page 482: ...478 CHAPTER 30 CONFIGURING BGP ...
Page 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY ...
Page 502: ...498 ...
Page 508: ...504 CHAPTER 33 IP MULTICAST ...
Page 514: ...510 CHAPTER 34 CONFIGURING IGMP ...
Page 526: ...522 CHAPTER 36 CONFIGURING PIM SM ...
Page 528: ...524 ...
Page 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY ...
Page 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL ...
Page 590: ...586 CHAPTER 40 CONFIGURING IPSEC ...
Page 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE ...
Page 600: ...596 ...
Page 638: ...634 CHAPTER 43 CONFIGURING L2TP ...
Page 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP ...
Page 650: ...646 ...
Page 666: ...662 ...
Page 670: ...666 CHAPTER 47 QOS OVERVIEW ...
Page 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT ...
Page 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE ...
Page 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem ...
Page 708: ...704 ...
Page 762: ...758 CHAPTER 52 CONFIGURING MODEM ...