gre lessons

GREs (Generic Routing protocol encapsulation) were submitted to IETF by Cisco, net-smiths, and other companies on September 10, 1994, marked as rfc1701 and rfc1702. Currently, most network devices support the GRE tunnel protocol.GRE specifies how to use one network protocol to encapsulate another network protocol. The GRE tunnel is defined by the source IP address and destination IP address at both ends. Yo

to the computer room intranet. Do you let each user dial a VPN? Very sad urge, still not good management. Here are two scenarios:1, point-to-end VPN scheme (after the successful erection, you can set as an end-to-end scenario), before writing an article, specifically, the "Startup office network security and Stability access to the computer room network solution 1:byvpn"http://h2ofly.blog.51cto.com/6834926/15298882, GRE program. This scenario is reco

650) this. width = 650; "src =" http://www.bkjia.com/uploads/allimg/131227/04242L605-0.jpg "title =" GRE.jpg "alt =" 140403257.jpg"/> GRE Configuration R1ConfigurationInterface Loopback1Ip address 192.168.3.1 255.255.255.0Ip ospf network point-to-pointInterface Loopback2Ip address 192.168.4.1 255.255.255.0Ip ospf network point-to-pointInterface Tunnel 1 // create GRE Tunnel 1Ip address 192.168.0.1

(0) The Turnel of GRE1. This process is the process of establishing turnel on both sides.(1) LAN routing process1, host A to send a source of 192.168.1.2, the purpose of 10.1.1.2 package(2) Packaging process1, depending on the internal network, may be your default route gateway to route it to 192.168.1.2542, 192.168.1.254 the first package package, increase the GRE header, the purpose of the package is the address 192.192.192.1 and the source address

GRE (Generic Routing Encapsulation) Overview GRE is one of the most traditional tunneling protocols, and its fundamental function is to realize the tunnel function, the two remote networks connected through the tunnel are like direct-attached, GRE, which simulates a direct link between two remote networks to achieve direct connectivity, and for this reason the

Creating an IP tunnel using GRE on Linux Contents [Hide]· 1 IP tunelling· 2 Starting Configuration· 3 tunnelling ObjectiveO 3.1 Create TunnelsO 3.2 Additional RoutesO 3.3 Delete Tunnels· 4 Network DiagramO 4.1 Debian Configuration· 5 References IP tunelling We'll do IPv4 tunneling using GRE. GRE is a tunneling protocol this was origin

The tunnel, literally, is a passageway, which is made up of point-to, stand-alone and other. The tunnels under Linux are not well understood, write down the recently built GRE tunnels and route forwarding functions.Let's talk about the basic concepts of tunnels:The interconnection of two or more subnets of a technology (protocol) or strategy through another technology (protocol) or policy, called overlay topology, is one of the timeless themes of tele

Companies in China, Japan, the United States, Germany, Singapore and many other businesses have business, intermediary business Network with the company's proprietary GPN (Global Private Network Chinese name is the world's privatization networks) link, the current test to build a backup link for network redundancy and failover.The initial selection program is GRE over IPSEC, which runs the OSPF routing protocol.First, why to choose

Anyone who has some knowledge about networking must know tunnel encapsulation technology. In the network, we use the GRE protocol to encapsulate data packets. So today we will have a basic understanding of this agreement. Next, let's look at the text. 1. Protocol Introduction The GRE (generic routing encapsulation, universal routing encapsulation) protocol encapsulates the datagram of some network layer pro

The GRE protocol is used to build a channel that passes through the public Internet, so that non-IP traffic based on protocols that cannot publish routes can reach their destination. To attack hosts on the internal network, you need to know the external IP addresses of the two terminals that provide the GRE tunnel and the internal IP addresses of the hosts you want to attack. This can be achieved through mu

　　May 11, there was nothing in the mind for a day. The GRE exam 10th was finished. Finally left the examination room at that moment, everyone has already left, and I sit there slowly choose the school, free to send points, why not, choose Mit,cit,ucla,michigan, four world Top20 even TOP10 inside of the university.first, the test day AW should be able to get at least 5 points at the end, Because luck is met is the more fully prepared by their own

I. Networking requirementsRouter H3C A and router H3C B are connected over the Internet. Two private subnets, Group 1 and Group 2, are interconnected through a GRE tunnel between the two routers. 2. The following figure shows the network topology. 650) this. width = 650; "border =" 0 "alt =" "src =" http://www.bkjia.com/uploads/allimg/131227/02230QQ8-0.jpg "/> 3. configuration steps Before starting the following configuration, make sure that the route

650) this. width = 650; "src =" http://www.bkjia.com/uploads/allimg/131227/050333CX-0.png "title =" Traditional gre over ipsec ))).png "/> This article continues to discuss gre over ipsec above. The last time we established the IPSec connection transport mode between the two sites), then we established the gre tunnel on the IPSec connection for encrypted communi

First, Environment constructionRouter A Intranet address 10.1.1.1/24 through the public address 1.1.1.1/24 package and then walk the tunnel 10.1.2.1/24Router B Intranet address 10.1.3.1/24 through the public address 2.2.2.2/24 package and then walk the tunnel 10.1.2.2/24If the experiment in GNS3 can be loopback port as the intranet address, the Internet with the route simulation but can not afford to route only Ip,router A and Router B are the default route to the Internet, so that the public ne

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For Network Protocol Transmission in different environments, we need to encapsulate it in the form of mail packaging. This is also the role of the GRE protocol. Let's take a look at the specific content encapsulated by the Protocol. Hope to help you. 1. GRE protocol Concept Generic Routing Encapsulation (GREGeneric Routing Encapsulation) encapsulates packets of certain network layer protocols such as IP and

Today, I encountered a very interesting topic, recursive routing. Although gre over ipsec is configured, the routing interface is down back and forth, * Mar 4 15:08:34. 435: % OSPF-5-ADJCHG: Process 10, Nbr 4.4.4.4 on Tunnel0 from LOADING to FULL, Loading Done * Mar 4 15:08:42. 003: % TUN-5-RECURDOWN: Tunnel0 temporarily disabled due to recursive routing* Mar 4 15:08:43. 003: % LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to d

GRE in tunneling (packets transmitted in the GRE tunnel have 3 IP addresses)1, establish a virtual direct-connect route, can be considered as a tunnel, analog link1, receive the original IP packet as a passenger agreement, the IP address of the original IP packet header is a private IP address2, the original IP Packet Encapsulation GRE protocol, the

CCNA Experiment 36 GRE(Generic route encapsulation)Environment: Windows XP ,Packet Tracert5.3Objective: To understand Use of GRE to master How to configure GRE. DescriptionGRE (Generic Routing encapsulation, Generic Routing Encapsulation) protocol is the encapsulation of data packets for certain network layer protocols, such as IP and IPX, so that these encapsula

protocol {GRE IPSec} Classification of VPN 1.VPDN dial-up VPN PPTP L2TP stand-alone---network (user VPN) 2. Private Line VPN Network---Network (Enterprise network VPN) In this blog to achieve a small part of the first to implement a three-layer protocol GRE VPN, in the future of the article will also implement IPSec VPN Configuration tasks: 1. Create an interface Interface Tunnel number Tunnel-prot