vpn icmp

bound with the domestic famous peanut shell dynamic Domain Name Service. Users can use the dynamic domain name resolution service of peanut shells to access through the dynamic IP address ADSL, it significantly reduces the cost of establishing a VPN network and becomes the preferred technology for VPN solution providers in multiple branches of small and medium-sized commercial networks in China. Other prot

Linux ICMP feature Analysis one ICMP protocol-related format The ICMP protocol is a very important protocol in the network layer, it is called the Internet Control Message Protocol (Internet controlling messaging Protocol), the ICMP protocol makes up the lack of IP, it uses IP protocol to transmit information, Provide

　　ICMP is an Internet Control Messaging Protocol (PROTOCOL). It is a child protocol of the TCP/IP protocol family that is used to pass control messages between IP hosts and routers. Control message refers to network communication, whether the host is up to, whether the route is available or not. Although these control messages do not transmit user data, they play an important role in the transfer of user data. 　　The function and characteristics of

In the analysis of the previous section, 3 questions were left: Before parsing the ICMP packet processing process, I have the following questions: 1. Why to create a socket for each CPU only to send ICMP messages, do not use the socket can also send ICMP messages out. 2. What is the working principle of ping? 3. What is the working principle of traceroute? 1, for

First, ICMP introduction The full name of ICMP is the Internet Control message Protocol (inter-Network Messaging protocol), an integral part of IP, used to provide error reporting. Once the various types of errors are found to return them to the original host, our most common ping command is based on ICMP. |-----------------------------------------| || ------

Linux original socket (2)-icmp request and receipt, linux-icmp I. Overview The previous arp request used the original socket of the link layer. Icmp is encapsulated in ip datagram, so icmp requests can directly use the original socket at the network layer, that is, the first parameter of socket () is PF_INET. As follow

Use ICMP tunneling technology for ICMP encapsulation and penetration Firewall 0x00 icmp Tunneling Technology ICMP tunneling technology, also known as Ping tunneling technology, we know that the ping protocol is icmp. When the firewall receives a protocol package, it is relea

through the peanut shell dynamic Domain name resolution services, using dynamic IP address ADSL access, significantly reduce the cost of building a VPN network, Become the preferred technology of the VPN solution provider for the domestic small and medium sized commercial network multiple branch offices. Other protocols and features include: NAT, ICMP, PPPoE, DH

ICMP is (Internet Control message Protocol) Internet controlled message protocol. It is a sub-protocol of the TCP/IP protocol family that is used to pass control messages between IP hosts and routers. The control message refers to the message that the network is not accessible, whether the host is available, whether the route is available, and so on. These control messages, while not transmitting user data, play an important role in the delivery of u

Rd and RT (mpls vpn bgp) Rd (route-distinguisher) is used to identify different VPN instances on the PE device. Its main function is to achieve address multiplexing between VPN instances. It and the IP address constitute a 12byte vpnv4 address space, rd and the route are carried together in the bgp update message and published to the peer end. On the one hand, we

I. Overview:I received A friend's question in my blog. After phone communication, I learned the approximate situation:. the headquarters has a leased line to partner B. the partner side is not convenient to add a back-to-point route. When the Headquarters accesses the partner, PATC is implemented. now, if you want to connect the branch L2L VPN to the headquarters and PAT to the partner, the traffic from the branch to the partner is routed to the loopb

I. Overview: 1. ICMP allows the host or route to report errors and provide relevant exceptions. ICMP is a standard protocol for the Internet, but ICMP is not a high-level protocol, but an IP layer protocol. Generally, ICMP packets are used by the IP layer or higher-level protocols (TCP or UDP. Some

label: SP Div art for using Ar data in style HTTP 一.概述： 1.ICMP同意主机或路由报告差错情况和提供有关异常情况。ICMP是因特网的标准协议，但ICMP不是高层协议，而是IP层的协议。通常ICMP报文被IP层或更高层协议（TCP或UDP）使用。一些ICMP报文把差错报文返回给用户进程。 2.ICMP报文作为IP层数据报的数据，加上数据报的首部，组成数据报发送出去。 3.

Swiss Army Knife protocol-ICMP ICMP protocol An important supplement to the IP protocol is the ICMP protocol. ICMP (Internet Control Message Protocol) is a Protocol between the network layer and the transport layer. Its main function is to transmit network diagnostic information.

Many people may misunderstand the ICMP protocol, especially in terms of security. So what do we think about ICMP security? We will discuss this issue in detail today. For more information, see the following section. 1. Security importance of ICMP The characteristics of the ICMP protocol determine that it is very easy t

): Iptables-a input-p gre-j ACCEPT iptables-a input-p tcp-m tcp--dport 1723-j ACCEPT iptables-a input-m STA Te--state related,established-j ACCEPT iptables-a forward-s 0/24-o eth0-j ACCEPT iptables-a forward-d 0/24 -I eth0-j ACCEPT iptables-t nat-a postrouting-s 0/24-o eth0-j Masquerade The above IP segment 192.168.0.1/24 may need to be modified to the Localip and REMOTEIP location IP segment that you configured in/etc/pptp.conf. There are a few other services that are neede

ICMP is one of the most important protocols in network protocols. It implements some effective message control to complete some transmission errors. So how should we understand this agreement? What is its workflow? Since the IP network is unreliable and cannot guarantee information transmission, it is important to notify the sender when a problem occurs. ICMP is a mechanism for providing network fault probl

Security is a problem that we can never ignore, especially network security, which is not easy to control. Let's talk about ICMP protocol security in detail, I hope you can refer to some of the content in this article. 1. Security importance of ICMP The characteristics of the ICMP protocol determine that it is very easy to be used to attack routers and hosts on t

ICMP redirection PrincipleICMP redirection is one of ICMP control packets. Under certain circumstances, when a router detects that a machine uses a non-optimized route, it will send an ICMP redirection packet to the host and request the host to change the route. The router also forwards the initial datagram to its destination.ICMP Application Analysis-

. If such ICMP messages are repeatedly sent, the device may become inaccessible to the network. The IETF document also outlines another DoS attack method that uses the path's largest transmission unit to discover PMTUD. PMTUD is a mechanism of ICMP to process error messages.Cisco indicates that only routers and other devices running IOS with PMTUD enabled are under this attack. It indicates that