traceroute icmp

What is icmp redirection ICMP redirection is one of the 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 d

Preface Java is a cross-platform language. Generally, network operations are performed at or above the IP layer, that is, only tcp/udp operations can be performed. Of course, you can also set some options for tcp/udp, if you want to perform operations on the IP layer or data link layer, you can do nothing. You must rely on jni to use the socket interfaces of the local OS. Fortunately, I know that someone is developing jpcap when I know winpcap. This package allows you to conveniently operate the

In ICMP applications, network attacks have always been the focus of our attention. I believe that every administrator will not relax in this regard. So what are the characteristics of the protocol attacks? How can we prevent it? The following is a detailed analysis. ICMP attacks Although the ICMP protocol gives hackers the opportunity,

Author: Yi shoulong The full name of ICMP is Internet Control and Message Protocal, which is the Internet Control Message/error Message protocol. It works at the network layer and is a communication protocol for IP addresses, the main purpose is to report errors and status messages between hosts and devices on the network. The most common ICMP application is ICMP

There are three main types of network attacks by using ICMP Packets: Death Ping, ICMP DoS attacks, and redirection-based route spoofing. I. Death Ping 1.1 attack principle-limits the length of Ethernet packets, ultra-large packet networks adopt multipart transmission. The first part after a packet is split only contains the length of each part. The receiving end reassembles the received part message. The to

These two days in an experiment need to construct their own IP header, encountered a lot of problems, a day finally fix.Introduction to the socket on the internet a lot of, I only record the construction of the IP header when I encountered problems. Because did not play the socket constructs the IP header, looked for the paragraph code research on the net, helpless code to run, all sorts of problems, the net collects the data to have no fruit, from the foundation study, adds own brain hole final

TCP/IP Note 2. Network Layer (2) -- ICMP, RIP, OSPF, BGP 1. ICMPICMP (Internet Control Message Protocol): improves the chances of successful IP datagram delivery. 1.1 features ICMP allows the host or router to report errors and reports exceptions. ICMP is not a high-level protocol, but an IP layer protocol. An ICMP pac

TCP will not cause IP sharding, while UDP and ICMP will cause IP sharding. Why does TCP not cause IP sharding? The reason is that TCP itself supports segmentation: when TCP needs to transmit data with a length greater than the MSS (Maxitum Segment Size), it first segments the data. Normally, the MSS is smaller than the MTU. Therefore, TCP generally does not cause IP fragmentation. UDP and ICMP do not suppor

ICMP Protocol (Internet Control Message Protocol) 1.1. Definition: A protocol used by a host or router to send error or query information to a source point.1.2. Message structure IP Header ( up to four bytes)Note: TheICMP message is encapsulated in the IP packet, so include the IP header Type of message (2 bytes) Report Text field (2 bytes) Checksum (4 bytes)

Internet Control Message protocol,icmp is one of the core protocols of the network protocol family. It is used for sending control messages in TCP/IP networks, providing feedback on various issues that may occur in the communication environment, through which the manager can diagnose the problems that occur and then take appropriate action to resolve them.ICMP is typically used to return an error message or to parse a route. The

ICMP protocolIP does not provide a reliable transport service, nor does it provide end-to-end or point-to-point acknowledgement, which is implemented in the IP module if an error can be seen through the ICMP report. The TCP/IP protocol designs ICMP to compensate for the lack of IP protocol.It is a sub-protocol of the TCP/IP protocol family for use in IP hosts. Ro

The ICMP packet sent from client C to server s is intercepted when it passes through the local p. The previous article describes how to obtain the original destination address. You must forward the data to the original destination address S, and forward the response from the original destination address to the client. To implement transparent proxy, the source address of the ICMP response you return to the

Internet Control Information Protocol (ICMP)　IntroducedIn a system called Catenet, the IP protocol is used as a host to the host datagram service. A network connection device is called a gateway. These gateways exchange information for control through gateways to Gateway protocols (GGP). Typically, a gateway or destination host communicates with the source host, for example, for reporting errors in the datagram process.

(i) ICMPIP is an unreliable protocol, and IP does not provide error control (if the data is in error during propagation), this time ICMP is working.ICMP provides two functions: Error reporting, querying.ICMP ICMP packets are divided into two categories, one is error message, and the other is query message.ICMP target unreachable: That is, there is no way to send IP packets to the corresponding destination a

field is MF (more Fragment) Mf=1 indicates "There are shards" later. Mf=0 represents the Last Shard Df The one in the middle of the Flag field is DF (Don ' t Fragment) Shards are allowed only when df=0 Chip Offset:Occupies 12 bits, which refers to the relative position of a piece in the original group after the Shard. Slice offset in 8-byte offset unitsSurvival time:The maximum number of routers that are recorded as TTL (Time to Live) datagrams in th

MTUIdentity:Occupies 16 bits, it is a counter that is used to generate the identity of the datagramLogo (flag):3-bit, currently only the first two bits have meaning Mf The lowest bit of the Flag field is MF (more Fragment) Mf=1 indicates "There are shards" later. Mf=0 represents the Last Shard Df The one in the middle of the Flag field is DF (Don ' t Fragment) Shards are allowed only when df=0 Chip Offset:Occupies 12 bits, which