tcp ip illustrated volume 2

TCP Learning Record (from TCP/IP Volume 1) tcp's TIME_WAIT status TCP requirements, first issue the FIN end, after both parties completely close the connection, the maximum message segment survival time (MSL) remains in the TIME_WAIT status until two times ). The recommended

Finally, we finally came to the large header TCP protocol. In order to provide reliable transmission services for the application layer, various mechanisms are designed for tcp to achieve possible errors during transmission, such as packet loss, retransmission, disordered order, and link transmission errors. 1. TCP Overview First, let's take a look at the header

) the Ifconfig (8) command is typically run at boot time to configure each interface on the host. Because the dial-up interface may be plugged in and out frequently (such as a slip link), the ifconfig must run in some way each time the line is switched on and off. How this process is done depends on the slip software used.(2) the Netstat (1) command provides the interface information on the system. The-I parameter prints out the interface information,

completely replaces B. What follows is like an intruder's mood. In this sense, any machine's Sniffer can be used to track all communication data ). As mentioned above, I still only have an understanding of the concept and principle and a summary of these aspects. It is not enough to achieve the level of practice. Network Packet Capture is now available, but it is still early to talk about protocol analysis. It is difficult to even construct RAW Socket. If you want to use other methods, it is ev

TCP needs to process two types of data at the same time: block data, interactive data.This chapter will take the Rlogin application as an example to observe the transfer process of interactive data.Interactive inputFirst, the flow of data generated by typing an interactive command on a rlogin connection (each typing an interactive key produces a data grouping), which results in 4 segments:1. Interactive keys from the customer;

a host or a simple routing algorithm for it. essentially the difference is that the host never forwards the datagram from one interface to another, while the router forwards the datagram. The host that contains the router function should never forward datagrams unless it is set to that.In a general system, IP can accept datagrams from tcp,udp,icmp and IGMP (i.e. locally generated datagrams) and send them,

"TCP/IP Detailed Volume 1: Agreement" 1th Chapter Overview-Reading Notes"TCP/IP Detailed Volume 1: Protocol" chapter 2nd link layer-Reading notes"TCP/

headquarters minus the length of the TCP header. The UDP test and (optional) overwrite the UDP header and UDP data. The calculation method is the same as the IP header test and calculation method. If the UDP data is an odd byte, it is filled with a byte of 0. during calculation, the UDP pseudo-header will be added before the UDP header to check whether the data has arrived at the destination correctly twic

protocol is independent of the IP address, there is no network layer settings, only the physical layer and the link layer, initially only the hub, no switch router, the server between the transfer of data by MAC address. The MAC address is already in use before the IP address is available. The two-layer switch, which is now used everywhere, is to forward data based on the MAC address. The reason for th

layer checks and computes the packet to determine whether to deliver or discard the packet, and then uses the "protocol" field in the ip header to determine whether the packet is a UDP datagram, TCP segment, ICMP, or IGMP packet, in this way, IP datagram is used separately. If it is ICMP or IGMP, it will be processed according to the protocol. If it is

Chapter Review:"TCP/IP Detailed Volume 1: Agreement" 1th Chapter Overview-Reading Notes1. IntroductionAs can be seen from figure 1-4, in the TCP/IP protocol family, the link layer has three main purposes:(1) send and receive IP da

end of the datagram (end character 0xc0) Point-to-Point Protocol PPPThe defect of slip has been modified. Loopback interface (Loopback Interface)Allow client programs and service programs running on the same host to communicate over TCP.Most systems assign 127.0.0.1 to this interface and are named localhost. An IP datagram passed to the loopback interface cannot appear on any network. Maximum Transmission Unit MTUEthernet and 802.3 have a limit

"TCP/IP Detailed Volume 1: Protocol" chapter 6th icmp:internet Control Message Protocol---reading notes1. IntroductionICMP is considered to be an integral part of the IP layer, which transmits error messages and other information that needs attention. ICMP packets are typically used by the

the Ethernet receive this frame and check the target address. If the target address and network adapter address are the same, the adapter software processes the received frame and transmits the data to the higher layer in the protocol stack. Chapter 2 Internet Layer Addressing and sending-- In a selected route network, the TCP/IP software uses the following p

address,How to communicate? ) 2) There is no Type field in the data frame, and if one line is used for slip it cannot use other protocols at the same time; 3) There is no check field in slip, and once transmitted packets are affected by line noise, errors can only be found through the upper layer protocol. because of the speed of the serial line of the foot, and communication is usually interactive, so there are many small

the ICMP Destination Unreachable messages. The ICMP unreachable message is shown in the general format 6-10.Description(1) One rule of ICMP is that the ICMP error message must include the datagram IP header that generated the error message (including any options), and must include at least the first 8 bytes following the IP header.(2) the

destined for a given multicast address, and the device driver must be able to receive these multicast frames. This process is "join a multicast Group" (multiple receivers exist on the same host or multiple hosts). When a host receives multicast data, he must send a replication to each process that belongs to that multicast group , which differs from the UDP that a single process receives for unicast UDP datagrams. with multicasting, there may be multiple processes on one host that belong to the

"TCP/IP Detailed Volume 1: Protocol" chapter 5th RARP: Reverse Address Resolution Protocol---reading notes1. IntroductionWhen a system boots with a local disk, the IP address is typically read from the configuration file on disk. However, diskless machines, such as x terminals or diskless workstations, require addition

across network segments.10, usually the host needs to maintain a table for multicast, the contents of the table has the multicast address and the corresponding network interface (multicast address and network interface binding) and the number of processes to join the corresponding multicast. Whenever a process joins a new group, the host sends a notification from the appropriate network interface informing the multicast router and other multicast hosts, but subsequent process re-entry and any p

The data link, such as Ethernet, has its own addressing mechanism (MAC) address, and the IP layer uses an IP address.When a host sends Ethernet data to another host on the same LAN, the destination interface is determined based on the MAC address. The device driver never checks the destination IP address in the IP data