how to packet sniff network

of processes because grep itself is a process. Four: View network status To print information such as network connection status, ports that are open to the system, routing tables, and so on. Common commands: NETSTAT-LNP print which ports the current system launches Netstat-an Print network connection status Tips: Netstat-an |awk '/^tcp/{++sta[$NF]} END

In fact, it has been a long time to explore the problem of network card packet capture. I found some basic things in the last few days. I will just repeat them here. Packet Capture first needs to know that the data transmitted through the NIC is actually through the underlying link layer (MAC). in Linux, the data traffic we obtain from the NIC is actually directl

Linux Network Application Programming Packet Tracer installation and interface introduction, packettracerIntroduction to Packet Tracer 1 Packet tracer is an auxiliary learning tool released by Cisco. It provides a network simulation environment for beginners of Cisco

Qt packet abstraction based on TCP network program I have no experience before. When sending data packets, the packet header and other information are all implemented by redefining a struct. Different protocol packages have different structs. The result is as follows: how many upper-layer business protocol packages are there? I will re-define a new structure corr

Packet Tracer Introductory One, Packet tracer introductionPacket Tracer is an assistive learning tool released by Cisco, which provides a network simulation environment for beginners in learning Cisco Web courses to design, configure, and troubleshoot network failures. The user can set up the

Clone Zabbix's own template ICMP ping templates 650) this.width=650; "Src=" Http://s5.51cto.com/wyfs02/M01/86/F3/wKioL1fPrcLi2YxjAAByYarcCOM203.jpg-wh_500x0-wm_3 -wmp_4-s_2806794333.jpg "title=" ping 202.96.209.5.jpg "alt=" Wkiol1fprcli2yxjaabyyarccom203.jpg-wh_50 "/>Here I make a network delay template to 202.96.209.5 Shanghai DNS650) this.width=650; "Src=" Http://s3.51cto.com/wyfs02/M02/86/F3/wKioL1fPrnnS2DkyAACNTuKAcik725.jpg-wh_500x0-wm_3 -wm

Solution 1: Disable all switches in the LAN five minutes later. Power on again to check if the network is back to normal! (Cause: it may be that the switch has used up its memory for a long time without restarting, resulting in slow data exchange speed or congestion caused by network storms) (another possible cause is that one or more interface modules of a vswitch are damaged, or an internal

This article introduces some programming of the original socket (raw socket) implemented by C # in Windows Sockets and the network packet Monitoring Technology Based on this. Compared with winsock1, Winsock2 supports the raw socket type most obviously. Using raw socket, you can set the NIC to the hybrid mode. In this mode, we can receive the IP packet on the

viewing UDP packet datasudo tcpdump UDP | grep 18060Tcpdump-i eth1 ' Port 18060 '#指定端口打印详情命令 (Eth1 on behalf of the network card number)Tcpdump-vv-x-x-s 1500-i eth1 ' Port 18060 '#指定端口抓包 and write filesTcpdump-i eth0 Port 18070-w dump.pcap#指定ip抓包 and write filesTcpdump-i eth0 host 10.30.17.21-w Dump.pcap#指定ip和端口抓包Tcpdump-i eth0 host 10.30.17.21 and Port 18070-w dump.pcapPackage parsingWireshark Analysis Pca

Using the original socket to implement a simple acquisition network packet and reverse parsing IP,MAC address # include #include #include #include #include #include #define BUFFER_MAX 2048int main (int argc, char **argv){int rawsock;Char Buffer[buffer_max];Char *ethhead;Char *iphead;Char *phead;Creating the original socketif ((Rawsock=socket (Pf_packet,sock_raw,htons (ETH_P_IP))) printf ("Error:create raw s

The so-called zero copy means that there will be no inter-memory copy during the packet sending and receiving process of a node. When the packet is sent, the user buffer of the application will directly go through the network interface to reach the external network, when receiving, the

more than 1000 lattice. The space capacity of each lattice is limited. When large data needs to be stored, the whole capacity is sufficient, but the capacity of the small lattice is not enough. At this point, there will be a problem of packet loss. It appears that memory is sufficient at this time, but there is no contiguous space in memory to store the data at this time. So these seemingly large available memory, in fact, can not save much data.

Packet Tracer 5.2 Experiment (15) network port address translation NAPT configurationFirst, the experimental target Understand the principle and function of NAT network address translation; Master NAPT configuration, realize LAN access to the Internet; Second, the experimental backgroundCorporate office netw