


ICMP (Internet Control Message Protocol) is a protocol used to transmit control messages and error reports in the network. It plays an important role in IP networks, helping network devices and hosts detect and troubleshoot connectivity issues. The functions of ICMP include communication between routers, monitoring of network connection status, and delivery of error reports. Through ICMP, network administrators can better understand the operating status of the network and solve potential problems in a timely manner to ensure the stability and reliability of the network.
-
Function of ICMP:
- Error reporting: When an IP packet error occurs during transmission, ICMP can generate an error report and return it to the source host so that the source host can take appropriate actions.
- Network status detection: ICMP provides a method for testing the host and network connection status. For example, the Ping command is implemented based on the ICMP protocol.
- Router notification: ICMP can also be used by routers to send various notifications, such as target unreachable, redirection, etc.
-
ICMP message format:
ICMP messages are usually encapsulated in IP packets and have the following basic format:0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Type | Code | Checksum |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Data |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- Type: Specify the type of ICMP message, such as echo request, echo reply, target unreachable, etc.
- Code: Provide more detailed information for the Type field.
- Checksum: used to check the integrity of ICMP messages.
- Data: Carrying additional data of specific types and codes.
-
Common uses of ICMP:
- Ping: Use ICMP echo request and echo reply messages to test the connection status and round-trip delay time between hosts.
- Traceroute: Use ICMP Time Exceeded messages to trace the router path a packet takes by sending IP packets with different TTL values to the destination host.
- Destination unreachable notification: When an IP packet cannot reach its destination, the network device will send an ICMP destination unreachable message to notify the source host.
ICMP is a vital protocol in network communications, mainly used to deliver control messages and error reports. It helps network administrators and developers with network connection status testing, error reporting, and router notifications. With ICMP, they can more effectively manage and diagnose network connectivity issues, ensuring network stability and reliability.
The above is the detailed content of Network communication protocol-ICMP protocol explained in detail!. For more information, please follow other related articles on the PHP Chinese website!

一、黑/白名单IP限制访问配置nginx配置黑白名单有好几种方式,这里只介绍常用的两种方法。1、第一种方法:allow、denydeny和allow指令属于ngx_http_access_module,nginx默认加载此模块,所以可直接使用。这种方式,最简单,最直接。设置类似防火墙iptable,使用方法:直接配置文件中添加:#白名单设置,allow后面为可访问IPlocation/{allow123.13.123.12;allow23.53.32.1/100;denyall;}#黑名单设置,

ip与mac绑定是指将特定的IP地址与特定的MAC地址关联起来,使得只有使用该MAC地址的设备才能够使用该IP地址进行网络通信。ip与mac绑定可以防止被绑定的主机的IP地址不被假冒,前提条件:1、MAC地址是唯一的,并且不可假冒;只能绑定与路由器直接相连的网络上的主机(也就是主机的网关在路由器上)。

微信查看ip地址的方法:1、登录电脑版微信,右键点击屏幕下方的任务栏,点击“任务管理器”;2、弹出任务管理器时,点击左下角的“详细信息”;3、任务管理器进入“性能”选项,点击“打开资源监视器”;4、选择“网络”,勾选微信进程“Wechat.exe”;5、点击下面的“TCP连接”即可监视微信网络IP相关情况,发送消息得到回复就会显示他人的IP地址。

1.设置目录白名单:对指定请求路径不设置限制,如对请求路径为api目录下的请求不做限制,则可写为server{location/app{proxy_passhttp://192.168.1.111:8095/app;limit_connconn20;limit_rate500k;limit_reqzone=fooburst=5nodelay;}location/app/api{proxy_passhttp://192.168.1.111:8095/app/api}}#因nginx会优先进行精准匹

引言nginx做反向代理时,默认的配置后端获取到的Ip地址都来自于nginx,用request.getRemoteAddr();获取到的是nginx的ip地址,而不是用户的真实ip.1.修改Nginx配置:server{listen80;server_namejenkins.local.com;location/{proxy_set_headerHost$host;proxy_set_headerX-Real-IP$remote_addr;proxy_passhttp://192.168.10.

本机ip地址查询的方法有:1、 Windows系统下,打开“开始菜单”并搜索“cmd”打开命令提示符,输入“ipconfig”,然后按回车键,查找名为“IPv4 地址”的一行,其旁边的数字就是本机的IP地址;2、macOS系统下,点击屏幕左上角的苹果图标,选择“系统偏好设置”,在“网络”选项中找到当前连接的网络,点击“高级”按钮,在“TCP/IP”选项卡中查找本机的IP等等。

wifi显示无ip分配的解决办法:1、重新启动设备和路由器,关闭设备上的Wi-Fi连接,关闭设备,关闭路由器,等待几分钟,然后重新打开路由器链接wifi;2、检查路由器设置,重启DHCP,确保DHCP功能已经启用;3、重置网络设置,将删除所有已保存的WiFi网络和密码,在执行此操作之前,请确保已备份;4、更新路由器固件,登录路由器管理界面,查找固件更新选项,并按照提示进行操作。

IP常见的含义有“IP地址”、“知识产权”、“独特卖点”和“独立性”四种:1、IP地址,是计算机网络中用于标识和定位设备的数字标识;2、知识产权,指人们的智力创造成果所享有的权益,包括专利、商标、版权和商业秘密等;3、独特卖点,是产品或服务的独特特点,使其与竞争对手区分开来并吸引顾客;4、独立性,指一个国家或地区拥有自主决策和自我管理的能力,不受外部控制或干涉。


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Dreamweaver Mac version
Visual web development tools

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

Notepad++7.3.1
Easy-to-use and free code editor

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

SublimeText3 Mac version
God-level code editing software (SublimeText3)
