解决手段:编写ACL规则探测程序,从公网扫描该网络设备的ACL规则工作原理:不管是交换机还是路由器或防火墙,在处理数据包时ACL规则总是优先于ICMP规则。即:当网络设备收到一个TTL为0的报文时会先匹配ACL规则之后再向发送者发送ICMPtime exceeded ICMP协议 文章目录 1.ICMP协议是干什么的2.ICMP协议的封装格式 1.ICMP协议是
The ICMP message type is identifiedA type field identifies ICMP messages in the ICMP header, which specifies the message type sent. Many ICMP message types exist, including Echo-Request, Echo-Reply, Time Exceeded, Destination Unreachable, and Redirect....
Configuring the IP Address of the Inbound Interface for Forwarding Packets as the Source Address of an ICMP Time Exceeded Message Forcibly Context Tracert is used to test the path through which a packet is sent from a host to the destination. After receiving the packet, an intermediate device ...
TTL (Time-To-Live) Expired: Every packet has a limited lifespan that we call the TTL value. If they are unable to reach their target, then they are dropped, and a Time Exceeded message (ICMP type 11) is reverted back. Fragment Reassembly Time Exceeded: This can occur when a packet is...
When a client receives this message, it will automatically slow down the outgoing data rate or wait for a sufficient amount of time, which enables the router to empty the queue. Thus the source quench ICMP message acts as flow control in the network layer. Source quench message [3]:9 00...
10.6.2 icmp_dest_unreach()目的不可达差错报告 10.6.3 icmp_time_exceeded()超时差错报告 10.7 接收ICMP报文处理 前言 参考:RFC 792 原文:李柱明博客:https://www.cnblogs.com/lizhuming/p/16861945.html 10.1 ICMP简介 IP 协议是一种不可靠、无连接的协议,只在各个主机间交付数据,但是对于数据的到达与否,IP...
by 1. If the TTL reaches 0 before the targeted destination host is “hopped,” the router drops the packet and sends anICMP Time Exceededmessage back to the original sender. This is like saying, “I couldn’t reach the device within the allocated TTL – which is defaulted to 30 hops....
By default, the function of sending ICMP Time Exceeded packet is enabled. Run undo icmp port-unreachable send The function of sending ICMP Port Unreachable packets is disabled. By default, the function of sending ICMP Port Unreachable packets is enabled. Run undo icmp host-unreachable send The ...
ICMP协议总结 ICMP是“Internet Control Message Protocol”(Internet控制消息协议)的缩写。 它是TCP/IP协议族的一个子协议,用于在IP主机、路由器之间传递控制消息。 控制消息是指网络通不通、主机是否可达、路由是否可用等网络本身的消息。 这些控制消息
Time ExceededA time-exceeded message is sent in two cases. Whenever a router reduces the TIL field in a data gram to zero. The router discards the datagram and sends a time exceeded message. In addition, a time exceeded message is sent by a host if the reassembly timer expires before all...