2013年10月23日 · The ICMP 'ping' packet, officially known as 'echo request', contains whatever the originating ping executable wants to have echoed back to it. In the Bad Old Days when the internet was first getting started up, the routers they had (and all computers, really) were subject to random memory failures.

2020年1月8日 · はじめに ASA のインタフェースへ PING を実行した際に、ASA の ICMP トラフィック処理・制御について紹介します。本ドキュメントは、ASA バージョン9.8(4)15を用いて確認、作成しております。 デフォルト動作 デフォルト動作は、ASA のインターフェイスに着信するすべての ICMP トラフィックを許可し ...

2009年6月10日 · An ICMP echo-request message, which is generated by the ping command, is sent by any host to test node reachability across an internetwork. The ICMP echo-reply message indicates that the node can be successfully reached. An ICMP Redirect message is sent by the router to the source host to stimulate more efficient routing.

1 A TCP ping does not really exist as a ping is performed with ICMP on ISO/OSI layer 3. A TCP ping is performed on ISO/OSI layer 4. It just tries to connect to a TCP port in the most basic way, that it is not transmitting any data, but closing the connection immediately after connecting.

2024年3月23日 · Using ping in C# is achieved by using the method Ping.Send(System.Net.IPAddress), which runs a ping request to the provided (valid) IP address or URL and gets a response which is called an Internet Control Message Protocol (ICMP) Packet. The packet contains a header of 20 bytes which contains the response data from the server …

2017年12月29日 · Hello All, Is there a way that I can allow ICMP ping to a physical or virtual interface of a router and block all other pings. I know this can be achieved using ACL just by permitting the interface IP and block ICMP for all other IP's. But I need to configure this in many routers so wanted check i...

2008年10月10日 · ACL's are processed line by line from the start and your first line is denying icmp from anywhere. Note that icmp on it's own covers echo and echo-reply. You need to rewrite your access-list to . access-list 110 permit icmp host 10.10.1.1 any . access-list 110 permit icmp host 10.10.1.1 any echo-reply . access-list 110 permit icmp host 10.10.1 ...

2019年1月5日 · There are many articles out there about ICMP and PING. This article solely focuses on ICMP traffic passing through Adaptive Security Appliance. With the default configurations ASA will allow a host to ping the interface which is connected to. However, ping from an internal host to the internet would...

2013年11月28日 · Here's documentation on how to compute the checksum of an ICMP header. ICMP Header Checksum. 16 bits. The 16-bit one's complement of the one's complement sum of the ICMP message, starting with the ICMP Type field. When the checksum is computed, the checksum field should first be cleared to 0.

2007年9月5日 · Hi, I tried to ping an ethernet interface in router in another site and I got the following: router# ping ...