Header checksum

Header checksum

Header Checksum refers to the basic protection used in the header of IP packets against data corruption. This checksum is calculated only for the header bytes and is 16 bit long and is a part of the IP packet header.

This checksum is calculated by word aligning the IP header bytes and forming a ones complement of that. At every node of the router, the checksum is verified. The result should be all 1's if there is no corruption. At each hop, the checksum is recalculated and the packet will be discarded upon checksum mismatch.The router may add incremental IP header checksum updating when the only change to the IP header is the time to live. [ cite web |url=http://www.freesoft.org/CIE/RFC/1812/52.htm |title=Header Checksum: RFC 791 Section 3.1 |date= September, 2004|accessdate=2007-12-17]

See also

* Header Check Sequence

External links

* [http://www.tcpipguide.com/free/t_IPDatagramGeneralFormat.htm IP Datagram General Format]
* [http://everything2.com/index.pl?node_id=441121 Header Checksum]

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • IP-Header — Das IP Paket oder exakt Internet Protocol Datagram ist das Grundelement der Internet Datenkommunikation. Es besteht immer aus zwei Teilen: den Kopfdaten, die Informationen über Quelle, Ziel, Status, Fragmentierung etc. enthalten, und den… …   Deutsch Wikipedia

  • TCP-Header — TCP (Transmission Control Protocol) Familie: Internetprotokollfamilie Einsatzgebiet: Zuverlässiger bidirektionaler Datentransport TCP im TCP/IP‑Protokollstapel: Anwendung HTTP SMTP … Transport …   Deutsch Wikipedia

  • Tcp checksum offload — is an option for a network adapter. If enabled, the adapter would be responsible of computing the checksum of the incoming or outcoming TCP messages, resulting the calculation reduce of the CPU. With the option enabled, the system would give a… …   Wikipedia

  • HCS — Header Checksum …   Acronyms

  • HCS — Header Checksum …   Acronyms von A bis Z

  • Error detection and correction — In mathematics, computer science, telecommunication, and information theory, error detection and correction has great practical importance in maintaining data (information) integrity across noisy channels and less than reliable storage… …   Wikipedia

  • Network address translation — NAT redirects here. For other uses, see Nat (disambiguation). In computer networking, network address translation (NAT) is the process of modifying IP address information in IP packet headers while in transit across a traffic routing device. The… …   Wikipedia

  • IP-Paket — Das IP Paket oder exakt Internet Protocol Datagram ist das Grundelement der Internet Datenkommunikation. Es besteht immer aus zwei Teilen: den Kopfdaten, die Informationen über Quelle, Ziel, Status, Fragmentierung etc. enthalten, und den… …   Deutsch Wikipedia

  • IP fragmentation attacks — In computer networking the process of breaking up a single IP datagram into two or more IP datagrams of smaller size is called IP fragmentation. This comes from the fact that every datalink medium has a limit on the size of the transmitting frame …   Wikipedia

  • IP in IP — [http://www.faqs.org/rfcs/rfc2003.html] IP tunneling uses IP in IP protocol to encapsulate the IP packet in another IP packet. To encapsulate IP packet in a IP packet, an outer header is added with SourceIP, the entry point of the tunnel and the… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”