Which first 8 bytes of the IP datagram are included in ICMP message?
The definition of ICMP message says that it has a type, a code and the first 8 bytes of IP datagram causing error.
Question: Which first 8 bytes of IP datagram are included in the ICMP datagram?
My understanding: The portion marked by the red box in the figure below.
icmp
asked Dec 8 at 20:46
Banghua Zhao
222111
add a comment |
The definition of ICMP message says that it has a type, a code and the first 8 bytes of IP datagram causing error.
Question: Which first 8 bytes of IP datagram are included in the ICMP datagram?
My understanding: The portion marked by the red box in the figure below.
icmp
asked Dec 8 at 20:46
Banghua Zhao
222111
add a comment |
The definition of ICMP message says that it has a type, a code and the first 8 bytes of IP datagram causing error.
Question: Which first 8 bytes of IP datagram are included in the ICMP datagram?
My understanding: The portion marked by the red box in the figure below.
icmp
asked Dec 8 at 20:46
Banghua Zhao
222111
The definition of ICMP message says that it has a type, a code and the first 8 bytes of IP datagram causing error.
Question: Which first 8 bytes of IP datagram are included in the ICMP datagram?
My understanding: The portion marked by the red box in the figure below.
icmp
icmp
asked Dec 8 at 20:46
Banghua Zhao
222111
asked Dec 8 at 20:46
Banghua Zhao
222111
asked Dec 8 at 20:46
Banghua Zhao
222111
asked Dec 8 at 20:46
Banghua Zhao
222111
asked Dec 8 at 20:46
Banghua Zhao
222111
222111
add a comment |
add a comment |
2 Answers
2
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oldest
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Well, the sender might like to know which ones of its packets the ICMP message refers to. For that, the entire IP header plus (at least) the first eight bytes of the IP payload are appended to the ICMP header for error messages.
answered Dec 8 at 21:02
Zac67
25.4k21352
add a comment |
I am not sure what definition you are referring to (source?), but it probably meant a 8 bit.
An ICMP packet is 8 bytes total[1], the first 16 bits are type and code bytes(eight bits in a byte); the type byte is given a number from 0 to 255[2], a different number representing a different type of sub-code.
As Zac67 stated the sender usually likes to know where the ICMP packet comes from, so it encapsulates it in an IP header, that IP header contains a field called 'protocol' when an ICMP packet is carried in the payload the protocol field is set[3] to 1 (0x01 in hex or 00000001 in binary), the protocol field is also bits (1 byte) long.
Below is some useful resources and sources.
Hope this helps.
https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
http://slideplayer.com/slide/3602717/
http://www.enterprisenetworkingplanet.com/netsp/article.php/3584166/Networking-101-Understanding-and-Using-ICMP.htm
http://www.pearsonitcertification.com/articles/article.aspx?p=1804873
[1] - http://www.keyboardbanger.com/wp-content/uploads/2015/07/ICMP-header.png
[2] - https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Control_messages
[3] - https://en.wikipedia.org/wiki/List_of_IP_protocol_numbers
answered Dec 9 at 21:09
Xuebit
1
2
The real definition of ICMP is RFC 792, Internet Control Message Protocol. An ICMP message can certainly be longer than eight total bytes. In fact, it will include the IP header (20 bytes for IPv4) and the first 64 bits (eight bytes) of the IP payload: "The internet header plus the first 64 bits of the original datagram's data." That is enough to include the source and destination addresses of protocols like TCP or UDP.
– Ron Maupin♦
Dec 9 at 21:17
add a comment |
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2 Answers
2
active
oldest
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2 Answers
2
active
oldest
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active
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active
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votes
Well, the sender might like to know which ones of its packets the ICMP message refers to. For that, the entire IP header plus (at least) the first eight bytes of the IP payload are appended to the ICMP header for error messages.
answered Dec 8 at 21:02
Zac67
25.4k21352
add a comment |
Well, the sender might like to know which ones of its packets the ICMP message refers to. For that, the entire IP header plus (at least) the first eight bytes of the IP payload are appended to the ICMP header for error messages.
answered Dec 8 at 21:02
Zac67
25.4k21352
add a comment |
Well, the sender might like to know which ones of its packets the ICMP message refers to. For that, the entire IP header plus (at least) the first eight bytes of the IP payload are appended to the ICMP header for error messages.
answered Dec 8 at 21:02
Zac67
25.4k21352
Well, the sender might like to know which ones of its packets the ICMP message refers to. For that, the entire IP header plus (at least) the first eight bytes of the IP payload are appended to the ICMP header for error messages.
answered Dec 8 at 21:02
Zac67
25.4k21352
edited Dec 9 at 21:26
answered Dec 8 at 21:02
Zac67
25.4k21352
answered Dec 8 at 21:02
Zac67
25.4k21352
answered Dec 8 at 21:02
Zac67
25.4k21352
25.4k21352
add a comment |
add a comment |
I am not sure what definition you are referring to (source?), but it probably meant a 8 bit.
An ICMP packet is 8 bytes total[1], the first 16 bits are type and code bytes(eight bits in a byte); the type byte is given a number from 0 to 255[2], a different number representing a different type of sub-code.
As Zac67 stated the sender usually likes to know where the ICMP packet comes from, so it encapsulates it in an IP header, that IP header contains a field called 'protocol' when an ICMP packet is carried in the payload the protocol field is set[3] to 1 (0x01 in hex or 00000001 in binary), the protocol field is also bits (1 byte) long.
Below is some useful resources and sources.
Hope this helps.
https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
http://slideplayer.com/slide/3602717/
http://www.enterprisenetworkingplanet.com/netsp/article.php/3584166/Networking-101-Understanding-and-Using-ICMP.htm
http://www.pearsonitcertification.com/articles/article.aspx?p=1804873
[1] - http://www.keyboardbanger.com/wp-content/uploads/2015/07/ICMP-header.png
[2] - https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Control_messages
[3] - https://en.wikipedia.org/wiki/List_of_IP_protocol_numbers
answered Dec 9 at 21:09
Xuebit
1
2
The real definition of ICMP is RFC 792, Internet Control Message Protocol. An ICMP message can certainly be longer than eight total bytes. In fact, it will include the IP header (20 bytes for IPv4) and the first 64 bits (eight bytes) of the IP payload: "The internet header plus the first 64 bits of the original datagram's data." That is enough to include the source and destination addresses of protocols like TCP or UDP.
– Ron Maupin♦
Dec 9 at 21:17
add a comment |
I am not sure what definition you are referring to (source?), but it probably meant a 8 bit.
An ICMP packet is 8 bytes total[1], the first 16 bits are type and code bytes(eight bits in a byte); the type byte is given a number from 0 to 255[2], a different number representing a different type of sub-code.
As Zac67 stated the sender usually likes to know where the ICMP packet comes from, so it encapsulates it in an IP header, that IP header contains a field called 'protocol' when an ICMP packet is carried in the payload the protocol field is set[3] to 1 (0x01 in hex or 00000001 in binary), the protocol field is also bits (1 byte) long.
Below is some useful resources and sources.
Hope this helps.
https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
http://slideplayer.com/slide/3602717/
http://www.enterprisenetworkingplanet.com/netsp/article.php/3584166/Networking-101-Understanding-and-Using-ICMP.htm
http://www.pearsonitcertification.com/articles/article.aspx?p=1804873
[1] - http://www.keyboardbanger.com/wp-content/uploads/2015/07/ICMP-header.png
[2] - https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Control_messages
[3] - https://en.wikipedia.org/wiki/List_of_IP_protocol_numbers
answered Dec 9 at 21:09
Xuebit
1
2
The real definition of ICMP is RFC 792, Internet Control Message Protocol. An ICMP message can certainly be longer than eight total bytes. In fact, it will include the IP header (20 bytes for IPv4) and the first 64 bits (eight bytes) of the IP payload: "The internet header plus the first 64 bits of the original datagram's data." That is enough to include the source and destination addresses of protocols like TCP or UDP.
– Ron Maupin♦
Dec 9 at 21:17
add a comment |
I am not sure what definition you are referring to (source?), but it probably meant a 8 bit.
An ICMP packet is 8 bytes total[1], the first 16 bits are type and code bytes(eight bits in a byte); the type byte is given a number from 0 to 255[2], a different number representing a different type of sub-code.
As Zac67 stated the sender usually likes to know where the ICMP packet comes from, so it encapsulates it in an IP header, that IP header contains a field called 'protocol' when an ICMP packet is carried in the payload the protocol field is set[3] to 1 (0x01 in hex or 00000001 in binary), the protocol field is also bits (1 byte) long.
Below is some useful resources and sources.
Hope this helps.
https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
http://slideplayer.com/slide/3602717/
http://www.enterprisenetworkingplanet.com/netsp/article.php/3584166/Networking-101-Understanding-and-Using-ICMP.htm
http://www.pearsonitcertification.com/articles/article.aspx?p=1804873
[1] - http://www.keyboardbanger.com/wp-content/uploads/2015/07/ICMP-header.png
[2] - https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Control_messages
[3] - https://en.wikipedia.org/wiki/List_of_IP_protocol_numbers
answered Dec 9 at 21:09
Xuebit
1
I am not sure what definition you are referring to (source?), but it probably meant a 8 bit.
An ICMP packet is 8 bytes total[1], the first 16 bits are type and code bytes(eight bits in a byte); the type byte is given a number from 0 to 255[2], a different number representing a different type of sub-code.
As Zac67 stated the sender usually likes to know where the ICMP packet comes from, so it encapsulates it in an IP header, that IP header contains a field called 'protocol' when an ICMP packet is carried in the payload the protocol field is set[3] to 1 (0x01 in hex or 00000001 in binary), the protocol field is also bits (1 byte) long.
Below is some useful resources and sources.
Hope this helps.
https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
http://slideplayer.com/slide/3602717/
http://www.enterprisenetworkingplanet.com/netsp/article.php/3584166/Networking-101-Understanding-and-Using-ICMP.htm
http://www.pearsonitcertification.com/articles/article.aspx?p=1804873
[1] - http://www.keyboardbanger.com/wp-content/uploads/2015/07/ICMP-header.png
[2] - https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Control_messages
[3] - https://en.wikipedia.org/wiki/List_of_IP_protocol_numbers
answered Dec 9 at 21:09
Xuebit
1
answered Dec 9 at 21:09
Xuebit
1
answered Dec 9 at 21:09
Xuebit
1
answered Dec 9 at 21:09
Xuebit
1
1
2
The real definition of ICMP is RFC 792, Internet Control Message Protocol. An ICMP message can certainly be longer than eight total bytes. In fact, it will include the IP header (20 bytes for IPv4) and the first 64 bits (eight bytes) of the IP payload: "The internet header plus the first 64 bits of the original datagram's data." That is enough to include the source and destination addresses of protocols like TCP or UDP.
– Ron Maupin♦
Dec 9 at 21:17
add a comment |
2
The real definition of ICMP is RFC 792, Internet Control Message Protocol. An ICMP message can certainly be longer than eight total bytes. In fact, it will include the IP header (20 bytes for IPv4) and the first 64 bits (eight bytes) of the IP payload: "The internet header plus the first 64 bits of the original datagram's data." That is enough to include the source and destination addresses of protocols like TCP or UDP.
– Ron Maupin♦
Dec 9 at 21:17
2
2
The real definition of ICMP is RFC 792, Internet Control Message Protocol. An ICMP message can certainly be longer than eight total bytes. In fact, it will include the IP header (20 bytes for IPv4) and the first 64 bits (eight bytes) of the IP payload: "The internet header plus the first 64 bits of the original datagram's data." That is enough to include the source and destination addresses of protocols like TCP or UDP.
– Ron Maupin♦
Dec 9 at 21:17
The real definition of ICMP is RFC 792, Internet Control Message Protocol. An ICMP message can certainly be longer than eight total bytes. In fact, it will include the IP header (20 bytes for IPv4) and the first 64 bits (eight bytes) of the IP payload: "The internet header plus the first 64 bits of the original datagram's data." That is enough to include the source and destination addresses of protocols like TCP or UDP.
– Ron Maupin♦
Dec 9 at 21:17
add a comment |
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