How many bytes is ICMP?

An ICMP packet consists of an 8-byte ICMP header followed by the ICMP packet data, all encapsulated within an IP datagram. This parameter specifies the size of the ICMP packet data. A value of 0 results in an IP packet size of 64 bytes.

What is the content of 32 bytes for ping in ICMP protocol?

This option sets the number of ICMP Echo Requests to send, from 1 to 4294967295. The ping command will send 4 by default if -n isn’t used. Use this option to set the size, in bytes, of the echo request packet from 32 to 65,527. The ping command will send a 32-byte echo request if you don’t use the -l option.

What is the size of ICMP type?

All ICMP packets have an 8-byte header and variable-sized data section. The first 4 bytes of the header have fixed format, while the last 4 bytes depend on the type/code of that ICMP packet.

What is ICMP payload size?

As we have discussed above default size of ICMP payload is 32 bytes and the maximum is 1472 if the size of the payload packet is greater than 1472 then packet gets fragmented into small packets.

What determines the type of an ICMP packet?

The type determines what the ICMP packet is used for. Depending on the type, the 8-bit code field may also be used, which contains additional information. If the type does not have any codes defined, the code field is set to zero. For more general information on ICMP, see ICMP for IPv4.

How many bytes in a ping packet?

which would be 20 bytes of IP header, 8 bytes of ICMP header + 32 data, 18 bytes of min ethernet frame. In my case i did ping of win xp, 32 bytes of data. So, adding up, 20+8+32+18=78 bytes. But the sniffed packet says 74 bytes total frame on wire.

How many bytes are there in a frame packet?

But the sniffed packet says 74 bytes total frame on wire. After some research, i found that ethernet frame is taken as 6 byte D.A+6 byte S.A+ 2 byte type = 14 bytes. And there is no CRC byte added. With this, the frame packet will be 74 bytes exactly.

What is the ICMP header for echo packets?

An echo packet has type 8 set in the ICMP header, and the reply uses type zero. Neither have any codes defined, so the code field in the header is always set to zero. The second four bytes of the header includes two 16-bit fields; The Identifier and the Sequence. These are used to match a particular echo with the echo-reply.