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non-piggy-backed ACK with total IP length = 52
From: Andrej van der Zee <andrejvanderzee () gmail com>
Date: Sun, 27 Feb 2011 13:46:34 +0900
Hi, I am looking at a ACK-packet with total IP length of 52. Normally I find non-piggy-backed ACKs only 40 bytes. In this case the ACK comes after a retransmission. The extra 12 bytes are contained in the TCP options. In Wireshark, it sais: Options (12 bytes) NOP NOP SACK: 553-1130 left edge: 533 (relative) right edge: 1130 (relative) It seems like it tries to indicate which of the duplicate packet it actually acknowledges by explicitly stating the byte range, in case the retransmitted packet is longer than the original packet because more send-data became available before the retransmission. Is my understand correct? What is actually contained in these extra 12 bytes? What does NOP mean? Thank you, Andrej ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org?subject=unsubscribe
Current thread:
- non-piggy-backed ACK with total IP length = 52 Andrej van der Zee (Feb 26)
- Re: non-piggy-backed ACK with total IP length = 52 Guy Harris (Feb 26)
- Re: non-piggy-backed ACK with total IP length = 52 Andrej van der Zee (Feb 27)
- Re: non-piggy-backed ACK with total IP length = 52 Andrej van der Zee (Feb 27)
- Re: non-piggy-backed ACK with total IP length = 52 Sake Blok (Feb 27)
- Re: non-piggy-backed ACK with total IP length = 52 Andrej van der Zee (Feb 27)
- Re: non-piggy-backed ACK with total IP length = 52 Andrej van der Zee (Feb 27)
- Re: non-piggy-backed ACK with total IP length = 52 Guy Harris (Feb 26)