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Why am i seeing so many Of these Zero Window flags?

0

I'm not seeing any reason why i should be getting these? The Application i am using to grab data from an sql server seems sluggish at times and during initialization seems to freeze. At the times where this latency happens i see alot of Window Update and Zero Window flags.

https://www.cloudshark.org/captures/b68f6cd0086b

It's difficult for me to confirm whether or not the issue starts with my server or my client?

asked 03 Jun '16, 16:36

Juxtapositioned0110's gravatar image

Juxtapositio...
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accept rate: 0%

The capture you've posted only shows one direction (the ACKs from the client to the server), and it is really not easy to find out what is going on from such a short capture and one direction. As the session establishment phase is missing, it is unclear even how big the window actually is, because the windows scaling factor information is missing. So the "256" may be 256 bytes or 65536 bytes or even more.

So please start capturing before starting the application and capture both directions. Then, if you have privacy concerns, use Tracewrangler to wipe out the payload and keep only the TCP overhead information, and post that modified capture (or post it as-is to exclude one possible source of errors if you don't).

(04 Jun '16, 00:58) sindy

One Answer:

1

Hi, problem is from 192.168.1.71 i.e client.... Receive buffer is getting exhausted....

Mostly bellow said solutions may solve the problem 1) While sending the data enable PUSH flag in TCP .... 2) Enable nagle's algorithm for more info https://en.wikipedia.org/wiki/Nagle's_algorithm

answered 03 Jun '16, 20:07

srinu_bel's gravatar image

srinu_bel
20151620
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