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Wireshark-users: Re: [Wireshark-users] Capture filter question

From: Marco Zuppone <msz@xxxxxx>
Date: Sun, 6 Nov 2011 09:18:18 +0000
Hello David,

the point of my question was:
What is the difference between 'not arp and port not 53' and 'not arp and not port 53'??
Maybe is possible to reduce the problem to: what is the difference between 'not port xxx' and 'port not xxx' ?
Both the syntaxes are accepted but I was wondering if there is a difference in the end result if the 'not' clause is before or after the 'port' one.
 Thanks in advance & Regards,
Marco - StockTrader

On 6 Nov 2011, at 01:54, David Alanis wrote:

> Quoting David Alanis <canito@xxxxxxxx>:
> 
>> Quoting Marco Zuppone <msz@xxxxxx>:
>> 
>>> Hello,
>>> 
>>> I have a question about capture filters.
>>> I noticed that the basic capture filter predefined in Wireshark to   do not capture arp and DNS requests is defined in this way:
>>> not arp and port not 53
>>> 
>>> What is the difference with: not arp and not port 53?
>>> 
>>> Thanks in advance
>>> Marco - StockTrader
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>> 
> 
> Sorry, I think I jumped the gun on my previous e-mail. I know that 'not arp' will filter out the address resolution protocol. 'not port 53' will simply discard communication over port 53.
> 
> Is there something more specific that I am not understanding about these two capture filters?
> 
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