Wireshark-users: Re: [Wireshark-users] how can I filter on traffic that is (a) going in/out throu
From: Martin Visser <martinvisser99@xxxxxxxxx>
Date: Mon, 16 Aug 2010 13:08:23 +1000
Using hostnames in the capture filter will only work if your capturing PC has DNS connectivity and/or an entry in an hosts file. 

When you said it "does NOT do the job" is not capturing anything or capturing everything or something else? Unfortunately it is difficult to provide an answer without knowing what output you are seeing.

(If your proxy is a regular web proxy then your web traffic will almost definitely this address as the source or destination - this is the main function of the web proxy, to shield your client from the actual web servers).

Regards, Martin

MartinVisser99@xxxxxxxxx


On Mon, Aug 16, 2010 at 11:40 AM, Greg Hauptmann <greg.hauptmann.ruby@xxxxxxxxx> wrote:
still stuck on this :(

I've found that using for a capture filter "tcp and host <<PC IP
ADDRESS>> and host proxy.mycompany.com", whilst is a valid filter,
does NOT do the job I require.

It seems to be the case the actual traffic flow will reflect an IP
address that has a host name of one of the assigned proxy servers by
the main DNS server (e.g. proxy4.domainx.mycompany.com) and hence I'm
guessing due to this the filter does not work.

Any other ideas/suggestions here?

I'm kind of stuck for the moment. Again the challenge is how to
capture traffic only bound through the proxy servers, but for which
you don't really know which proxy server that DNS is going to allocate
to you based on the main DNS proxy name (proxy.mycompany.com).


On 15 August 2010 21:09, Greg Hauptmann <greg.hauptmann.ruby@xxxxxxxxx> wrote:
> in fact would a capture filter of "host proxy.mycompany.com and host
> <my local host ip>" be enough to solve this?  i.e. would wireshark
> then, irrespective of the actual proxy server my request gets assigned
> to (noting there are several nominated under the one DNS name for
> resiliency), just double check that the IP address for this proxy
> server resolves to "proxy.mycompany.com" and then if it does put it in
> scope?
>
>
> On 13 August 2010 15:08, Greg Hauptmann <greg.hauptmann.ruby@xxxxxxxxx> wrote:
>> Hi,
>>
>> Can anyone advise how I could set up a filter that covered off only
>> traffic that is
>>
>> (a) going in/out through the company internet proxy [e.g.
>> proxy.mycompany.com] - note here I want to be able to put the DNS name
>> for the proxy here [as there can be a number of different IP's that
>> DNS may issue back to give you your specific proxy server to use]
>>
>> (b) to/from my PC that is running wireshark?
>>
>>
>> thanks
>>
>
>
>
> --
> Greg
> http://blog.gregnet.org/
>



--
Greg
http://blog.gregnet.org/
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