capturing dns packets using java

I want to log the websites visited in a system. So i decided to record the packets send by the system. I am using Jpcap API. I am able to record a lot of packets. Now what i want to do is i want to filter only DNS packets. I think that 开发者_StackOverflowwill be able to log the websites.

I want a way to filter the DNS packets. How can I do it?

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One uglier approach is to scan on port 53 for UDP. However, previous answer looks cleaner from implementation aspect.

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Here it says

You can check the following homepage for more details about filter expression. Designing Capture Filters for Ethereal/Wireshark

Thus, I believe

captor.setFilter("dns", true);

should work

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i found it easy processing all the packets in port 53 and so i used this filter

udp dst port 53

tanx jack for ur hint