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What would be the correct way of…?

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Making a capture filter(I think) that hides packets from 10.1.1.2, only udp and less then 75 length. I'm really knew so please help. Edit: new* hahahah

asked 02 Sep '14, 20:26

akiyopringle's gravatar image

akiyopringle
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edited 02 Sep '14, 20:26

2

I.e.:

  • you don't want to see packets from 10.1.1.2;
  • you only want to see UDP packets (i.e., you don't want to see non-UDP packets);
  • you only want to see packets less than 75 bytes long?

If so, by "length" do you mean the length of the full link-layer packet, including the link-level header (Ethernet header, 802.11 header, etc.), or do you mean the length of the IP packet (not including the length of the link-level header but including the length of the IP header), or the length of the UDP packet (not including the length of the link-level and IP headers but including the length of the UDP header), or the length of the UDP payload (not including the length of the link-level, IP, and UDP headers)?

(04 Sep '14, 02:33) Guy Harris ♦♦

I don't know man. I can't understand half of what you're saying :(

(07 Sep '14, 01:01) akiyopringle

One Answer:

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So I'll ignore the length part, as I can't answer that without knowing exactly what you mean by "less than 75 length".

If by "capture filter" you mean you want to capture live traffic and discard all the traffic in which you're not interested, the filter would be

not host 10.1.1.2 and udp

If you have already captured some traffic, and want to display only the packets that aren't from 10.1.1.2 and that are UDP packets, that would be a display filter, and the display filter would be

!(ip.addr == 10.1.1.2) and udp

answered 07 Sep '14, 01:27

Guy%20Harris's gravatar image

Guy Harris ♦♦
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accept rate: 19%