Writing a Simple Java udp portscanner

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robert - 22 May 2006 17:56 GMT

Hi all,

I need to find all the machines on a subnet that have a particular UDP
port open - a snmp program using UDP, not TCP, off of port 8001 but I
suppose that may not matter.

I've seen some full projects but really I'm looking for a simple class
or open source API. I found this one, though a bit dated - need to
check if it can do UDP:

http://groups.google.com.br/group/sac.general/browse_frm/thread/25246ed18c418f48
/717d23edddbb2b38?hl=pt-BR&lr=&ie=UTF-8&oe=UTF-8&rnum=26&prev=/groups%3Fq%3Dport
%2Bscan%2Bjava%26hl%3Dpt-BR%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26start%3D20%26sa%
3DN#717d23edddbb2b38

Any ideas?
Robert

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steve - 22 May 2006 22:21 GMT

groups%3Fq%3Dport%2Bscan%2Bjava%26hl%3Dpt-BR%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-
8

> %26start%3D20%26sa%3DN#717d23edddbb2b38

dreadful code

it should be threaded, not scan a host in a loop.

also it needs some stealth code, as any firewall would pick up it's attempt
to port scan.

Steve

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EJP - 23 May 2006 01:10 GMT

> Hi all,
>
[quoted text clipped - 5 lines]
> or open source API. I found this one, though a bit dated - need to
> check if it can do UDP:

It can't, and it's a pretty poor attempt anyway. Also it scans all TCP
ports on a single host, the opposite of what you want to do.

Do you know the application protocol that is used on the port? If not,
you can't necessarily do this task *at all*, as you will have to provoke
each UDP server into sending you a reply somehow (there being no UDP
connect protocol).

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Writing a Simple Java udp portscanner

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