UDP Port Scan

Unanswered Question
May 4th, 2010

I keep getting the following message in my logs and I am trying to find out

how I can resolve this. Thanks in advance for all of your help.

- No UDP Server to service request

- request discarded to service: 137

- source machine -

- destination machine -

source port = 137

destination port = 137

This is taking place on the inside interface.

I have this problem too.
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Federico Coto F... Tue, 05/04/2010 - 07:59


Find out why the source machine is sending NetBIOS traffic in your LAN.

NetBIOS uses broadcast communication on those ports.


astripat Tue, 05/04/2010 - 08:02


I hope you are getting the following syslog:


Error Message    %PIX|ASA-7-710005: {TCP|UDP} request discarded from 
source_address/source_port to interface_name:dest_address/service

Explanation   This message appears when the security appliance does not have a UDP server that services the UDP request. The message can also indicate a TCP packet that does not belong to any session on the security appliance. In addition, this message appears (with the service snmp) when the security appliance receives an SNMP request with an empty payload, even if it is from an authorized host. When the service is snmp, this message occurs a maximum of 1 time every 10 seconds so that the log receiver is not overwhelmed.

The decription can be found here:


when exatly you get this syslog?




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