UDP 137 to any broadcast address is an old (but still sorta functional) name resolution method; the neighborhood equivalent of me screaming "what's Gregor's address?" down your street. Since ISA identifies the packet as "malformed", it means that the source of the packet is sending incorrect in the packet header. How many clients are doing this? Jim Harrison MCP(NT4, W2K), A+, Network+, PCG http://isaserver.org/pages/author_index.asp?aut=3 http://isatools.org Read the help / books / articles! ----- Original Message ----- From: "Gregor Streng" <gregorstreng@xxxxxxxxxxxx> To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> Sent: Thursday, November 21, 2002 3:27 AM Subject: [isalist] ISA UDP 137 http://www.ISAserver.org Hello, I've got a problem. The ISA Controls Service on the ISA stops after a few, aprox. 15, packet filtering errors. The errors is: Packet filter protocol violation. For more information about this event, see ISA Server Help. EventID: 14046 The logfile shows this line: 2002-11-21 10:52:01 10.0.0.x 10.255.255.255 Udp 137 137 - Malformed - 45 00 00 4e 74 73 00 00 80 11 b0 f9 0a 00 00 34 0a ff ff ff 00 89 00 89 00 3a 0c 3f 81 82 01 10 00 01 00 00 00 00 00 00 20 45 48 46 43 45 46 45 48 45 50 46 43 43 41 43 41 43 41 43 41 43 41 43 41 43 41 43 41 43 41 43 41 00 00 20 00 01 Has anyone an idea why clients suddenly start to send netbois (if I'm right Udp 137 is one) requests to 10.255.255.255. The problem is not only clients are causing this also servers,the DC, the webserver, the exchange .. Moreover there is no box that has got this ip assigned. Any help would be highly appreciated. Gregor ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=isalist ISA Server Newsletter: http://www.isaserver.org/pages/newsletter.asp ISA Server FAQ: http://www.isaserver.org/pages/larticle.asp?type=FAQ ------------------------------------------------------ Exchange Server Resource Site: http://www.msexchange.org/ Windows Security Resource Site: http://www.windowsecurity.com/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jim@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub')