topic PIX DoS? in Network Security https://community.cisco.com/t5/network-security/pix-dos/m-p/85397#M711047 <P>I'm new to these firewalls so I'm not sure if this is a hack or something else. Every once in a while I get the following logged to my syslog server:</P><P></P><P> %PIX-4-500004: Invalid transport field for protocol=17, from 213.217.176.56/1599 to 255.255.255.255/0</P><P></P><P>Right after this happens my PIX is unable to reach my url filter (websense). Everytime. What's going on and how can I prevent it?</P><P></P><P>Thanks for any help.</P> Fri, 21 Feb 2020 06:01:00 GMT rgonzaga 2020-02-21T06:01:00Z PIX DoS? https://community.cisco.com/t5/network-security/pix-dos/m-p/85397#M711047 <P>I'm new to these firewalls so I'm not sure if this is a hack or something else. Every once in a while I get the following logged to my syslog server:</P><P></P><P> %PIX-4-500004: Invalid transport field for protocol=17, from 213.217.176.56/1599 to 255.255.255.255/0</P><P></P><P>Right after this happens my PIX is unable to reach my url filter (websense). Everytime. What's going on and how can I prevent it?</P><P></P><P>Thanks for any help.</P> Fri, 21 Feb 2020 06:01:00 GMT https://community.cisco.com/t5/network-security/pix-dos/m-p/85397#M711047 rgonzaga 2020-02-21T06:01:00Z Re: PIX DoS? https://community.cisco.com/t5/network-security/pix-dos/m-p/85398#M711055 <HTML><HEAD></HEAD><BODY><P>This message indicates that the source: 213.217.176.56 is sending a UDP packet with a destination port of 0. In your case it also has a broadcast address for the Destination. This should not have any impact on the PIX being unable to reach Websense.</P><P></P><P>Sincerely,</P><P></P><P>David.</P><P></P></BODY></HTML> Mon, 01 Apr 2002 17:06:04 GMT https://community.cisco.com/t5/network-security/pix-dos/m-p/85398#M711055 David White 2002-04-01T17:06:04Z