Snort mailing list archives
RE: ICMP Destination Unreachable (Communication Administratively Prohibited)
From: "Dushyanth Harinath" <dushy () archeanit com>
Date: Sat, 25 Aug 2001 15:34:28 +0530 (IST)
Hi, Thanks for the reply.Iam in the process of going through ur site and "ICMP usage in scanning" whitepaper.Keep up the good work :D. Here is the complete trace from alerts log file. [**] [1:485:1] ICMP Destination Unreachable (Communication Administratively Prohibited) [**] 08/21-17:06:51.784780 157.130.91.86 -> 203.115.120.210 ICMP TTL:243 TOS:0x0 ID:51765 IpLen:20 DgmLen:56 Type:3 Code:13 DESTINATION UNREACHABLE: PACKET FILTERED ** ORIGINAL DATAGRAM DUMP: 203.115.120.210:1025 -> 63.80.0.50:53 UDP TTL:45 TOS:0x0 ID:52288 IpLen:20 DgmLen:79 Len: 59 ** END OF DUMP Thanks again, Best regards dushyanth
Dushyanth, The Error message indicates that the destination system is configured to reject datagrams from the sending system. This error is used when datagrams based on some sort of criteria are being filtered by a filtering device (firewall/router/other filtering devices) restrictions or other security measures. We can conclude that our Destination Host might be up and running, but we cannot reach it, since the filtering device is blocking our packets, and is instructing us to stop sending datagrams. With the next example a router is configured to block all requests, coming from the Internet, targeting port 53 on the destination machine it applies its ACL on: 05/09/01-12:29:41.399543 RoutersIP -> SourceIP ICMP TTL:244 TOS:0x0 ID:24442 IpLen:20 DgmLen:56 Type:3 Code:13 DESTINATION UNREACHABLE: PACKET FILTERED ** ORIGINAL DATAGRAM DUMP: SourceIP:4667 -> DestinationIP:53 TCP TTL:53 TOS:0x0 ID:40019 IpLen:20 DgmLen:60 **U****F Seq: 0x97EABAF6 Ack: 0x1C1D1E1F Win: 0x2223 TcpLen: 8 UrgPtr: 0x2627 ** END OF DUMP 00 00 00 00 45 00 00 3C 9C 53 40 00 35 06 29 B0 ....E..<.S@.5.). xx xx xx xx yy yy yy yy 12 3B 00 35 97 EA BA F6 .....Z...;.5.... For more information please see "ICMP Usage In Scanning" Chapter 2 page 20, 52-53. Available from http://www.sys-security.com/html/projects/icmp.html. Regarding your example, these systems report that communication from your system was not able to reach its destination because a filtering device blocked your packets. If you had put the complete trace we would be able to tell what communication exactly caused this error message to be trigger. -----Original Message----- From: snort-users-admin () lists sourceforge net [mailto:snort-users-admin () lists sourceforge net] On Behalf Of Dushyanth Harinath Sent: ù 25 àåâåñè 2001 9:19 To: snort-users () lists sourceforge net Subject: [Snort-users] ICMP Destination Unreachable (Communication Administratively Prohibited) Hi guys, Iam new to snort and have a little bit of networking knowledge. I have installed snort in my server with snortdb support aand i have also installed snortreport.Snort is working fine .I have this snort alert's from more that 10 source ip's targetting machine on my network.The exact message is. ICMP Destination Unreachable (Communication Administratively Prohibited) CID:1 [**] ICMP Destination Unreachable (Communication Administratively Prohibited) [**] 2001-08-21 17:06:51 157.130.91.86 -> 203.115.120.210 ICMP TTL:243 TOS:0x0 ID:51765 IPLen: DgmLen:56 HLen:5 CSumIP:0xC070 Type:3 Code:13 ID: Seq: This is just one such alert .I have got 12 alerts from different ip's in the last 12 hrs and above 48 in the last 30 days. I know i can disable this alert by commenting out the line in icmp.rules.But iam not sure what this means. I will be glad to RTFM or will someone please enlighten me about this. Best regards dushyanth
-- My computer, my documents, my briefcase, my A??! Dushyanth Harinath Programmer/Sys Admin Archean Infotech Limited Ph No:091-040-3228666,6570704,3228674 http://www.archeanit.com ----------------------------------------- This email was sent using SquirrelMail. "Webmail for nuts!" http://squirrelmail.org/ _______________________________________________ Snort-users mailing list Snort-users () lists sourceforge net Go to this URL to change user options or unsubscribe: http://lists.sourceforge.net/lists/listinfo/snort-users Snort-users list archive: http://www.geocrawler.com/redir-sf.php3?list=snort-users
Current thread:
- ICMP Destination Unreachable (Communication Administratively Prohibited) Dushyanth Harinath (Aug 25)
- RE: ICMP Destination Unreachable (Communication Administratively Prohibited) Ofir Arkin (Aug 25)
- RE: ICMP Destination Unreachable (Communication Administratively Prohibited) Dushyanth Harinath (Aug 25)
- RE: ICMP Destination Unreachable (Communication Administratively Prohibited) Ofir Arkin (Aug 25)
- RE: ICMP Destination Unreachable (Communication Administratively Prohibited) Dushyanth Harinath (Aug 25)
- RE: ICMP Destination Unreachable (Communication Administratively Prohibited) Ofir Arkin (Aug 25)