Security Basics mailing list archives
Re: Removing ping/icmp from a network
From: Ansgar -59cobalt- Wiechers <bugtraq () planetcobalt net>
Date: Tue, 1 Apr 2008 14:13:39 +0200
On 2008-03-29 Michael Painter wrote:
On Friday, March 28, 2008 6:44 AM Ansgar -59cobalt- Wiechers wrote:On 2008-03-27 Michael Painter wrote:I'm not sure what 'clean' means, but I'm not supposed to see 10/8 addresses on the "Internet".You aren't seeing them "on the Internet".Poor choice of words, maybe? How about via the Internet? Anyway, there are (at least) two schools of thought on this, as shown by this thread from NANOG. http://www.cctec.com/maillists/nanog/historical/0102/threads.html#00702
[...]
(From RFC 1918) Because private addresses have no global meaning, routing information about private networks shall not be propagated on inter-enterprise links, and packets with private source or destination addresses should not be forwarded across such links. Routers in networks not using private address space, especially those of Internet service providers, are expected to be configured to reject (filter out) routing information about private networks.
Traceroute results don't qualify as routing information (that would be BGP, OSPF, or RIP data), and the private addresses only shows up as the source address of the "time exceeded" packet. You'll note that the RFC doesn't require, but only recommends not forwarding packets with private source addresses, so there's no real violation of RFC 1918 here. I'll agree that it is a bad practice, though. Regards Ansgar Wiechers -- "All vulnerabilities deserve a public fear period prior to patches becoming available." --Jason Coombs on Bugtraq
Current thread:
- Re: Removing ping/icmp from a network Jason (Apr 01)
- Re: Removing ping/icmp from a network Ansgar -59cobalt- Wiechers (Apr 04)
- Re: Removing ping/icmp from a network Jason (Apr 07)
- Re: Removing ping/icmp from a network Ansgar -59cobalt- Wiechers (Apr 07)
- Re: Removing ping/icmp from a network Jason (Apr 07)
- Re: Removing ping/icmp from a network Jason (Apr 07)
- Re: Removing ping/icmp from a network Mark Owen (Apr 07)
- Re: Removing ping/icmp from a network Jason (Apr 07)
- Re: Removing ping/icmp from a network Ansgar -59cobalt- Wiechers (Apr 04)
- <Possible follow-ups>
- Re: Removing ping/icmp from a network Ansgar -59cobalt- Wiechers (Apr 01)
- Re: Removing ping/icmp from a network Mike Preston - Technomonk Industries (Apr 01)
- Re: Removing ping/icmp from a network Ansgar -59cobalt- Wiechers (Apr 01)
- Re: Removing ping/icmp from a network krymson (Apr 02)