nanog mailing list archives
Re: Vonage complains about VoIP-blocking
From: Daniel Golding <dgolding () burtongroup com>
Date: Tue, 15 Feb 2005 16:49:28 -0500
I've gotten a couple emails on this. To summarize: 1) some malware uses tftp. However much malware now uses other ports, such as 80 2) There are numerous buffer overflow bugs with tftp. This would seem to be better resolved with rACLs or ACLs towards loopback/interface blocks. (and, of course, turning tftp off and using scp or sftp) It would be interesting to find out what percentage of Internet accessible routers are remotely upgradable via TFTP presently. Sadly, this would be non-zero... - Dan On 2/15/05 4:28 PM, "Rob Thomas" <robt () cymru com> wrote:
Hi, Dan. ] Why block TFTP at your borders? To keep people from loading new versions of ] IOS on your routers? ;) Funny you should mention that. :) We have seen miscreants do exactly that. They will upgrade or downgrade routers to support a feature set of their choosing. A lot of malware uses TFTP to update itself as well. Please note that I am NOT advocating the blocking of TFTP. Thanks, Rob.
Current thread:
- Re: Vonage complains about VoIP-blocking, (continued)
- Re: Vonage complains about VoIP-blocking John Fraizer (Feb 15)
- Message not available
- Re: Vonage complains about VoIP-blocking John Fraizer (Feb 15)
- Re: Vonage complains about VoIP-blocking Majdi Abbas (Feb 15)
- Re: Vonage complains about VoIP-blocking Jared Mauch (Feb 15)
- Re: Vonage complains about VoIP-blocking Daniel Golding (Feb 15)
- Re: Vonage complains about VoIP-blocking Eric Gauthier (Feb 15)
- Re: Vonage complains about VoIP-blocking Thor Lancelot Simon (Feb 15)
- Re: Vonage complains about VoIP-blocking Adi Linden (Feb 15)
- Re: Vonage complains about VoIP-blocking Daniel Golding (Feb 15)
- Re: Vonage complains about VoIP-blocking Rob Thomas (Feb 15)
- Re: Vonage complains about VoIP-blocking Daniel Golding (Feb 15)
- Re: Vonage complains about VoIP-blocking Jon Lewis (Feb 16)
- Re: Vonage complains about VoIP-blocking John Kristoff (Feb 15)
- Re: Vonage complains about VoIP-blocking Eric Gauthier (Feb 15)
- RE: Vonage complains about VoIP-blocking Jay Hennigan (Feb 15)
- RE: Vonage complains about VoIP-blocking Nathan Allen Stratton (Feb 15)
- RE: Vonage complains about VoIP-blocking Michael Hallgren (Feb 15)