Messages in this thread | | | From | CaT <> | Subject | Re: PPP bug | Date | Mon, 8 Feb 1999 15:25:41 +1100 (EST) |
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Andrew Snare wrote the following: > > --pgp-sign-Multipart_Mon_Feb__8_15:11:52_1999-1 > Content-Type: text/plain; charset=US-ASCII > > >>>>> "Dick" == Richard B Johnson <root@chaos.analogic.com> writes: > > Dick> The +++ sequence in a packet can't affect the modem because > Dick> you need at least 500ms (lowest you can set it) of quiet after > Dick> the sequence to change its mode. The data strings will never > Dick> be the last thing sent, so you can't get 500ms between > Dick> characters no matter how hard you try. > > This is partially true. Unfortunately (I believe) Hayes patented the > idea of there having to be a pause before and after the +++ sequence, > and some manufacturers (namely Rockwell) simply look for any +++ > sequence as a break sequence regardless of timing. Experience is that > roughly 40% of people on IRC are susceptible to this problem, so these > modems are fairly wide-spread. To test a host (with permission, > of-course:) use: > > % ping -p 2b2b2b415448300d <hostname>
*laughs and laughs*
501.damien@kinder:/home/damien>> ping -p 2b2b2b415448300d axe PATTERN: 0x2b2b2b415448300d PING axe (203.35.182.2): 56 data bytes ping: sendto: Network is unreachable ping: wrote axe 64 chars, ret=-1 ping: sendto: Network is unreachable ping: wrote axe 64 chars, ret=-1 ping: sendto: Network is unreachable ping: wrote axe 64 chars, ret=-1 ping: sendto: Network is unreachable ping: wrote axe 64 chars, ret=-1 ping: sendto: Network is unreachable ping: wrote axe 64 chars, ret=-1 ping: sendto: Network is unreachable ping: wrote axe 64 chars, ret=-1
--- axe ping statistics --- 7 packets transmitted, 0 packets received, 100% packet loss
Boom! :) Ahh well. This -IS- a cheaparse modem afterall :)
Also figures that BSD compression on my ppp link should've died sometime before that. :/
> If it replies, the host is fine. If it doesn't, it's got a faulty > modem. This was all covered in depth a while back on the Bugtraq > mailing lists (search the geek-girl archives... I think "Old school > DoS" was the subject). The only solution if you've got one of these > modems is to change break character from + to something else, or > (preferably) disable it entirely with AT S2=255. An interesting > side-effect of the bug is that you can "patch" people's modems for > them if they're buggy with something like (untested): > > % ping -p 2b2b2b415453323d323535204f300d
Don't have time to do the ascii on this one... This does the S2 command?
-- CaT (cat@zip.net.au) URL: http://www.zip.com.au/dev/null
There was farting in the air that night, It lit so bright, Fernando...
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