nanog mailing list archives
Re: Short-circuited traceroutes on FIOS
From: Rob Foehl <rwf () loonybin net>
Date: Tue, 10 Dec 2019 23:48:48 -0500 (EST)
On Tue, 10 Dec 2019, Joe Maimon wrote:
Anyone have an idea why there are some destinations that on residential verizon fios here in NY area terminate right on first external hop?
They're returning fake ICMP echo replies from their BNGs for echo packets with TTL=1, thus any ICMP traceroute (Windows and mtr by default, etc.) seems to terminate at their layer 3 edge. UDP/TCP traceroute are unaffected, ICMP works fine if you set the initial TTL to n+1 where n is the hop that's lying.
Support claims that it was a mistake, but it's also been 15+ months and it's pretty deliberate behavior. Draw your own conclusions...
-Rob
Current thread:
- Re: Short-circuited traceroutes on FIOS, (continued)
- Re: Short-circuited traceroutes on FIOS Christopher Morrow (Dec 10)
- Re: Short-circuited traceroutes on FIOS Nimrod Levy (Dec 11)
- Re: Short-circuited traceroutes on FIOS Javier J (Dec 11)
- Re: Short-circuited traceroutes on FIOS Peter Beckman (Dec 12)
- Re: Short-circuited traceroutes on FIOS Javier J (Dec 13)
- Re: Short-circuited traceroutes on FIOS Warren Kumari (Dec 13)
- Re: Short-circuited traceroutes on FIOS Stephen Frost (Dec 11)
- Re: Short-circuited traceroutes on FIOS Saku Ytti (Dec 11)
- Re: Short-circuited traceroutes on FIOS Valdis Klētnieks (Dec 11)
- Re: Short-circuited traceroutes on FIOS Etienne-Victor Depasquale (Dec 11)
- RE: Short-circuited traceroutes on FIOS Aaron Gould (Dec 12)
- Re: Short-circuited traceroutes on FIOS Javier J (Dec 12)