RE: anyone use fbtracert successfully?

[Adam Thompson <athompson () merlin mb ca>]

Thank you!!  Some of those tools are proving much more useful for me than fbtracert.  (In particular, traceflow has 
been updated recently enough that it “just works” in common environments that have Python3.  And while it may not be 
perfect, it’s good enough to show what I need.)
-Adam
(who apparently has lost the skills needed to Google usefully, in his decrepitude)

Adam Thompson
Consultant, Infrastructure Services
[1593169877849]
100 - 135 Innovation Drive
Winnipeg, MB, R3T 6A8
(204) 977-6824 or 1-800-430-6404 (MB only)
athompson () merlin mb ca<mailto:athompson () merlin mb ca>
www.merlin.mb.ca<http://www.merlin.mb.ca/>

From: Hugo Slabbert <hugo () slabnet com>
Sent: Thursday, November 25, 2021 10:39 AM
To: Thomas Scott <mr.thomas.scott () gmail com>
Cc: Adam Thompson <athompson () merlin mb ca>; nanog <nanog () nanog org>
Subject: Re: anyone use fbtracert successfully?

What about some other options?

https://paris-traceroute.net/
https://dublin-traceroute.net/
https://github.com/rucarrol/traceflow

--
Hugo Slabbert


On Wed, Nov 24, 2021 at 9:54 AM Thomas Scott <mr.thomas.scott () gmail com<mailto:mr.thomas.scott () gmail com>> wrote:
Ha, my apologies, I thought I was writing this for a Linux User Group, not a NOG. Ignore my simplistic explanations.
- Thomas Scott | mr.thomas.scott () gmail com<mailto:mr.thomas.scott () gmail com>


On Wed, Nov 24, 2021 at 12:47 PM Thomas Scott <mr.thomas.scott () gmail com<mailto:mr.thomas.scott () gmail com>> wrote:
I have used it successfully in a test environment that I was using ECMP in. Most of the public networks that I've 
worked with don't use ECMP as often as other methods for steering traffic (LAGs, BGP MEDs, etc).

What I have seen it fantastically useful for was troubleshooting a transit provider, or for when they were congested or 
had a flapping core link. Granted I think it's still subject to ICMP deprioritization (most SP's use it prodigiously), 
and most MPLS cores don't decrement TTL, but it was still useful to be able to show them "no, at this IP, I always drop 
traffic, when..."

- Thomas Scott | mr.thomas.scott () gmail com<mailto:mr.thomas.scott () gmail com>


On Wed, Nov 24, 2021 at 12:23 PM Adam Thompson <athompson () merlin mb ca<mailto:athompson () merlin mb ca>> wrote:
The tool fbtracert (http://github.com/facebookarchive/fbtracert) was mentioned here recently as a way to get visibility 
into multi-pathing.
Has anyone here ever used this tool successfully?

Supposedly Facebook uses this tool internally, but… that doesn’t help much.

I’ve tried it on 4 different platforms/OSes (WSL Ubuntu; RedHat; Debian; OpenBSD), and versions of Go (v1.10 through 
v1.16), in three very different environments (on-prem public IP; on-prem NAT’d; cloud public IP), and I’ve yet to see 
it produce any meaningful output – each run/iteration/thread only detects one, single, hop out of the entire chain of 
routers, making it less than useful.  Granted, that’s not a full regression test by any means, but if anyone here has 
ever used it successfully, could you please let me know what sort of environment you ran it in/on?

Thanks,
-Adam

Adam Thompson
Consultant, Infrastructure Services

100 - 135 Innovation Drive
Winnipeg, MB, R3T 6A8
(204) 977-6824 or 1-800-430-6404 (MB only)
athompson () merlin mb ca<mailto:athompson () merlin mb ca>
www.merlin.mb.ca<http://www.merlin.mb.ca/>