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looking for hostname router identifier validation


To support Internet topology analysis efforts, I have been working on
an algorithm to automatically detect router names inside hostnames
(PTR records) for router interfaces, and build regular expressions
(regexes) to extract them.  By "router name" inside the hostname, I
mean a substring, or set of non-contiguous substrings, that is common
among interfaces on a router.  For example, suppose we had the
following three routers in the savvis.net domain suffix, each with two




We might infer the router names are das1|nj2, das1|oc2, and das2|nj2,
respectively, and captured by the regex:

After much refinement based on smaller sets of ground truth, I'm
asking for broader feedback from operators.  I've placed a webpage at
https://www.caida.org/~mjl/rnc/ that shows the inferences my algorithm
made for 2523 domains.  If you operate one of the domains in that
list, I would appreciate it if you could comment (private is probably
better but public is fine with me) on whether the regex my algorithm
inferred represents your naming intent.  In the first instance, I am
most interested in feedback for the suffix / date combinations for
suffixes that are colored green, i.e. appear to be reasonable.

Each suffix / date combination links to a page that contains the
naming convention and corresponding inferences.  The colored part of
each hostname is the inferred router name.  The green hostnames appear
to be correct, at least as far as the algorithm determined.  Some
suffixes have errors due to either stale hostnames or incorrect
training data, and those hostnames are colored red or orange.

If anyone is interested in sets of hostnames the algorithm may have
inferred as 'stale' for their network, because for some operators it
was an oversight and they were grateful to learn about it, I can
provide that information.


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