[CentOS] Spotty internet connection

[Matt Garman]

On Thu, Feb 2, 2017 at 7:13 PM, TE Dukes <tdukes at palmettoshopper.com> wrote:
> Lately I have been getting slow  and partial page loads, server not found,
> server timed out, etc.. Get knocked off ssh when accessing my home server
> from work, etc. Its not the work connection because I don't have problems
> accessing other sites, just here at home and my home server.
>
> Is there any kind of utility to check for failing hardware?

I have the exact same problems from time to time via Comcast.  Mine
comes and goes, and lately it hasn't been too bad.  But when it comes,
it's down for very small amounts of time, maybe 30-90 seconds, which
is just long enough to be annoying, and make the service unusable.

When it was really bad (intermittent dropouts as described above,
almost every night during prime time, usually for several hours at a
time) I wrote a program to do constant pings to several servers at
once.  If you're interested, I'll see if I can find that script.  But,
conceptually, it ran concurrent pings to several sites, and kept some
stats on drops longer than some threshold.  Some tips on a program
like this: use IP addresses, rather than hostnames, because ultimately
using a hostname implicitly does a DNS lookup, which likely requires
Internet service to work.  I also did several servers at once, so I
could prove it wasn't just the one site I was pinging.  Included in
the list of servers was also the nexthop device beyond my house
(presumably Comcast's own router).  Use traceroute to figure out
network paths.

After running this for a while---before I called them with the
evidence---the problem magically cleared up, and since then it's been
infrequent enough that I haven't felt the need to fire up the script
again.  When it comes to residential Internet, I am quite cynical
towards monopoly ISPs like Comcast... so maybe they saw the constant
pings and knew I was building a solid case and fixed the problem.  Or
maybe enough people in my area complained of similar problems and they
actually felt uncharacteristically caring for a second.

I haven't been there in a while, but in the past, I've gotten a lot of
utility out of the DSLReports Forums[1].  There are private forums
that will put you in direct contact with technical people at your ISP.
It can sometimes be a good way to side-step the general customer
service hotline and get in touch with an actual engineer rather than a
script reader.  Maybe not, but worst-case you're only out some time.
Also, you might post this same question to one of the public forums
over there, as there seems to be lots of knowledgeable/helpful people
hanging out there.  (Despite the name, it's not only about DSL, but
consumer ISPs in general.)

[1] http://www.dslreports.com/forums/all

Good luck, let us know if you come up with any decent resolution!