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Groups > comp.os.linux.networking > #3884
| From | Moe Trin <ibuprofin@painkiller.example.tld.invalid> |
|---|---|
| Newsgroups | comp.os.linux.networking |
| Subject | Re: What should I change my DNS to? (combined response) |
| Date | 2016-09-08 19:34 +0000 |
| Organization | Heisenberg slept here, or somewhere else nearby. |
| Message-ID | <slrnnt3f9m.sv0.ibuprofin@planck.phx.az.us> (permalink) |
| References | (2 earlier) <nqlos1$1rug$1@gioia.aioe.org> <nqlr21$7qp$1@dont-email.me> <nqlslb$2ct$1@gioia.aioe.org> <slrnnsudm2.aik.ibuprofin@planck.phx.az.us> <nqql5c$1h76$1@gioia.aioe.org> |
On Thu, 8 Sep 2016, in the Usenet newsgroup comp.os.linux.networking, in article
<nqql5c$1h76$1@gioia.aioe.org>, F Volker wrote:
>Hindsight is a beautiful thing :)
Absolutely!
>My router has indeed a reset button which if pressed for about 10
>seconds or so will activate a complete reset to its original (as
>purchased) state.
Provided that when this is done, "things work properly", this is a
useful feature. One must then remember to put in your personal
settings, such as changing that "admin:admin" password ;-)
>It would have been most revealing if I had the mindset resetting the
>router before initiating contacted with my ISP... maybe we wouldn't
>have this particular conversation. But rest assured I'll remember if
>this 'challenge' recurs.
Your system probably has "ping" installed.
[dawn ~]$ which ping
ping is /bin/ping
[dawn ~]$ whatis ping
ping (8) - send ICMP ECHO_REQUEST to network hosts
[dawn ~]$
A problem is finding a host out on the Internet that will respond (ping
has been abused so much that many Internet hosts disable the responder).
Lessee, www.ibiblio.org is a host in the Eastern USA, and it has an IP
address of 152.19.134.40. I choose it because from experience I know it
will _usually_ respond to pings.
[dawn ~]$ ping -c1 152.19.134.40
PING 152.19.134.40 (152.19.134.40) 56(84) bytes of data.
64 bytes from 152.19.134.40: icmp_req=1 ttl=48 time=126 ms
That shows I have a working connection to at least some part of the
world. Next,
[dawn ~]$ ping -c1 www.ibiblio.org
PING www.ibiblio.org (152.19.134.40) 56(84) bytes of data.
64 bytes from www.ibiblio.org (152.19.134.40): icmp_req=1 ttl=48
time=436 ms
This shows that my DNS can discover the IP address of that host. If
the first step fails, you don't have connectivity. If it works, but
the second step (by name) fails, something is wrong with the DNS or
DNS setup. Note the "extra time" that the second test took - that's
mostly the time needed for the DNS server to figure out the name/IP
translation. It helps to know the hostname and IP address of several
systems "out there" that will respond to pings. Two other hosts are
"google-public-dns-a.google.com (8.8.8.8) and it's brother
"google-public-dns-b.google.com" at 8.8.4.4.
If you are curious, there are two other tools that MAY be installed on
your system - traceroute and/or tcptraceroute. Both use a trick with
the IP header "Time-To-Live" parameter, and depend on hosts along the
path responding with a "you didn't throw the ball far enough" message.
This will allow you to discover where out on the Internet the connection
is failing. See the man page for "traceroute" for examples and a better
explanation. Still another tool is tracepath, though I find it is more
dependent on the external systems "following the rules".
Ping will "fail" if the destination host is down, or doesn't want to
respond. Traceroute is less dependent on the destination, but some
relay points along the route may drop the error message (ICMP type 11
code 0 - "time-to-live equals 0 during transit") that traceroute uses
to identify the intermediate hops. The programs are similar, but
complimentary - one may work while the other may not. I prefer the
"tcptraceroute" program (equivalent to "traceroute -T" in a Debian based
distro) because it has a slightly better chance of working than basic
"traceroute".
Old guy
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What should I change my DNS to? F Volker <here@home.net> - 2016-09-06 06:32 +0700
Re: What should I change my DNS to? Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-06 03:35 +0000
Re: What should I change my DNS to? F Volker <here@home.net> - 2016-09-06 13:48 +0700
Re: What should I change my DNS to? William Unruh <unruh@invalid.ca> - 2016-09-06 07:25 +0000
Re: What should I change my DNS to? F Volker <here@home.net> - 2016-09-06 14:53 +0700
Re: What should I change my DNS to? Dan Purgert <dan@djph.net> - 2016-09-06 09:40 +0000
Re: What should I change my DNS to? William Unruh <unruh@invalid.ca> - 2016-09-06 10:35 +0000
Re: What should I change my DNS to? Dan Purgert <dan@djph.net> - 2016-09-06 11:09 +0000
Re: What should I change my DNS to? F Volker <here@home.net> - 2016-09-07 08:53 +0700
Re: What should I change my DNS to? William Unruh <unruh@invalid.ca> - 2016-09-07 08:24 +0000
Re: What should I change my DNS to? "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 14:02 +0200
Re: What should I change my DNS to? F Volker <here@home.net> - 2016-09-08 06:42 +0700
Re: What should I change my DNS to? "Carlos E. R." <robin_listas@invalid.es> - 2016-09-08 03:10 +0200
Re: What should I change my DNS to? F Volker <here@home.net> - 2016-09-08 09:43 +0700
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-06 21:36 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 00:48 +0200
Re: What should I change my DNS to? (combined response) William Unruh <unruh@invalid.ca> - 2016-09-07 08:18 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 14:08 +0200
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-07 21:52 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-08 00:52 +0200
Re: What should I change my DNS to? (combined response) F Volker <here@home.net> - 2016-09-07 09:13 +0700
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 04:26 +0200
Re: What should I change my DNS to? (combined response) F Volker <here@home.net> - 2016-09-07 09:41 +0700
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 14:11 +0200
Re: What should I change my DNS to? (combined response) F Volker <here@home.net> - 2016-09-07 10:59 +0700
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-07 06:53 +0000
Re: What should I change my DNS to? (combined response) Dan Purgert <dan@djph.net> - 2016-09-07 11:02 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 14:21 +0200
Re: What should I change my DNS to? (combined response) Dan Purgert <dan@djph.net> - 2016-09-07 14:09 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 21:53 +0200
Re: What should I change my DNS to? (combined response) Dan Purgert <dan@djph.net> - 2016-09-08 11:06 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-08 15:22 +0200
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-07 06:55 +0000
Re: What should I change my DNS to? (combined response) F Volker <here@home.net> - 2016-09-07 14:27 +0700
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-07 14:28 +0200
Re: What should I change my DNS to? (combined response) Stefan Monnier <monnier@iro.umontreal.ca> - 2016-09-07 09:32 -0400
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-07 21:50 +0000
Re: What should I change my DNS to? (combined response) William Unruh <unruh@invalid.ca> - 2016-09-07 08:29 +0000
Re: What should I change my DNS to? (combined response) F Volker <here@home.net> - 2016-09-08 10:15 +0700
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-08 19:34 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-09 03:56 +0200
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-09 20:55 +0000
Re: What should I change my DNS to? (combined response) "Carlos E. R." <robin_listas@invalid.es> - 2016-09-10 02:47 +0200
Re: What should I change my DNS to? (combined response) Bit Twister <BitTwister@mouse-potato.com> - 2016-09-10 08:27 +0000
Re: What should I change my DNS to? (combined response) Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-10 22:53 +0000
Re: What should I change my DNS to? "Carlos E. R." <robin_listas@invalid.es> - 2016-09-06 13:35 +0200
Re: What should I change my DNS to? Aragorn <thorongil@telenet.be.invalid> - 2016-09-06 14:06 +0200
Re: What should I change my DNS to? "Carlos E. R." <robin_listas@invalid.es> - 2016-09-06 14:27 +0200
Re: What should I change my DNS to? Dan Purgert <dan@djph.net> - 2016-09-06 13:03 +0000
Re: What should I change my DNS to? "Carlos E. R." <robin_listas@invalid.es> - 2016-09-06 17:01 +0200
Re: What should I change my DNS to? Dan Purgert <dan@djph.net> - 2016-09-06 16:25 +0000
Re: What should I change my DNS to? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2016-09-06 21:37 +0300
Re: What should I change my DNS to? "Carlos E. R." <robin_listas@invalid.es> - 2016-09-06 23:42 +0200
Re: What should I change my DNS to? F Volker <here@home.net> - 2016-09-07 09:26 +0700
Re: What should I change my DNS to? Roger Blake <rogblake@iname.invalid> - 2016-09-06 12:54 +0000
Re: What should I change my DNS to? F Volker <here@home.net> - 2016-09-07 09:28 +0700
Re: What should I change my DNS to? William Unruh <unruh@invalid.ca> - 2016-09-07 08:25 +0000
Re: What should I change my DNS to? Moe Trin <ibuprofin@painkiller.example.tld.invalid> - 2016-09-07 03:29 +0000
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