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#1 2018-02-05 23:09:14

anark10n
Member
Registered: 2012-10-13
Posts: 211

[Resolved] Some web servers unreachable

Hey there,

Ran a recent update of my system, and figured everything was a-okay since I could reach the internet without issue, but I started to notice I was getting a lot of "server not found" pages from links I would clicked. these looked like relatively obscure websites and thought nothing of it. And then it happened to sites I knew were working, e.g. cacert.org, or pythonanywhere.com.

Trying to ping them:

ping: pythonanywhere.com: Name or service not known

ping: cacert.org: Name or service not known

Trying to traceroute:

pythonanywhere.com: Name or service not known
Cannot handle "host" cmdline arg `pythonanywhere.com' on position 1 (argc 1)

cacert.org: Name or service not known
Cannot handle "host" cmdline arg `cacert.org' on position 1 (argc 1)

The commands worked after I changed the DNS entries (using wicd network manager) to global DNS addresses, when before I could reach them with just the default gateway configured as my DNS server. Any ideas on what to check as to what might have gone wrong?

Last edited by anark10n (2018-02-06 22:31:43)

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#2 2018-02-06 04:45:36

fukawi2
Ex-Administratorino
From: .vic.au
Registered: 2007-09-28
Posts: 6,223
Website

Re: [Resolved] Some web servers unreachable

Post the output of `ip a s`   `ip r s` and `cat /etc/resolv.conf`

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#3 2018-02-06 05:35:07

anark10n
Member
Registered: 2012-10-13
Posts: 211

Re: [Resolved] Some web servers unreachable

'ip a s' output:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp6s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 1c:1b:0d:39:ea:fc brd ff:ff:ff:ff:ff:ff
    inet 192.168.178.179/24 brd 192.168.178.255 scope global enp6s0
       valid_lft forever preferred_lft forever
    inet6 fe80::eddb:649:5fa:83d7/64 scope link 
       valid_lft forever preferred_lft forever

'ip r s' output:

default via 192.168.178.1 dev enp6s0 src 192.168.178.179 metric 202 
192.168.178.0/24 dev enp6s0 proto kernel scope link src 192.168.178.179 metric 202

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#4 2018-02-06 05:42:09

fukawi2
Ex-Administratorino
From: .vic.au
Registered: 2007-09-28
Posts: 6,223
Website

Re: [Resolved] Some web servers unreachable

`cat /etc/resolv.conf` was probably the most important output to be helpful tongue

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#5 2018-02-06 06:31:14

anark10n
Member
Registered: 2012-10-13
Posts: 211

Re: [Resolved] Some web servers unreachable

Crap, sorry about that.

cat /etc/resolv.conf

# Generated by resolvconf
nameserver 192.168.178.1
nameserver 208.67.222.222
nameserver 208.67.220.220

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#6 2018-02-06 15:04:47

ewaller
Administrator
From: Pasadena, CA
Registered: 2009-07-13
Posts: 19,774

Re: [Resolved] Some web servers unreachable

FYI, I can resolve the address, but ping is ineffective

ewaller@morhpheous ~ 1007 %ping pythonanywhere.com              
PING pythonanywhere.com (159.25.16.172) 56(84) bytes of data.
^C
--- pythonanywhere.com ping statistics ---
7 packets transmitted, 0 received, 100% packet loss, time 6076ms

ewaller@morhpheous ~ [1]1008 %

Edit:  What is your default gateway?  A home router? A Virtualbox host?
If it is a home router grade router with typically awful firmware, have you tried rebooting it?
What if you change from  openDNS to Google's DNS service (as an experiment).  IOW, change the second server in /etc/resolve.conf to 8.8.8.8

Last edited by ewaller (2018-02-06 15:12:43)


Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

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#7 2018-02-06 15:37:40

anark10n
Member
Registered: 2012-10-13
Posts: 211

Re: [Resolved] Some web servers unreachable

Default gateway is home router, and I have tried rebooting it thinking it was the router. Thing is, every other device can get to all of those sites just fine with the automatic DNS assignments, which is the router (192.168.178.1), it's only my machine that doesn't seem able to with the automatic DNS assignment. Also, I can reach all those sites with Google DNSs no problem, it's when I don't use any other DNS but the default gateway that I can't.

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#8 2018-02-06 15:46:34

ewaller
Administrator
From: Pasadena, CA
Registered: 2009-07-13
Posts: 19,774

Re: [Resolved] Some web servers unreachable

Are you running any kind of firewall? 
What is the output of hostnamectl  ?


Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

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#9 2018-02-06 20:53:27

seth
Member
Registered: 2012-09-03
Posts: 51,056

Re: [Resolved] Some web servers unreachable

dig pythonanywhere.com
dig @8.8.8.8 pythonanywhere.com
drill pythonanywhere.com
drill @8.8.8.8 pythonanywhere.com

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#10 2018-02-06 22:31:25

anark10n
Member
Registered: 2012-10-13
Posts: 211

Re: [Resolved] Some web servers unreachable

And now my machine is able to resolve the names without an issue, so above commands do outputs something useful, where before it was outputting empty records (when just using dig, not dig @8.8.8.8). I will see if this issue comes up again and try the commands to see what I get. For now, this is resolved i guess.

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