how to figure out why sites on my server aren't loading

Posted by Derek on Server Fault See other posts from Server Fault or by Derek
Published on 2012-06-08T13:52:12Z Indexed on 2012/06/08 16:42 UTC
Read the original article Hit count: 209

Filed under:

linux

|

dns

|

domain

|

ip

|

nameserver

I seem to randomly receive "page cannot load, cannot connect to server" errors for sites on one of my servers. when this happens, it seems to only happen on certain IPs or IP ranges at a time. I say this because while I'll get the error from my home laptop I'll be able to access the site fine from my work computer or from an offsite VPS.

DNS records should already be fully propagated as these records were updated months ago.

I have no idea how to diagnose what's going on. Is there a tool in cpanel or outside on the web that can help me figure out what's going on?

© Server Fault or respective owner

Related posts about linux

apt-get install and update fail

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've got a problem with apt-get update and apt-get install ... commands . every time update or installing fails and errors are : Get:1 http://dl.google.com stable Release.gpg [198B] Ign http://dl.google.com/linux/chrome/deb/ stable/main Translation-en_US Get:2 http://dl… >>> More
kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
Build-Essentials installation failing

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am having trouble accessing the several critical header files that show to be a part of the build process. The "Ubuntu Software Center" shows "Build Essentials" as installed: Next I did the following two commands, which did not improve the problem: ~$ sudo apt-get install build-essential [sudo]… >>> More
Updating Debian kernel

as seen on Super User - Search for 'Super User'
I'm trying to update my Debian machine to 2.6.32-46 (which is the new stable). However, after doing apt-get update my apt-cache search linux-image shows me: linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486 linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem linux-headers-2… >>> More
Serial connection over a single USB cable (Windows to linux, or linux to linux)

as seen on Server Fault - Search for 'Server Fault'
I'm helping out with a project for an embedded device that only has USB and no serial. This device is running Linux. These days, when we need to connect to a serial port on a device we typically use a USB to serial adapter (on something like a phone system or a load balancing device, etc). I would… >>> More

Related posts about dns

Master/Slave DNS setup vs. rsync'ed DNS servers

as seen on Server Fault - Search for 'Server Fault'
We currently have primary and secondary DNS servers on our corporate network. They are setup in a master/slave type setup, where the slave gets its DNS information from the master. I'm trying to figure out what the real advantage is for the master/slave setup instead of just setting up an automated… >>> More
Updating Windows DNS records from a remote windows DNS server

as seen on Server Fault - Search for 'Server Fault'
Does anyone know if it is possible for a windows 2003 DNS server to update the records for a domain so that it contains all the records of a domain of of a remotely based DNS server? Im almost certain that doesn't quite explain the problem so I shall illustrate with an example: We have two offices… >>> More
OpenVPN DNS: VPN DNS stomping local VPN

as seen on Super User - Search for 'Super User'
I've finally noodled with OpenVPN enough to get it working. Even better, I can mount samba drives, ping network machines through the TUN device, etc - it's all great. However, I'm noticing that if I have the directive: push "dhcp-option DNS 10.0.1.1" # Push our local DNS to clients Then some of… >>> More
Random DNS Client Issue with BIND9/Windows Server 2003 DNS

as seen on Stack Overflow - Search for 'Stack Overflow'
Within our office, we have a local server running DNS, for internal related "domains", (e.g. .internal, .office, .lan, .vpn, etc.). Randomly, only the hosts configured with those extensions will stop resolving on the Windows-based workstations. Sometimes it'll work for a couple weeks without issue… >>> More
DNS Tools - DNS and Few of its Concerning Terms and Tools

as seen on Article City - Search for 'Article City'
A DNS or Domain Name System lets you locate computers on a network or the Internet TCP/IP network by domain name. The DNS server sustains a database of domain names or host names along with their cor... [Author: Daisy Osbaldo - Computers and Internet - April 02, 2010] >>> More