ISP Network Diagnostics
The following FAQs are designed
to provide information that may assist you to get your service
operational as soon as possible. Our common goal is to keep your
Internet service operational, sometimes the problems are on your
site (or with individual PCs on your site). If we can, together,
find the location of the problem or even remove the possible
locations of the problem we can get you operational faster. If
in doubt call us but we would recommend experimenting with some
of the techniques listed below.
Q1.
What is a Ping and what does
it do?
A1.
'Ping' (actually its full name is
'ICMP Echo request') is a simple command that may be issued from
the DOS Command Prompt (Start/Programs/Command Prompt). Ping
tells you if you can contact an IP address. Basically it sends a
small message to another computer which causes the receiver to
echo back the same message (the message pings forward and back).
Ping is the simplest and most useful diagnostic tool to become
familiar with and well worth spending a few minutes
experimentation. To use Ping
-
Run a command prompt
(sometimes called a 'DOS box') (Start/Programs/Command
Prompt)
-
Type ping xxx.xxx.xxx.xxx
(where xxx.xxx.xxx.xxx is the IP address that you want to
check) followed by ENTER. You can also use a URL with a ping
e.g. 'ping
www.google.com' but this means the DNS service must be
working.
-
If the ping works (you have
successfully set a message to the remote computer and
received a response) you should get up to 4 replies of the
form
Reply from xxx.xxx.xxx.xxx:
bytes=32 time=yyms TTL=zz
Where xxx.xxx.xxx.xxx is the
IP address that is responding, yyms is the time (yy) in
milliseconds (ms) that the ping took and zz can be used to
calculate the number of routers that it passed through on
its journey.
-
If the Ping failed you will
see a message like:
Request timed out
Host unreachable
Network unreachable
Or something similar which
indicates a fault somewhere in the network. Note the failure
message and
contact us.
A2.
There are three possible causes
of this problem:
The web site is off the air or
otherwise unreachable.
Can you get to other web sites? If so,
then the problem lies with that
paticular web site. You have wait and keep
trying, it may be down or busy.
The DNS server is not
available or reachable.
Try 'ping
www.coool.ca' If this works you are connected to the
Internet and your DNS works so it is the web site or the
backbone internet connection . If not try 'ping
64.42.235.134' if this
works then you are connected to the internet but the DNS is
not working. Check your network settings
(Start/Settings/Control Panel/Network then the 'Protocols'
tab, then select TCP/IP and click 'Properties'. Select the
DNS tab and check that the values are as defined
here if not update them to reflect these entries (you
may need to restart your PC). If they are change the same
issue a 'ping' to them both and if one works make sure it is
the first in the DNS list (few browsers actually try any
thing but the primary DNS). If both fail you may not be
connected to the internet so
contact us.
You are not connected to the
Internet.
If a ping to any of the DNS
does not work then you may not be connected to the Internet
(which may be your connection or it may be your local LAN).
See
A3.
This indicates your e-mail server
is probably not operational or very busy. If we supply your
e-mail
contact us or if not contact your e-mail supplier.
A4.You may be experiencing Internet
connection problems. See
Diagnosing Network
Problems.
A5.
There are many reasons for this
if you can browse other sites then it is most likely the web
site that is either down or very busy. If you cannot reach other
sites then see
Diagnosing Network Problems.
A6.
Try 'ping
www.coool.ca' if this works you are connected to the
internet and your DNS is working. If it fails see
Diagnosing Network
Problems.
A7. The following information is
supplied to assist you in diagnosing network problems. You may
also
contact us at any time.
To diagnose a network problem you
just start to verify the connections from a known starting point
(your PC) moving progressively further into the network until
you find the problem:
1. Always start with your own
PC (it regularly fails).
Issue a
ping to your
own PC (get
it's address here). If this fails restart your PC and
try the failing operation again.
Check with someone else in
the office - if you are the only person having the problem
you have already isolated it to your PC or its wiring. Now
you only have to find it - in all cases it is not a remote
network problem.
-
Restart your PC - 90% of
all problems disappear with this one act.
-
Check the link LEDs on
your PC LAN card (if it has any)
-
Check your cabling.
2. Now check your local
network.
Your local PC is OK - someone
else has same problem.
Ping the local router (its
address is the Default Gateway IP that you get
here). If
this fails we may have a problem with the local LAN or the
router.
Now you have to move from
your desk.
Find your router and check
its LEDs. If they are not normal
remove and immediately replace the power connection
or switch the unit OFF then ON.
Check that the LEDs are as defined
here after about 30 seconds if NOT
contact us.
Go back to your PC and retry
to ping your local router and then repeat the failing
operation.
If this still fails we need
to find out where the failure is.
3. Check the remote network.
Your local router is OK.
Issue a
tracert
command to 64.58.76.176 (www.yahoo.com) NOTE: always use the
-d option with this command and you can abandon it using
CTRL+C when you see two three consecutive rows of '*'.
Note the hop number of the
first failure and proceed as follows:
In all cases when you call us
tell us where you have reached in the above process. It will
speed thing up considerably.
A8.
A tracert (or trace route)
command tells you all the routers between your PC and the place
you want to trace to (can be either an IP address or a URL e.g. )
To run a tracert command:
-
Click start\programs\Command
Prompt
-
Enter 'tracert 64.58.76.176
-d' (or www.yahoo.com -d). Replace the IP address with the
one you want or use the URL of the site if you know it.
-
NOTE: The -d in the command
line stops a reverse DNS lookup and speeds up the command
considerably.
tracert outputs the following
display:
a bbbb cccc dddd
ee.ee.ee.ee
Where:
a is the hop number
starting from 1
bbbb is the time is
milliseconds that the first attempt took to reach the site.
Asterisk means it timed out.
cccc is the time is
milliseconds that the second attempt took to reach the site.
Asterisk means it timed out.
dddd is the time is
milliseconds that the third attempt took to reach the site.
Asterisk means it timed out.
ee.ee.ee.ee is the IP
address of the router at this hop number.
NOTES:
-
If you do NOT add the -d
then after the dddd entry you will see a router name first
then an IP address in square brackets.
-
You can abandon the command
at any time by typing CTRL + C.
A9.
There are two methods of doing
this - the quick and the long method depending on how much
information you want:
The quick method (limited
configuration):
-
Load a Command Prompt (a DOS
box) (start/programs/Command Prompt)
-
If using windows '95 or
Windows '98 enter
winipcfg - this will
display your IP address, subnet mask and default gateway
(local router)
-
If using Windows NT enter
ipconfig - this will
display your IP address, subnet mask and default gateway
(local router)
The long method (full
configuration) - Windows '95, '98 and NT 4.x, Windows 2K:
-
Click start\settings\control
panel
-
Double click 'Network'
-
Select 'Protocols' tab
-
Select TCP/IP then click
'Properties'
-
Navigate to the relevant tab
to find the required information.
