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. Finally we recommend that you download and install on one of your PCs our network monitor utility called ZING which will show you visually the state (and performance) of your local network, your router, our network and the Internet backbone.

Q1. What is a Ping and what does it do?

Q2. I get a failure message from my browser when I try and reach a web site.

Q3. I cannot get my e-mail but I can browse the Internet.

Q4. I cannot get my e-mail and I cannot browse the Internet.

Q5. I am using ZING and it shows red indicators what do these mean?

Q6. I cannot access a site that I accessed yesterday (last week, last month).

Q7. Microsoft Explorer fails when I download from the ZyTrax web site.

Q8. How do I find out if I am connected to the Internet or not.

Q9. Diagnosing Network Problems.

Q10. What is a DNS and why do I need two of them?

Q.11 What is ZING?

Q12. What is a trace route (or tracert) command?

Q13. How do I find my TCP/IP configuration?

Answers

Q1. What is a Ping and what does it do?

'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 

1. Run a command prompt (sometimes called a 'DOS box') (Start/Programs/Command Prompt)
2. 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.zytrax.com' but this means the DNS service must be working.
3. 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

Were 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.

4. 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.

Q2. I get a failure message from my browser when I try and reach a web site.

Check the Zing values and status settings.

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 its this 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.zytrax.com'  If this works you are connected to the Internet and your DNS works so it is the web site or the backbone internet connection (check ZING for backbone errors). If not try 'ping 207.35.76.24' 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 Diagnosing Network Problems or contact us.

Q3. I cannot get my e-mail but I can browse the Internet.

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.

Q4. I cannot get my e-mail and I cannot browse the Internet.

You may be experiencing Internet connection problems. See Diagnosing Network Problems or contact us.

Q5. I am using ZING and it shows red indicators what do these mean?

ZING shows red indicators starting from the point at which it 'sees' network problems. Assuming 7 hops (the default setting). Then each hop (square) represents the following:

1st hop is your local router (if persistently red check here)

2nd hop is the ZyTrax Access router at our facility (if red starts here)

3rd hop is our proxy/firewall server (if red starts here)

4th hop is our local router to the Internet backbone (if red starts here)

5th hop (and higher) are the Internet routers (if red starts here)

Click the 'check' button and if the red is consistent then note the number of the FIRST red 'hop' (square) and contact us.

Q6. I cannot access a web site that I accessed yesterday (or last week or last month).

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 or contact us.

Q7. I get a failure when I try to use Microsoft Explorer to download from the ZyTrax web site.

If you are using Microsoft Internet Explorer version 5.00 then you may receive a failure message when trying to download from the ZyTrax web site. (To find out which version of Explorer you are using go to the help menu in explorer and click the About Internet Explorer button. The first line has the format 'Version 5.xx.yyyy' xx is the critical version number). To get round this problem you can do one of the following:

a. Download the latest version ( > 5.5) of Internet Explorer (www.microsoft.com/ie)

b. Use any Netscape browser.

c. Use an FTP client (e.g. CuteFTP or similar)

If the problems persists after trying any of the above methods contact our support service.

Q8. How do I find out if I am connected to the Internet or not?

Try 'ping www.zytrax.com' if this works you are connected to the internet and your DNS is working. If it fails see Diagnosing Network Problems or contact us.

Q9. Diagnosing Network Problems.

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.

1. Restart your PC - 90% of all problems disappear with this one act.

2. Check the link LEDs on your PC LAN card (if it has any)

3. 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 (see here for normal configuration). If they are not normal remove and immediately replace the power connection (WarpTwo.1) or switch the unit OFF then ON (WarpTwo.6). 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 - we can reach it and its LEDs are normal.

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:

hop 2 is the ZyTrax Access router - contact us.

hop 3 is the ZyTrax Proxy/firewall - contact us.

hop 3 is the ZyTrax backbone router - contact us.

hop 4 is the first backbone router - contact us.

hop 5 onward is the internet backbone - contact us.

In all cases when you call us tell us where you have reached in the above process. It will speed thing up considerably.

Q10. What is a DNS and why do I need two of them?

See our Registration and Domains FAQ.

Q11. What is ZING?

ZING is ZyTrax's Network and Router Monitor utility which runs on Windows '95, windows '98 and Windows NT (3.x and 4.x). (Screen shots). ZING runs in a very small window (and may be optionally run from the system tray), does not need any user configuration and does the following:

1. Monitors the state of your local router.
2. Monitors the state of the line and connection on each channel (for ISDN systems)
3. Monitors the state of the first n 'hops' in the Internet (you can decide how many hops to check)
4. Monitors the input and output throughput of your router every 8 seconds.
5. Maintains statistics for the previous 24 hours of usage giving maximum input and output performance, average input and output performance and total input and output data for every hour.

You can download and install ZING here.

Q12. What is a trace route (or tracert) command?

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. www.zytrax.com )

To run a tracert command:

1. Click start\programs\Command Prompt
2. Enter 'tracert 207.35.76.24 -d' (or www.zytrax.com -d). Replace the IP address with the one you want or use the URL of the site if you know it.
3. 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: 

1. 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.
2. You can abandon the command at any time by typing CTRL + C.

Q13. How do I find my TCP/IP configuration?

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):

1. Load a Command Prompt (a DOS box) (start/programs/Command Prompt)

2. If using windows '95 or Windows '98 enter

winipcfg - this will display your IP address, subnet mask and default gateway (local router)

3. 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:

1. Click start\settings\control panel

2. Double click 'Network'

3. Select 'Protocols' tab

4. Select TCP/IP then click 'Properties'

5. Navigate to the relevant tab to find the required information.