Jeff
10-23-2005, 11:45 PM
The following troubleshooting tips are covered in this guide:
1. Using the nslookup command
2. Using the tracert command
3. Using the telnet command
Myriad Network monitors its servers 24x7 in a number of different ways. We don't just check to see if the servers (hardware) are up, we also check to make sure each service (software - ie: ftp, web, imap, etc) is up. Our monitoring is done from multiple locations - both on site and off. That is, we don't just check each service from connection points local to our network, but also from several remote locations. In the unlikely event that, say, the Apache webserver stops handling requests, notifications are sent to Myriad Network network engineers at multiple locations. Some of the service checking utilities check every 5 minutes, some check every 2 minutes, and some check every 60 seconds. Some are built into the cPanel software, some are 3rd party utilities that cost money, and some are custom coded utilities written by Myriad Network engineers. They each have the same goal - ensuring the services required for our customers to maintain their businesses are up and running without issue, and letting us know if they are not. It is entirely possible for you to be unable to reach your website(s), even though they are fully functioning and operational. By following the steps in this guide, you will provide us with all the critical information we need to begin taking steps to troubleshooting connectivity issues. More importantly, this information will assist us in an attempt to determine if there are connectivity issues on your end, on our end, or somewhere in between.
Software that allows an end user to connect to a service on the Internet greatly simplifies the connection and data transfer process. Most of what takes place is done "behind the scenes", so to speak. This means that, when a browser is pointed to a site such as www.myriadnetwork.com (http://www.myriadnetwork.com), there is a great deal of magic taking place that many are not familiar with simply because such knowledge is not required. This includes, but is not limited to the following:
1. Obtaining the IP address of www.myriadnetwork.com (http://www.myriadnetwork.com) from a nameserver
2. Sending a connection request to the site's IP address (from your computer)
3. Receiving an acknowlegdement of the connection request (from our server)
4. Acknowledging the acknowledgement (from your computer)
Of course, none of these things could take place if there were not computers - routers - in between the requester's computer, and the destination computers.
Number 1 from above requires the following:
A. Your computer has a list of working nameservers
B. The nameservers are up and responding to requests
C. The path between you and those nameservers is functional and unrestricted
D. The nameserver provides you with the correct IP address(es) of the host you are going to be connecting to
Numbers 2 - 4 also require a functional and unrestricted path between you and the remote computer.
This troubleshooting guide is created to cover a few basic, yet very necessary steps that should be taken in the event that you are unable to reach your site(s). In the event that you are unable to reach your site(s), the output from the steps above needs to be included in a ticket that is opened with us. This guide assumes the user is working under the Windows family of operating systems.
DNS Resolution using nslookup
As mentioned above, before a connection can be made to a website, your computer must first obtain the IP address for the website. Here we will learn the "nslookup" command to obtain an IP address for a website.
1. Go to Start
2. Go to Run
3A. If using WindowsXP or Windows2000, type: cmd
3B. If using Windows95 or Windows98, type: command
4. Hit "OK"
Now you should be at a DOS prompt.
Type the following command: nslookup www.myriadnetwork.com (http://www.myriadnetwork.com)
Note: replace www.myriadnetwork.com (http://www.myriadnetwork.com) with your own website.
You should see output similiar to the following:
Server: vnsc-pri.sys.gtei.net
Address: 4.2.2.1
Name: www.myriadnetwork.com (http://www.myriadnetwork.com)
Address: 209.8.31.171
Every hostname on the Internet has an associated IP address. If it does not, then it is not reachable. If you are unable to reach a site, then it could possibly be because:
A. It does not have an IP address
B. The DNS servers for your network are not able to resolve the hostname to an IP address
If you find yourself unable to resolve a hostname, that does not necessarily indicate either A or B. It does indicate that getting a second opinion would be ideal. Getting a second opinion can be done by pointing your browser to www.dnsstuff.com (http://www.dnsstuff.com).
On the upper right side of www.dnsstuff.com (http://www.dnsstuff.com), at the top is a box titled "DNS lookup Enter domain or host name ?". The default value in the dropdown menu is "A".
Enter the following into that box, and hit the "Lookup" button: www.myriadnetwork.com (http://www.myriadnetwork.com)
Note: replace www.myriadnetwork.com (http://www.myriadnetwork.com) with your own website.
You should see the same IP address from the website as the one you received from the nslookup command. If you do not, realize that the one shown to you on www.dnsstuff.com (http://www.dnsstuff.com) is the correct IP address. It will always be the correct address for reasons (not caching) that will not be covered here.
* Be sure to include the output of the nslookup command, as shown above, for your site in the ticket.
Checking the path using tracert
If you are able to resolve the hostname, you are communicating with your ISP's nameservers just fine, and they have been updated at some point in time to provide you with the correct information.
The next step is to check your path to the website. We are going to trace the path from your local computer, to the Myriad Network webserver.
Open up a DOS prompt if necessary, and type the following: tracert www.myriadnetwork.com (http://www.myriadnetwork.com)
Note: replace www.myriadnetwork.com (http://www.myriadnetwork.com) with your own website.
The output should look similiar to the following:
6 14 ms 10 ms 11 ms bb1-tby-P0-2.atdn.net [66.185.136.164]
7 26 ms 27 ms 25 ms bb2-atm-P7-0.atdn.net [66.185.152.245]
8 39 ms 38 ms 37 ms bb2-vie-P4-0.atdn.net [66.185.152.32]
9 42 ms 37 ms 38 ms bb2-ash-P9-0.atdn.net [66.185.152.100]
10 38 ms 37 ms 39 ms pop1-ash-S1-0-0.atdn.net [66.185.144.195]
11 42 ms 39 ms 39 ms BeyondTheNetwork.atdn.net [66.185.144.206]
12 39 ms 38 ms 39 ms web.myriadnetwork.com [209.8.31.171]
Trace complete.
The output from the tracert command can be broken down as follows:
A. Notice that from my computer to the www.myriadnetwork.com (http://www.myriadnetwork.com) computer, there are 12 "hops".
B. It took approximately 39 milliseconds to reach the Myriad Network website.
C. the IP addresses for each router (hops 6 - 11 are routers, hop 12 is a server) have hostnames set up in DNS. Not all IP addresses have hostnames (but all hostnames should have IP addresses).
* Be sure to include the output of the tracert command, as shown above, for your site in the ticket.
Establishing a connection using telnet
Finally, we are going to attempt to establish a connection to the webserver from a DOS prompt. This is usually done via the browser, but for troubleshooting purposes, we are going to examine the output from the command line.
Open up a DOS prompt if necessary, and type the following: telnet www.myriadnetwork.com (http://www.myriadnetwork.com) 80
Note: Replace "www.myriadnetwork.com" in the example above with the name of your website.
If your DOS screen goes blank, then you have successfully connected to the website. It is important to include the "80" in the command, as that is the port that webservers run on by default.
If you find yourself at a blank screen, press the following to disconnect from the webserver:
A. Hold down "Ctrl", and press "]"
B. You should now be at a prompt that looks like the following:
Welcome to Microsoft Telnet Client
Escape Character is 'CTRL+]'
Microsoft Telnet>
C. Type: q
D. Hit Enter
You should now be back at the DOS prompt.
If you are unable to connect, you should see the following:
Connecting To www.myriadnetwork.com...Could (http://www.myriadnetwork.com...Could) not open connection to the host, on port 80: Connect failed
* Be sure to state in the ticket if you are able to connect to your site on port 80 or not.
Since copying and pasting is required for these steps, and since DOS does not have the copy+paste feature enabled by default for some reason, you can enable it by doing the following:
A. After opening a DOS window, left click on the upper left portion of the screen, on the little "C:\" icon
B. Click "Properties"
C. click the "Options" tab if necessary
D. Under "Edit Options", check the following box: "QuickEdit Mode"
E. Hit "OK"
F. You will be given the option to enable the settings for this window only, or for all future DOS windows.
After doing that, copying text from a DOS window is as follows:
A. Position the cursor over the text you wish to highlight
B. Hold down the left mouse button, and drag the cursor over the text to be highlighted. The highlighted text will be shown in white
C. After highlighting the required text, let go of the left mouse button, then click the right mouse button 1 time. Now the text is in your mouse buffer and ready to be pasted into an email or ticket. This text can be pasted by holding the "Ctrl" button, then hitting "v".
Summary
Although this guide is somewhat lengthy, a summary is as follows:
Open a DOS prompt, then:
1. Type: nslookup yoursite.com
2. Type: tracert yoursite.com
3. Type: telnet yoursite.com 80
Place the results from steps 1 and 2 in the ticket, and state whether you were able to connect in step 3 or not.
*** BONUS POINTS IF YOU TRY THE FOLLOWING: ***
4. Try another browser
5. Disable any personal firewall or other security software (anti virus) then try to connect again
6. Try connecting from another computer
7. After trying unsuccessfully to connect to your site, tell us if you can reach www.myriadnetwork.com (http://www.myriadnetwork.com)
8. Reboot (this does work in some cases for whatever reason)
Comments and feedback are welcome and encouraged. Feel free to post your thoughts or questions in this thread.
1. Using the nslookup command
2. Using the tracert command
3. Using the telnet command
Myriad Network monitors its servers 24x7 in a number of different ways. We don't just check to see if the servers (hardware) are up, we also check to make sure each service (software - ie: ftp, web, imap, etc) is up. Our monitoring is done from multiple locations - both on site and off. That is, we don't just check each service from connection points local to our network, but also from several remote locations. In the unlikely event that, say, the Apache webserver stops handling requests, notifications are sent to Myriad Network network engineers at multiple locations. Some of the service checking utilities check every 5 minutes, some check every 2 minutes, and some check every 60 seconds. Some are built into the cPanel software, some are 3rd party utilities that cost money, and some are custom coded utilities written by Myriad Network engineers. They each have the same goal - ensuring the services required for our customers to maintain their businesses are up and running without issue, and letting us know if they are not. It is entirely possible for you to be unable to reach your website(s), even though they are fully functioning and operational. By following the steps in this guide, you will provide us with all the critical information we need to begin taking steps to troubleshooting connectivity issues. More importantly, this information will assist us in an attempt to determine if there are connectivity issues on your end, on our end, or somewhere in between.
Software that allows an end user to connect to a service on the Internet greatly simplifies the connection and data transfer process. Most of what takes place is done "behind the scenes", so to speak. This means that, when a browser is pointed to a site such as www.myriadnetwork.com (http://www.myriadnetwork.com), there is a great deal of magic taking place that many are not familiar with simply because such knowledge is not required. This includes, but is not limited to the following:
1. Obtaining the IP address of www.myriadnetwork.com (http://www.myriadnetwork.com) from a nameserver
2. Sending a connection request to the site's IP address (from your computer)
3. Receiving an acknowlegdement of the connection request (from our server)
4. Acknowledging the acknowledgement (from your computer)
Of course, none of these things could take place if there were not computers - routers - in between the requester's computer, and the destination computers.
Number 1 from above requires the following:
A. Your computer has a list of working nameservers
B. The nameservers are up and responding to requests
C. The path between you and those nameservers is functional and unrestricted
D. The nameserver provides you with the correct IP address(es) of the host you are going to be connecting to
Numbers 2 - 4 also require a functional and unrestricted path between you and the remote computer.
This troubleshooting guide is created to cover a few basic, yet very necessary steps that should be taken in the event that you are unable to reach your site(s). In the event that you are unable to reach your site(s), the output from the steps above needs to be included in a ticket that is opened with us. This guide assumes the user is working under the Windows family of operating systems.
DNS Resolution using nslookup
As mentioned above, before a connection can be made to a website, your computer must first obtain the IP address for the website. Here we will learn the "nslookup" command to obtain an IP address for a website.
1. Go to Start
2. Go to Run
3A. If using WindowsXP or Windows2000, type: cmd
3B. If using Windows95 or Windows98, type: command
4. Hit "OK"
Now you should be at a DOS prompt.
Type the following command: nslookup www.myriadnetwork.com (http://www.myriadnetwork.com)
Note: replace www.myriadnetwork.com (http://www.myriadnetwork.com) with your own website.
You should see output similiar to the following:
Server: vnsc-pri.sys.gtei.net
Address: 4.2.2.1
Name: www.myriadnetwork.com (http://www.myriadnetwork.com)
Address: 209.8.31.171
Every hostname on the Internet has an associated IP address. If it does not, then it is not reachable. If you are unable to reach a site, then it could possibly be because:
A. It does not have an IP address
B. The DNS servers for your network are not able to resolve the hostname to an IP address
If you find yourself unable to resolve a hostname, that does not necessarily indicate either A or B. It does indicate that getting a second opinion would be ideal. Getting a second opinion can be done by pointing your browser to www.dnsstuff.com (http://www.dnsstuff.com).
On the upper right side of www.dnsstuff.com (http://www.dnsstuff.com), at the top is a box titled "DNS lookup Enter domain or host name ?". The default value in the dropdown menu is "A".
Enter the following into that box, and hit the "Lookup" button: www.myriadnetwork.com (http://www.myriadnetwork.com)
Note: replace www.myriadnetwork.com (http://www.myriadnetwork.com) with your own website.
You should see the same IP address from the website as the one you received from the nslookup command. If you do not, realize that the one shown to you on www.dnsstuff.com (http://www.dnsstuff.com) is the correct IP address. It will always be the correct address for reasons (not caching) that will not be covered here.
* Be sure to include the output of the nslookup command, as shown above, for your site in the ticket.
Checking the path using tracert
If you are able to resolve the hostname, you are communicating with your ISP's nameservers just fine, and they have been updated at some point in time to provide you with the correct information.
The next step is to check your path to the website. We are going to trace the path from your local computer, to the Myriad Network webserver.
Open up a DOS prompt if necessary, and type the following: tracert www.myriadnetwork.com (http://www.myriadnetwork.com)
Note: replace www.myriadnetwork.com (http://www.myriadnetwork.com) with your own website.
The output should look similiar to the following:
6 14 ms 10 ms 11 ms bb1-tby-P0-2.atdn.net [66.185.136.164]
7 26 ms 27 ms 25 ms bb2-atm-P7-0.atdn.net [66.185.152.245]
8 39 ms 38 ms 37 ms bb2-vie-P4-0.atdn.net [66.185.152.32]
9 42 ms 37 ms 38 ms bb2-ash-P9-0.atdn.net [66.185.152.100]
10 38 ms 37 ms 39 ms pop1-ash-S1-0-0.atdn.net [66.185.144.195]
11 42 ms 39 ms 39 ms BeyondTheNetwork.atdn.net [66.185.144.206]
12 39 ms 38 ms 39 ms web.myriadnetwork.com [209.8.31.171]
Trace complete.
The output from the tracert command can be broken down as follows:
A. Notice that from my computer to the www.myriadnetwork.com (http://www.myriadnetwork.com) computer, there are 12 "hops".
B. It took approximately 39 milliseconds to reach the Myriad Network website.
C. the IP addresses for each router (hops 6 - 11 are routers, hop 12 is a server) have hostnames set up in DNS. Not all IP addresses have hostnames (but all hostnames should have IP addresses).
* Be sure to include the output of the tracert command, as shown above, for your site in the ticket.
Establishing a connection using telnet
Finally, we are going to attempt to establish a connection to the webserver from a DOS prompt. This is usually done via the browser, but for troubleshooting purposes, we are going to examine the output from the command line.
Open up a DOS prompt if necessary, and type the following: telnet www.myriadnetwork.com (http://www.myriadnetwork.com) 80
Note: Replace "www.myriadnetwork.com" in the example above with the name of your website.
If your DOS screen goes blank, then you have successfully connected to the website. It is important to include the "80" in the command, as that is the port that webservers run on by default.
If you find yourself at a blank screen, press the following to disconnect from the webserver:
A. Hold down "Ctrl", and press "]"
B. You should now be at a prompt that looks like the following:
Welcome to Microsoft Telnet Client
Escape Character is 'CTRL+]'
Microsoft Telnet>
C. Type: q
D. Hit Enter
You should now be back at the DOS prompt.
If you are unable to connect, you should see the following:
Connecting To www.myriadnetwork.com...Could (http://www.myriadnetwork.com...Could) not open connection to the host, on port 80: Connect failed
* Be sure to state in the ticket if you are able to connect to your site on port 80 or not.
Since copying and pasting is required for these steps, and since DOS does not have the copy+paste feature enabled by default for some reason, you can enable it by doing the following:
A. After opening a DOS window, left click on the upper left portion of the screen, on the little "C:\" icon
B. Click "Properties"
C. click the "Options" tab if necessary
D. Under "Edit Options", check the following box: "QuickEdit Mode"
E. Hit "OK"
F. You will be given the option to enable the settings for this window only, or for all future DOS windows.
After doing that, copying text from a DOS window is as follows:
A. Position the cursor over the text you wish to highlight
B. Hold down the left mouse button, and drag the cursor over the text to be highlighted. The highlighted text will be shown in white
C. After highlighting the required text, let go of the left mouse button, then click the right mouse button 1 time. Now the text is in your mouse buffer and ready to be pasted into an email or ticket. This text can be pasted by holding the "Ctrl" button, then hitting "v".
Summary
Although this guide is somewhat lengthy, a summary is as follows:
Open a DOS prompt, then:
1. Type: nslookup yoursite.com
2. Type: tracert yoursite.com
3. Type: telnet yoursite.com 80
Place the results from steps 1 and 2 in the ticket, and state whether you were able to connect in step 3 or not.
*** BONUS POINTS IF YOU TRY THE FOLLOWING: ***
4. Try another browser
5. Disable any personal firewall or other security software (anti virus) then try to connect again
6. Try connecting from another computer
7. After trying unsuccessfully to connect to your site, tell us if you can reach www.myriadnetwork.com (http://www.myriadnetwork.com)
8. Reboot (this does work in some cases for whatever reason)
Comments and feedback are welcome and encouraged. Feel free to post your thoughts or questions in this thread.