Testing for MTU on a Good Line (2)

9. Connect to the internet then start MTUSpeed and select the "Utilities" tab.
   
10. Enter your ISP's MTU in the "MTU value to test" box
    
11. Type an IP address or name of a one of your ISP's servers in the "Name or IP of Host to ping" box.
    (Use the IP address of a news or mail server or some other such suitable box such as a web server or gateway)
    NB not all servers are set to respond to pings.
    
12. Press Test MTU to see the responses. If the terminal window disappears too quickly check the ping checkbox
    
13. If you are informed that the "packets need to be fragmented but the Don't Fragment bit was set" then you have set the MTU too large. Either your ISP doesn't know his own MTU or else you made a mistake entering the value.
    Reduce the value of the MTU under test until you get proper ping responses.
    

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