I was doing some traceroute test yesterday, and today, my Mac terminal's user prompt becomes

`bogon:~ myUserName$`

Also when I'm doing traceroute like:

traceroute www.google.com

it stops with this log:

bogon (  1.158 ms  0.908 ms  0.746 ms is the address of my wireless router. I still can surf the internet though.

  • how long do you have it running ?
    – Ruskes
    Commented Mar 8, 2015 at 4:59
  • @Buscar웃 I'm not sure.
    – MeloS
    Commented Mar 8, 2015 at 5:00
  • well I just did it, and after 3 min or so and 13 steps it stops, but it does not changes my computer ID
    – Ruskes
    Commented Mar 8, 2015 at 5:03
  • @Dwayne bogon is your (bogus?) machine name and not your user name.
    – klanomath
    Commented Mar 8, 2015 at 7:47
  • @klanomath you are right, this part is machine name, and I have never changed my machine name. Also it is bogon, may be it means bog on?
    – MeloS
    Commented Mar 8, 2015 at 7:53

1 Answer 1


By some searching I found a solution to this problem.

First, change the DNS address in your network configurations to a better one, like google's Second, run sudo hostname theMachineNameYouWant in terminal.

The reason for this:

They say that when you are doing DNS lookup/reverse lookup, the DNS server can give your machine a host name, this function should be turned off for public DNS servers, but I don't know why the DNS server of my local ISP has it on.

Since my machine uses a router, so it has a IP like 192.168.0.x in LAN, I don't know why but when using traceroute, this IP will be sent to the DNS server for a reverse lookup, and since it is a reserved IP address, the DNS server returns a hostname as bogon, thus, changes my machine's hostname.

So what is bogon? Bogon means the type of IP addresses that should not appear in a traceroute, like a reserved IP address.

bogon on wikipedia.

  • I'd recommend changing the DNS settings on your router to use something other than your ISP's DNS servers. They are running some mis-configured DNS and who knows what that means they're doing with DNS. Bad ISP, bad.
    – Ian C.
    Commented Mar 8, 2015 at 17:09

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