: net_adm:ping not working -- still not answered

Serge Aleynikov <>
Fri Sep 1 21:48:45 CEST 2006


Try to add IPs of these hosts to your hosts file in:

C:\WINDOWS\system32\drivers\etc\

Serge

erlang wrote:
> pings work ok. My system runs everything I have ever thrown at
> it. cygwin, mysql, sql server, perl and php apps, anything that
> opens local ports for sommunication -- all perfect until now with Erlang.
> 
> I tried taking out the dash in the computer name,
> it makes no difference.
> 
> 
>> Does the following work?
>>
>>  C:\> ping localhost
>>  C:\> ping my-server
>>
>>
>>  If no, get them working before delving into the erlang ping.
>>  If yes, hmmm.  Not certain though maybe my-server hostname
>>  should be changed to myserver (possibly the dash is problematic).
>>
>>
>> ~M
>>
>> On Fri, Sep 01, 2006 at 10:54:35AM -0700, erlang wrote:
>>> Yes, you have shown the tests I am using, very simple cases. 
>>> But I get pangs, and timeouts.
>>>
>>> I agree it is probably due to a  misconfigured network. What I have
>>> is one Windows Server 2003 sp1 machine that is setup for a 
>>> peer-to-peer workgroup, with no local dns server, domain controller, 
>>> etc. I agree that my problem is most likely a network configuration 
>>> that is not Erlang friendly. I couldn't find a prerequisites list for Erlang 
>>> so I'm not sure what it needs. I have used many applications that have no
>>> problem opening ports on localhost.
>>>
>>>
>>>> Well, it should work.
>>>>
>>>> Try the following diagnosis:
>>>>
>>>> $ erl -sname a
>>>> $ erl -sname b
>>>>
>>>> ()> erl_epmd:names().
>>>> {ok,[{"a",43500},{"b",43505}]}
>>>> ()> inet:gethostbyname("my-server").
>>>> {ok,{hostent,"my-server",[],inet,4,[{192,168,0,100}]}}
>>>> ()> net_adm:ping('').
>>>> pong
>>>> ()> nodes().
>>>> ['']
>>>>
>>>>
>>>> And if that does not work as above try:
>>>>
>>>> $ erl -sname 
>>>> $ erl -sname 
>>>>
>>>> ()> inet:gethostbyname("localhost").
>>>> {ok,{hostent,"localhost",[],inet,4,[{127,0,0,1}]}}
>>>> ()> erl_epmd:names().
>>>> {ok,[{"b",43527},{"a",43530}]}
> adm:ping('').
>>>> pong
>>>> ()> nodes().
>>>> ['']
>>>>
>>>>
>>>> I am suspecting your machine may have misconfigured network.
>>>>
>>>> To make sure the cookie is the same, add the argument
>>>> -setcookie my-cookie4711
>>>> to the command line of both nodes, but if you have the wrong cookie,
>>>> the target node should print: 
>>>> =ERROR REPORT==== 1-Sep-2006::09:40:06 ===
>>>> ** Connection attempt from disallowed node  ** 
>>>> when net_adm:ping() fails.
>>>>
>>>>
>>>>
>>>> On Thu, Aug 31, 2006 at 09:29:48AM -0700, erlang wrote:
>>>>>> Sorry, this is indeed a typo in my email. Should be:
>>>>>> ()1> net_adm:ping('').
>>>>>>
>>>>>>> Hi, is the colon ":" just a typo in your email? It should be
>>>>>>> "@
>>>  you can see from the node name in the Erlang shell prompt.
>>>>>>> Best Regards
>>>>>>> Lennart
>>>>>>>
>>>>>>>> ()1> net_adm:ping('a:my-server').
>>>>>>>> I can't get the ping-pong distributed example to work, so I tried simply
>>>>>>>> pinging another node. This doesn't work either.
>>>>>>>>
>>>>>>>> os: windows server 2003, machine name is my-server.
>>>>>>>> EShell v5.5.1
>>>>>>>>
>>>>>>>> command lines: erl -sname a
>>>>>>>>                             erl -sname b
>>>>>>>>
>>>>>>>> ()1> net_adm:ping('a:my-server').
>>>>>>>>
>>>>>>>> always returns pang. The cookie file is being read, and the cookie is
>>>>>>>> the same in both nodes. What to try next?




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