9.3.2 behavior - explain please

[Chris Buxton]

Had to be. There's no way two processes can actually bind to the same  
port. (Right?)

Regardless, one set of answers was coming over UDP while the other  
was coming from the TCP port. Hence, the two processes had gotten  
ahold of the two different ports.

Chris Buxton
Men & Mice

On Aug 2, 2007, at 6:29 PM, Barry Margolin wrote:

> In article <f8tc1m$2kg3$1 at sf1.isc.org>,
>  Chris Buxton <cbuxton at menandmice.com> wrote:
>
>> They weren't both bound to port 53/UDP. One was, while the other was
>> bound to port 53/TCP. How that transpired is anybody's guess, but
>> I've seen it before.
>
> So is lsof lying?  It says UDP for both of them below.
>
>>
>> Chris Buxton
>> Men & Mice
>>
>> On Aug 1, 2007, at 6:41 PM, Barry Margolin wrote:
>>
>>> In article <f8pa2b$d1v$1 at sf1.isc.org>, Pavel Urban <urbanp at mlp.cz>
>>> wrote:
>>>
>>>> Pavel Urban wrote:
>>>>> [root at dns ~]# lsof -i udp:53
>>>>> COMMAND  PID  USER   FD   TYPE   DEVICE SIZE NODE NAME
>>>>> named   6982 named   20u  IPv4 19672544       UDP  
>>>>> dns.iol.cz:domain
>>>>> named   6982 named   22u  IPv4 19672546       UDP  
>>>>> dns.iol.cz:domain
>>>>> named   6993 named   20u  IPv4 19672564       UDP  
>>>>> dns.iol.cz:domain
>>>>> named   6993 named   21u  IPv4 19672566       UDP  
>>>>> dns.iol.cz:domain
>>>>>
>>>>> Strange...
>>>>>
>>>>
>>>> Huh... I can see it now. There were indeed two instances of named.
>>>> How
>>>> could that happen I don't know... Thanks a lot!
>>>
>>> That's very strange.  It's not supposed to be possible for multiple
>>> processes to bind to the same local address and UDP port.  Are you
>>> sure
>>> 6993 and 6982 aren't threads of the same process?  On Linux, the PID
>>> identifies the thread, not the process.
>>>
>>> -- 
>>> Barry Margolin, barmar at alum.mit.edu
>>> Arlington, MA
>>> *** PLEASE post questions in newsgroups, not directly to me ***
>>> *** PLEASE don't copy me on replies, I'll read them in the group ***
>>>
>>>
>
> -- 
> Barry Margolin, barmar at alum.mit.edu
> Arlington, MA
> *** PLEASE post questions in newsgroups, not directly to me ***
> *** PLEASE don't copy me on replies, I'll read them in the group ***
>
>