Re: Rookie Error?

Thanks, Jared.

comments in-line...

On Sun, 28 Nov 2004 20:21:08 -0800, Jared Still <jkstill@xxxxxxxxx> wrote:
> Sure, there here are in order of not working, and working.
> 
> [root@sherlock tmp]# netstat -an | grep 1522
> tcp        0      0 127.0.0.1:1522          0.0.0.0:*               LISTEN
> [root@sherlock tmp]# netstat -an | grep 1522
> tcp        0      0 0.0.0.0:1522            0.0.0.0:*               LISTEN
> tcp        0      0 192.168.1.101:1522      192.168.1.105:39986     TIME_WAIT
> 

IIRC this machine is White Box (similar to RH Enterprise 3) and the
closest reference I could find to the solution was in this metalink
document (and more generally in RAC docs):
http://metalink.oracle.com/metalink/plsql/ml2_documents.showDocument?p_database_id=NOT&p_id=287453.1
(see section #4 for /etc/hosts configuration and other goodies
specific to RHEL3 and SUSE Enterprise)

There must be something different with RHEL3 than Fedora 1 for
example. I tried to simulate your problem on Fedora 1:

/etc/hosts (supposedly wrong but allows remote connection)
127.0.0.1            localhost fe1-60.tec.com fe1-60

[root@fe1-60 root]# netstat -an | grep 1521
tcp        0      0 0.0.0.0:1521            0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:1521          127.0.0.1:44592         ESTABLISHED
tcp        0      0 137.27.40.60:44524      137.27.40.60:1521       TIME_WAIT
tcp        0      0 127.0.0.1:44592         127.0.0.1:1521          ESTABLISHED

/etc/hosts (corrected, also allows remote connection)
127.0.0.1            localhost
137.17.40.60      fe1-60.tec.com fe1-60

[root@fe1-60 root]# netstat -an | grep 1521
tcp        0      0 0.0.0.0:1521            0.0.0.0:*               LISTEN
tcp        0      0 137.27.40.60:44524      137.27.40.60:1521       ESTABLISHED
tcp        0      0 137.27.40.60:1521       137.27.40.60:44524      ESTABLISHED

The way I interpret these stats (correct me if I'm wrong) is that the
0.0.0.0 means the logical host, and the .0 address suffix typically
means a network segment vs NIC (NIC has 1-2XX).

I now understand. The problem occured because the local-loop (similar
to NIC) address 127.0.0.1 was LISTENing to port 1522. In both my cases
with Fedora 1 the 0.0.0.0 (logical host) address was LISTENing, and I
could not (figure out how to) reproduce the problem. Its seems obvious
now that I know what to look for. ;-)

I'm sure people with RAC experience consider this trivial, as well as
systems with many NIC cards and network segments. I've summarized it
so I can 'hammer it in my brain' and get feedback if I'm off track.

Thanks to MZ for the solution and explanation, and Jared for patience.

HTH

Regards,

Mike Thomas
--
http://www.freelists.org/webpage/oracle-l

Other related posts: