Re: Connection question

----- Original Message -----
From: "Craig Ringer" <craig(at)postnewspapers(dot)com(dot)au>
To: "Bayless Kirtley" <bkirt(at)cox(dot)net>
Cc: "List, Postgres" <pgsql-general(at)postgresql(dot)org>
Sent: Thursday, September 02, 2010 10:15 PM
Subject: Re: [GENERAL] Connection question

> On 2/09/2010 11:59 PM, Bayless Kirtley wrote:
>> Thanks a lot Craig. The register is connecting through localhost so it's
>> not that. I
>> guess I'm not surprised about the Windows thing. I suppose we'll just
>> have to
>> live with it then.
>
> I wouldn't be too sure yet.
>
> Did you run the test where you reboot the POS system with the ethernet
> unplugged? Does it still connect to the database OK?
>
> I didn't think XP broke TCP/IP connections to *localhost* when an ethernet
> interface went up or down, unless the connection was to a local IP
> associated with that interface. If you're connected to 127.0.0.1 from
> 127.0.0.1 it shouldn't, AFAIK, matter if you lose your wifi/ethernet.
>
> Come to think of it, you might want to check to make sure the local
> Ethernet interface is set to use DHCP. If it's using a static IP, Windows
> might permit that IP to be used to talk to the local host even when
> there's no link on the interface. So - to be sure, you can disable the
> Ethernet interface in the network control panel before your reboot for
> testing.
>
>
> Anyway, if you really can't make it work properly, there's a simple if
> mildly clumsy workaround. You can prevent XP from realizing it's lost its
> connection to the router by placing another device between the XP
> machine(s) and the router, like a plain old cheap switch. That way
> Ethernet link on the XP machines is never lost when you reboot the
> router - only between the router and the switch, where the XP machines
> can't tell. When the router goes down they lose their DHCP server, but
> that doesn't matter if it comes up again before they try to renew their
> DHCP leases, and for local-to-local traffic that's about all they'll be
> relying on the router for. You could even avoid that by setting static IP
> addresses.
>
> --
> Craig Ringer
>
> Tech-related writing at http://soapyfrogs.blogspot.com/

Hmmm, more to consider then. I have not done the test you suggested.
Guess I pounced on the Windows losing TCP/IP prematurely. It has
been a while but I think I set them up for static IP addresses initially. I
did check to be certain it is using localhost though. I will catch a slow
day soon and try your ideas. I'll report the results back soon.

Thanks Craig,
Bayless