From: | "D'Arcy J(dot)M(dot) Cain" <darcy(at)druid(dot)net> |
---|---|
To: | Greg Smith <gsmith(at)gregsmith(dot)com> |
Cc: | PostgreSQL Performance <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: Best way to index IP data? |
Date: | 2008-01-12 06:00:48 |
Message-ID: | 20080112010048.27678be8.darcy@druid.net |
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Lists: | pgsql-performance |
On Fri, 11 Jan 2008 21:56:38 -0500 (EST)
Greg Smith <gsmith(at)gregsmith(dot)com> wrote:
> On Fri, 11 Jan 2008, Steve Atkins wrote:
>
> > You may well need netmasks to configure your interface, but there's
> > absolutely no need for them to identify an IP endpoint, which is all you
> > need to identify the destination the packet is going to, and that is the
> > most common use of IP addresses.
>
> Technically you can't ever send a packet unless you know both the endpoint
> and your local netmask. As the sender, you're obligated to determine if
> the destination is on your local LAN (in which case you send it there) or
> if it goes to the gateway. That's similar to a routing decision, but it's
> not quite--if you don't have to look in a routing table, it's not actually
> part of routing.
Not sure what your point is here. Sure, you need the netmask but not
of every IP address you send to, only for the IP/network that you are
on. That's a grand total of one netmask per interface that you need to
know. And you don't store it in your database.
--
D'Arcy J.M. Cain <darcy(at)druid(dot)net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
+1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.
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