Re: Choosing proxy on location

On Thu, 11 Nov 1999, Phillip Malone wrote:

> Recently we have put a proxy server in each of the offices. What I am
> after is a way to pick which proxy server a person connects to depending
> on the office they are in, but this needs to be dynamic. We thought of
> hard coding it to the local one, but there is a number of users that
> travel between the offices, and if they connected back to the main proxy
> it would harm the link between the offices.

Phillip,

There are a number of solutions to this problem:

1. Use an "intelligent" DNS agent authoritative for a domain which hands
out the IP address of the "closest" server based on distributed metrics:

 - Cisco Distributed Director
 - Alteon Distributed Server Load Balancing
 - proprietary DNS hacks of various flavours

2. Use loopback routing for a particular IP address to which all your
proxies respond, and let your routers do the work.

3. Other routing-based solutions, such as if the DHCP subsystem hands out
addresses which are dependant on location, and hence you could route on
source addresses and point their request streams at particular servers.

anon, anon ...

The first option is expensive, except the software/DNS based hacks, but
DNS-based solutions have their own set of peculiar problems. The latter
option requires a decent routing infrastructure and some knowledge of
routing protocols and router configs and presents it's own problems.

How many users are you talking about? It's worth considering training
them to modify their own client configs depending on where they are
physically located. Very cheap.

J.

                     _______
+------------------ //////// -----+----------------------------+
| John V Cougar __ Big | Voice: 61 2 6208 1683 |
| Cache Manager / / /\ Pond +----------------------------+
| Telstra Internet \/_/ \ Direct | E-Mail: cougar@telstra.net |
+--------------------____/ -------+----------------------------+
Received on Thu Nov 11 1999 - 02:32:44 MST