Traffic Engineering

Alec H. Peterson ahp at
Sun Sep 21 12:16:34 UTC 1997

On Sat, Sep 20, 1997 at 03:17:14PM +0100, James R Grinter wrote:
> This is a problem I've been musing over lately.  The best way that I
> can see is to return suitable DNS answers to people.  This avoids
> the route instability problems that Sean comments on, above:
>  Client gets TCP session established.
>  Routes change, their inbound route now reaches a different system
>  which clearly doesn't know about the connection and *boom* goes
>  the TCP session.
>  Routes return to their previous situation but by this time it's too late.

Agreed, that is a large problem.  A DNS solution can be fairly
easially implemented to accomplish this.  With some more work, one
could implement some more intelligent selection criteria on the DNS
server (based on server load, availibility and the like).

> but with DNS you've still got to return a suitable answer. (You
> could route to your DNS server, but that doesn't address the
> asymmetry problems.)

I'm pretty sure I've figured out a way to address this issue.


|Alec Peterson - ahp at    | Erols Internet Services, INC.        |
|Network Engineer                    | Springfield, VA.                     |

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