ARIN allocating /20 netblocks?

Karl Denninger karl at
Sun May 17 23:59:35 UTC 1998

On Mon, May 18, 1998 at 12:36:26AM +0100, Alex Bligh wrote:
> > Let's not forget to mention the 10,000 dialup customers who have to 
> > change their DNS numbers.  We have sent snail-mail and e-mail over and 
> > over again, yet only about 1/3 of that 10k have actually made the change 
> > away from the old numbers.  How many of those customers do you think 
> > we'll lose when we officially turn off the old ip's?
> Keep a /32 route internally for your old DNS server numbers for a couple
> of years. Your customers will still see it, though noone else will. Of
> course your entire customer base will possibly lose connectivity
> to (1/2^32) of the internet - but they'd probably prefer that to losing
> their nameservers. If you want to be really cunning set the nameservers
> on the old box to resolve at a different server,
> which has a big notice to change their nameservers, plus a downloadable
> executable to go and do it for them on most operating systems. Presumably
> you are handing out dynamic DNS by radius in any case, which overrides
> the built in settings which copes with 95% of users.
> -- 
> Alex Bligh
> GX Networks (formerly Xara Networks)

You may be handing that out NOW (we are).

You weren't doing it two or three years ago.

We have a significant number of customers from *1993*.  There was no such
thing as dynamic auto-configuration of DNS at that point in time.

If you change those nameservers, you're going to have trouble.  Guaranteed.
I'll bet that not 10% of the customers with them hard-coded (of which there
will be MANY) will make the change *UNTIL* you shut off the old addresses -
at which point your NOC will find out what it is like to have a "bad hair"

Karl Denninger (karl at MCS.Net)| MCSNet - Serving Chicagoland and Wisconsin          | T1's from $600 monthly / All Lines K56Flex/DOV
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