How to send an update to servers that cached my dns info

[Kevin Darcy]

ignoramus10115 at NOSPAM.10115.invalid wrote:

> I have a domain algebra.com. One host had to quickly change the ip address.
> Even though (I thought) I specified a short time to live:
>
>                                         2001081002       ; Serial
>                                         7200    ; Refresh
>                                         900     ; Retry
>                                         72000 ; Expire
>                                         600)  ; Minimum
>
> many nameservers apparently still have the old info in caches.
>
> Is there any tool to notify them of the change.
>
> I realize that I do not have the list of servers that cached that
> address, but at least I could do it with the major ISPs, aol, earthlink
> etc.

No, there's no way to do such a thing. There is a protocol extension called
NOTIFY, but that's just used to notify slaves that they should refresh from
their master(s). There's currently nothing that would trigger an ordinary
caching server to fetch a new version of a given name.

>
>
> Also, here's some tidbit that may be a clue: when I do a dig, there
> is a field reminding some time to live:
>
> ;; ANSWER SECTION:
> dsl.algebra.com.        5d23h53m43s IN A  216.254.54.22
>
> Does it mean that dsl.algebra.com expires in 5 days? Why would
> that be so?

 corbulon.video-collage.com, one of the published nameservers for the zone,
appears to be broken. It is answering non-authoritatively (i.e. it's
"lame") and the TTL it's giving for the dsl.algebra.com name is in excess of 6
days. Did you *recently* reduce the TTL values? It looks like this corbulon box
is answering from stale cache entries. Unfortunately, it's also giving out
NS records with >6-day TTLs on its answers, so even if you removed corbulon
from your NS records, the stale entries would still stick around for a while.


- Kevin