Blackhole DNS

Nate Campi nate at
Thu Feb 21 22:27:48 UTC 2002

On Thu, Feb 21, 2002 at 09:59:49PM +0000, Martin Stewart wrote:
> When a server is being accessed by clients with private addresses 
> (RFC1918) is it best practice to make the server's caching DNS server 
> authoritative for

This shouldn't be an issue. If a server is reachable by clients with
RFC1918 IPs, then the local nameservers should already be able to
resolve those IPs. This is simply proper administration.

Backbone routers should/would/will not route RFC1918 IPs so if you don't
have any local IPs like that, a server should never see them, and not
need to resolve them.

> I've recently seen a problem which I claimed might have been caused by an 
> outage (or us not being able to reach) the blackhole servers at blackhole-
> and I was wondering how other people solved that issue.

See above, it shouldn't be a problem. If it is, set a local nameserver
as authoritative for those IP ranges/zones and make any caches forward
requests for those zone/ranges to your authoritative nameservers.
Nate Campi     Job: hostmaster at and root at

"Confucius say: He who play in root, eventually kill tree." 

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