[j-nsp] Re: Juniper DNS cache

sthaug at nethelp.no sthaug at nethelp.no
Sat Dec 10 11:09:29 EST 2005

> > Juniper does not operate as a caching nameserver, therefore it has no DNS
> > cache. It will send new queries to its configured nameservers every time,
> > so if something isn't updating, it is the nameservers you are using.
> Even if a *nix box doesn't run BIND, djbdns or other caching
> nameservers, many run nscd ("name service cache daemon"), which caches
> all libc calls to the resolver. The FreeBSD under-the-hood in the
> routing engine has nscd enabled or disabled, and even if nscd is
> running what is configured in nscd.conf and nssswitch.conf  ?

As far as I know, what's under the hood is based on FreeBSD 4.x, which
has no nscd. Thus I believe the answer given earlier is correct, JunOS
does *not* cache DNS replies. A simple traceroute run several times on
the router, with tcpdump running on the configured name server, appears
to confirm this.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no

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