Re: Questions on Squid (dnsserver) and DNS

ok have you ever seen your /var/log/messages file just after restartin by
reconfiugre option its restart your DNS helpers it dose not mean that Your
DNS cache will lose..

With Regards
Ahsan Khan
----- Original Message -----
From: "Steve Snyder" <swsnyder@home.com>
To: "Ahsan Khan" <ahsank@one.net.pk>; "Squid Mailing List"
<squid-users@ircache.net>
Sent: Friday, December 03, 1999 3:27 AM
Subject: Re: Questions on Squid (dnsserver) and DNS

> 1a. Hmm. I don't see anything on that page directly related to DNS
> performance. Are you referring to the patch that enables dnsserver to
> return TTL values? There's also the advice to have ones nameserver on
> the same subnet, but I'm already doing that.
>
> 1b. I understand that it is not advised to run the nameserver and
> Squid on the same machine. Nevertheless, that is the situation I have
> to work with.
>
> 2. So I can assume that dnsserver is almost always querying my local
> nameserver in preference to my ISPs servers? Good. I expect that the
> desired IP address will often be found in BIND's cache.
>
> 3. The reconfiguring of Squid is related to DNS performance in that
> dnsserver will cache n IP numbers (1024 by default?) By reloading all
> the copies of dnsserver, that cached info is lost and must be regained
> in subsequent lookups by Squid.
>
> Thanks for the response.
>
>
> On Fri, 3 Dec 1999 02:50:29 +0500, Ahsan Khan wrote:
> >Dear Steve,
> >
> > Great Questions,,
> >
> >1:- As well as BIND and Squid Dnsserver is concern, Squid has an
option
> >to comple with your bind for optimum performance, see
> >http://squid.nlanr.net/FAQ and more over if i will be on your place, i
would
> >rather made a cache only DNS for My squid system so i got less time for
DNS.
> >
> >2:- Always Remmeber In resolve.conf Your DNS and every other thing will
look
> >for First IP for DNS query and until its fail it will be used for this.
If
> >its failed then it will try next one, you can increase or decrease the
> >timeout by recompiling the dns with proper modifications.
> >
> >3:- By resonfigureing the squid nothing happen mutch but yes a new
> >session of layer in memory waiting for finishing previous requests and
> >starting with new config. So i do not think so its related to dns unless
u
> >will restrat your dns,,
> >
> >
> >With Regards
> >Ahsan Khan
> >----- Original Message -----
> >From: "Steve Snyder" <swsnyder@home.com>
> >To: "Squid Mailing List" <squid-users@ircache.net>
> >Sent: Friday, December 03, 1999 2:21 AM
> >Subject: Questions on Squid (dnsserver) and DNS
> >
> >
> >> I am running Squid (2.2S5) on a Linux box (RedHat v6.0 / kernel
> >> v2.2.13) which is also running a nameserver (BIND v8.2.2-P5). Can I
> >> get some clarification on Squid's dnsserver vs. BIND?
> >>
> >> When I cannot resolve a name locally, I (BIND) query one of my ISP's 2
> >> nameservers. If that fails, I query a root nameserver. In short, my
> >> nameserver is a pretty standard setup.
> >>
> >> By default, Squid reads these entries from my resolv.conf (the last
> >> 2 addresses are also used as forwarders in my BIND configuration):
> >>
> >> nameserver 127.0.0.1
> >> nameserver 111.222.333.444
> >> nameserver 555.666.777.888
> >>
> >> So here, finally, are my questions.
> >>
> >> 1. Is there an advantage to directing Squid (dnsserver) to use only
> >> address 127.0.0.1 for name resolution, or would I just be creating a
> >> bottleneck? My thinking is that name resolution would be faster if
> >> all resolutions went through the local nameserver, rather than having
> >> dnsserver call one of my ISPs nameservers.
> >>
> >> 2. How frequently does dnsserver query the second or third nameservers
> >> read from resolv.conf? Can I assume that because my local nameserver
> >> is listed first, that the other server are rarely queried?
> >>
> >> 3. I reload Squid's dnsserver ("squid -k reconfigure") on a weekly
> >> basis in the course of updating my URL redirector. This causes the
> >> loss of any IP/name data cached by dnsserver. In contrast, my local
> >> nameserver is rarely restarted, so the info it has cached is retained
> >> for a longer period. Does this information (relative duration of
> >> cached data) affect the optimal relationship between dnsserver and
> >> BIND?
> >>
> >> Thank you.
> >>
> >>
> >> *** Steve Snyder ***
> >>
> >
>
>
> *** Steve Snyder ***
>
Received on Thu Dec 02 1999 - 15:50:07 MST