> From: Julian Opificius <[EMAIL PROTECTED]> > > In response to Dave Reeds post ... > > Well, in the absence of a response by a guru, here's the scoop on > forwarding ... > > Forwarding was intended to be used in larger networks where there are > multiple names servers. To minimize traffic to the "big cloud" one server > is nominated as a local master, and all other servers send their requests > to the forwarding server, wait a while, then go to the main upstream > servers themselves (which would happen if the forwarding server went down). > Assuming the forwarding server is functioning, it will cache the results of > resolves for subsequent reuse for other local requests, thus minimizing > traffic to the outside world. > > Note that the according to the design philosophy, forwarding server is > intended to be on your own network.
My ISP's nameserver is the closest on my network - correct? > In my case (and I suspect in yours), there is only one DNS machine. This > means that there is no concept of concentrating DNS calls through one > caching server, because there IS only one server. > If you set your own DNS server up to treat the upstream server as a > forwarding server (note the wording!), then it will do exactly what it > would do anyway, because there is no other LOCAL server for it to go to > first. Which means your configuration will work :-) > > <major clipage> > > Julian. Hmm, where are you quoting from? I read: http://www.linuxdoc.org/HOWTO/DNS-HOWTO-4.html <quote> In large, well organized, academic or ISP (Internet Service Provider) networks you will sometimes find that the network people have set up a forwarder hierarchy of DNS servers which helps lighten the internal network load and the load on the outside servers as well. It's not easy to know if you're inside such a network or not. But by using the DNS server of your network provider as a ``forwarder'' you can make the responses to queries faster and less of a load on your network. This works by your nameserver forwarding queries to your ISP nameserver. Each time this happens you will dip into the big cache of your ISPs nameserver, thus speeding your queries up, your nameserver does not have to do all the work itself. If you use a modem this can be quite a win. For the sake of this example we assume that your network provider has two name servers they want you to use, with IP numbers 10.0.0.1 and 10.1.0.1. Then, in your named.conf file, inside the opening section called ``options'', insert these lines: </quote> ----------------------------------------------------------------- The way I interpret that is that if an address cannot be resolved in my DNS cache, then it looks to my ISP's nameserver (and ideally finds the answer in its cache). Otherwise how is this any different than putting the ISP's nameservers in /etc/resolv.conf (I'm gathering that you're saying it's not any different). Here's another site that seems to match my understanding: http://www.thelinuxreview.com/howto/ppp/x1531.htm <quote> You can happily use the domain name servers located at your ISP. You can also set up a local caching only (secondary) name server that is brought up by the ip-up script. There is an advantage to running a local (caching only) name server: it will save you time and bandwidth (if you frequently contact the same sites during a long online session). The DNS configuration for a caching only nameserver (that uses a "forwarders" line in the named.boot file pointing at your ISPs DNS) is relatively simple. The O'Reilly book (DNS and Bind) explains all you'll need to know. </quote> ----------------------------------------------------------------- Dave _______________________________________________ Redhat-list mailing list [EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/redhat-list
