Lanny Marcus wrote: > I am up and running on our normal IPCop box again. Last night, I > changed the DNS Settings in the ADSL Modem, from using the DNS Servers > at our local ISP, to those of opendns.com <http://opendns.com> and > that probably will help a lot, until I can get IPCop configured > properly for the Caching DNS Server. My understanding is that IPCop provides a Caching DNS *Proxy*, not a Caching Name Server. Being a proxy means it forwards any queries that it can't answer from it's own cache to full DNS Servers (caching or not). Once it knows the answer it will cache it locally and return that answer to local users without contacting the DNS server again - as long as it is valid to do so based on the cache time set for that particular domain. For exmaple, my domain's cache time is short because my server lives on a dynamic IP address, but google's cache time is long because their servers are on static IP addresses and caching for a long time is safe for the DNS client to do (no need to query often because the servers aren't moving). If your ADSL modem can act as a DNS server, then you can point IPCop to that for DNS, but you can't point IPCop to itself (127.0.0.1) because it is only a proxy - not a full DNS server. In my view, for DNS your IPCop box should be directed to:- 1) your ISP's DNS servers; or 2) public DNS servers; or 3) your ADSL modem which is using either of the above. As I've already mentioned in other replies on this topic, my IPCop server uses my ISP for DNS requests. This means my ADSL modem is bypassed for DNS queries, but I'm not even sure if it could respond to DNS queries. Even if it could, since the IPCop is a caching proxy, it will keep the query results as long as it is entitled to before re-querying the real DNS server again. Using the ADSL modem won't help here because it can't cache any longer than the IPCop box can, so it will have to query the real DNS server in this situation. My view is you might as well make the IPCop do that in one step - why involve the modem? Regards, Ian -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20080714/b5e4ffa5/attachment-0003.html> -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 3617 bytes Desc: S/MIME Cryptographic Signature URL: <http://lists.centos.org/pipermail/centos/attachments/20080714/b5e4ffa5/attachment-0003.bin>