On Friday 05 Apr 2002 6:41 am, Alan Poulton wrote: > Thursday, April 04, 2002, 7:35:53 PM, Richard Cobbe wrote: > > First question: do you want your FQDN to be > > hotstuff.bc.hsia.telus.net? With exim, I ran into some problems with > > that (mail for [EMAIL PROTECTED] getting sent to my ISP and so forth). I > > ended up giving my system a hostname that wasn't valid outside my > > network, home.rcc. > > HMM! Interesting point! No, I don't want mail for [EMAIL PROTECTED] to get > sent to my ISP. In that case, should I change my hostname? Or is there > a way to prevent it from routing to my ISP? > > My etc/hosts now looks like this: > > 127.0.0.1 hotstuff.bc.hsia.telus.net localhost loopback hotstuff > 192.168.43.1 hotstuff.bc.hsia.telus.net hotstuff > > ----- > > I have a Dynamic IP through my ISP - should I have (or need) the second > line?
It seems to me it might be useful for you to take a step away from the problem and realise three things. 1) Its not your computer but each interface that has an IP address 2) Names (including FQDN) are ways of refering to the IP address and are converted between the two using a DNS (Domain Name Server). Within the internet system the authority for a name (e.g name.com) and the names with are further qualified extendsion (eg extension.name.com) are delgated when you register the domain name 3) E-mail addresses ([EMAIL PROTECTED]) are related because of MX records in the dns I have a linux box acting as a gateway on my home network. The outside world has a cable modem with a dynamically assigned IP address although I have had the same one for 6+months. Because of that stability, and because I have bought the domain name chandlerfamily.org.uk which is managed by domain name management company (they host the official DNS for chandlerfamily.org.uk) I am able to set up their DNS to reflect this IP address in the name home.chandlerfamily.org.uk The internal side of that gateway box is a LAN which that box has IP address 10.0.10.100 and all my home machines have names in the 10.0.10.xxx space. The DNS for that address space is hosted by me on the gateway box. Since NONE of these IP addresses or the names associated with then are to be made available to the outside world I run a DNS server on the box that allocates the name roo.home to 10.0.10.100 and names like kanger.home pooh.home etc to my internal network machines. So for my gateway box what is its FQDN. I have a choice - I can use either roo.home OR home.chandlerfamily.org.uk. I have chosen roo.home and thats what is in /etc/hostname. I mention e-mail addresses because others have although its a little bit of a red herring and irrelevent to your original question. As you see below I am using the chandlerfamily.org.uk address as my address. The DNS server for chandlerfamily.org.uk (see above) has a MX record that tells it the ip address of the mail server which will receive mail for my domain. Within the domain management company that server receives the mail and forwards it to my ISP under the e-mail address they happen to have given me ([EMAIL PROTECTED]). I use fetchmail to receive the mail from my isp and fetchmail sends it to a local mail server (exim) as though it should go to [EMAIL PROTECTED] Exim is configured (separately from the DNS) to decide how to manage mail. It will send assume any mail with domain names *.home or chandlerfamily.org.uk as local and will not use DNS MX record lookup to decide what to do. Instead it delivers to local mailboxs where my mail program can get at them. I have configured Exim to recognise addresses of the form [EMAIL PROTECTED] specially (for testing) and not to hold them local but to forward them to my ISP with the -outside tag removed. My ISP recieves the mail from me because it comes from an IP address of one of the boxes on its internal network (it does this check because the domain name is different to blueyonder.co.uk and it doesn't want to act as a relay for spammers but it does want to relay e-mail for its customers). It then forwards it by doing the DNS MX lookup and finding my domain management companies mail server (which eventually routes it all the way back to me as described above) -- Alan Chandler [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
