some networking questions, I'm slightly confused

Thu Dec 6 00:00:36 EST 2001

Hi Greg,

Good deal; I'll be glad to do what I can to help, especially with a 
specific implementation.  Did you get your answers regarding the two NICs 
and the outside addressing?

Regards.

At 09:56 PM 12/5/2001 -0600, you wrote:
>Thanks for the info even though I knew 99% of that.
>I will be in touch if I need more help.
>Again, thanks for a very good explanation (it's certainly better then I 
>could've done (grin)).
>Greg
>
>
>On Wed, Dec 05, 2001 at 08:19:57PM -0700, Darrell Shandrow wrote:
> > Hi Greg,
> >
> > I have stayed out of this until now because I haven't really had any time
> > to respond properly.  My days are usually quite long lately.  Anyhow, I am
> > a sys admin for a regional ISP; perhaps, I can help you.
> >
> > A domain is registered through a registrar like Network Solutions or
> > register.com.  When the domain is registered, part of the required
> > information includes the IP addresses for the primary and secondary name
> > servers.  This information is then added to what are known as the root
> > servers, which tell the entire world which primary and secondary name
> > servers know how to answer lookup questions about your domain.  In other
> > words, the root servers delegate authority to the specified primary and
> > secondary name servers to answer questions concerning your domain
> > name.  You could run one or both of these name servers yourself or have
> > someone else do DNS.  It sounds like you are having someone else do 
> primary
> > and secondary DNS.  As I'm sure you already know, DNS is the domain name
> > system, which points domain names to IP addresses, and which allows us to
> > do neat things like browse to www.foxnews.com and send mail to
> > nu7i at azboss.net instead of having to know all kinds of awful IP addresses
> > just to perform the simplest of functions on the Internet.  So, DNS points
> > a domain name to an IP address, but how does it work?  DNS information
> > about a domain name is handled by name servers in the form of zone
> > files.  Your domain exists as a zone file on the primary name server, and
> > the secondary name server is usually set up as a slave to the primary.  In
> > other words, the secondary name server gets its information (the zone 
> file)
> > from the primary name server and holds onto it, just in case the primary
> > name server is unavailable for some reason.  The domain name system is
> > really a very large, world wide distributed database.  A domain name
> > contains various types of information which is managed in the form of
> > various types of records.  The first type of record is SOA, which stands
> > for start of authority.  This just specifies your primary and secondary
> > name servers.  You see, if things were set up a certain way, your primary
> > and secondary name servers could actually delegate authority for your
> > domain to still other name servers, but this is not common
> > practice.  Another important record type is the A record.  This is the
> > address record, and your domain could have multiple A records, 
> depending on
> > how many subdomains you have set up.  For example my domain name servers
> > have an A record for shandrow.com which points to 
> 206.124.184.77.  There is
> > also another A record for borg.shandrow.com, a subdomain, which also
> > happens to point to the same IP address, though it could just as easily
> > point to another IP address.  Another somewhat related record type is a
> > CNAME, which stands for canonical name.  These records are used like
> > aliases to point subdomains to other domains.  For example, I did use a
> > CNAME record to point www.shandrow.com to shandrow.com, which means it 
> also
> > has the IP address 206.124.184.77.  Yet another important record type is
> > the MX record.  MX stands for mail exchanger.  E-mail software uses these
> > records when figuring out how to deliver e-mail on the Internet.  These
> > records, numbered by priority, tell mail delivery software where mail
> > should go when destined for a particular domain.  For example, my first MX
> > record priority for shandrow.com (which is MX 10) points to
> > borg.shandrow.com.  That is ultimately pointing to the Sendmail server
> > which runs on the IP address 206.124.184.77.  But, again, this could have
> > just as easily pointed to any Sendmail server which was configured to
> > accept and deliver mail for the shandrow.com domain.  Additional MX 
> records
> > can be defined so that, if the server specified in the first priority MX
> > record is unavailable for some reason, mail delivery software will try a
> > second, third, fourth and so on server until it can deliver the mail.  I
> > could, if configured properly, have a MX 20 pointing shandrow.com to yet
> > another Sendmail server, which would be able to receive mail for
> > shandrow.com in the absence of the primary mail server.
> >
> > Finally, there is reverse DNS.  This does the reverse of the domain name
> > system; it translates IP addresses back to domain names.  You definitely
> > want to have your DNS administrator set this up for your domain, because
> > certain FTP sites, web sites and other types of services on the Internet
> > use reverse DNS information for security purposes; they want to see that
> > your forward DNS and reverse DNS point to the same place, or they may also
> > want to verify that you have a domain which is or is not registered in a
> > certain part of the world.  In my example, performing a nslookup on the IP
> > address 206.124.184.77 will tell you that it reverses to 
> borg.shandrow.com,
> > which is a valid subdomain pointing to that same IP address.
> >
> > Anyhow, this will either help you or confuse you.  Please let me know if I
> > can help you with specifics.
> >
> > Regards.
> >
> > At 06:38 PM 12/5/2001 -0600, you wrote:
> > >Well, I'll actually be running a mail server for the building in which 
> I live.
> > >Instead of being regularly payed, my current connection will be free, and
> > >I'll get a second free connection
> > >They're running t1 over here through this HP networking gizmo that
> > >plugs into the phone jack, and has an rj45 jack on it.
> > >
> > >
> > >The reason I'm asking about the dns stuff is because
> > >when I told the guy that I've looked at the mail admin docs, and am
> > >seriously considering running the server,
> > >his response to me was:
> > >"so, I'll need to get you a domain with primary and secondary dns 
> servers."
> > >I said yes to this, but am carious about how his dns servers will know
> > >where I exist
> > >since he didn't ask for the name of my box.
> > >I guess when he tells me he's got things set up,
> > >my first question to him will be,
> > >"what name do the dns servers know my machine by?"
> > >
> > >He's macroslop licensed, but not meaning to brag,
> > >I get the impression that I may know more then he does without a license.
> > >
> > >In case some of you reading my post now are remembering a few of my other
> > >posts, I decided
> > >that getting my own domain name wasn't worth it.
> > >He said that I could run a small web server here if I want. So, I don't
> > >think he'd
> > >have a problem with me running it as http://mybox.domain.
> > >
> > >This whole thing started when I got my service, and he came here to 
> get it
> > >all setup.
> > >Not only was he impressed that I was the only one in the building so far
> > >running anything other then windblows, but that it was Linux.
> > >After my configuring tcp/ip both in windows and in Linux while he just
> > >watched me do it and gave me my ip address and all the other stuff,
> > >I asked if I would get a mail account.
> > >He said no, because there is no body to run one yet.
> > >Then he tentatively asked if I would be willing to perhaps do it, I said
> > >I'd read the mailadmin docs and think about it,
> > >and you know the rest.
> > >
> > >He's also looking to hire someone to run apachee.
> > >But, I'm not touching that for now (grin).
> > >Sorry for the long and personal post, but since Geoff asked,
> > >I figured that some other people on this list may be wondering
> > >why I'm asking theese questions, some of which may sound
> > >dumb, but are for the most part so that I could make sure that what
> > >I know is actually correct.
> > >Greg
> > >
> > >
> > >On Thu, Dec 06, 2001 at 09:29:48AM +1000, Geoff Shang wrote:
> > > > On Tue, 4 Dec 2001, Gregory Nowak wrote:
> > > >
> > > > > 1. Say there is a primary and secondary dns servers on a domain
> > > called mydomain.
> > > > > Say also that there is a machine called mybox.
> > > > > Also, I have ip addresses for primary and secondary dns servers on
> > > mydomain.
> > > > > Assumming all of the above, and assuming that I have permission to
> > > officially be on mydomain which is a valid internet domain,
> > > > > what do I do on mybox so that it would be resolvable
> > > > > as mybox.mydomain on the net?
> > > >
> > > > Nothing.  It's the primary and secondary DNS servers that control 
> how your
> > > > host is resolved, not your box.  As long as mybox has the IP 
> address that
> > > > ns1.mydomain.com and ns2.mydomain.com think it has, you should be 
> good to
> > > > go.
> > > >
> > > > > 2. Say that I have to nics with 2 static ip address for the outside
> > > world.
> > > > > How do I set things up so that my box would use both
> > > > > nics for outside access instead just either one nic or the other?
> > > >
> > > > As Chris said, what comes in where will depend on what address it 
> is sent
> > > > to.  What goes out where depends on a few things.  If you want to 
> use one
> > > > interface to access a particular host or network, you can set up a 
> route
> > > > accordingly.  If you want to access everything with both, you might 
> be able
> > > > to put 2 default routes (i've seen it done but don't know if it 
> works and
> > > > if it's supposed to work).  I saw you've been looking at bonding which
> > > > might also work, but I don't know about it.
> > > >
> > > > Can I ask, why you have 2 NICs?  Is it just to get 2 addresses or 
> are you
> > > > connected to 2 networks?
> > > >
> > > > Geoff.
> > > >
> > > >
> > > >
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup at braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > >
> > >_______________________________________________
> > >Speakup mailing list
> > >Speakup at braille.uwo.ca
> > >http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup at braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
>
>_______________________________________________
>Speakup mailing list
>Speakup at braille.uwo.ca
>http://speech.braille.uwo.ca/mailman/listinfo/speakup