some networking questions, I'm slightly confused

Rich Caloggero rjc at MIT.EDU
Mon Dec 10 13:39:42 EST 2001


OK, maybe this makes more sense to me now... If your dealing with a large
building then the pipe which comes into the building  better be "large
enough" to handle the entire building. This is most likely T1 or bigger
pipe. When dealing with phone lines coming into a house, for example, they
have already been branched off of the big trunk probably well before the
telephone pole on your block, and usually will only handle a few lines so
don't need to be very large in terms of band width.

                    Rich

----- Original Message -----
From: "Gregory Nowak" <gnowak1 at uic.edu>
To: <speakup at braille.uwo.ca>
Sent: Monday, December 10, 2001 11:15 AM
Subject: Re: some networking questions, I'm slightly confused


> As far as I know, the actual t1 line comes into the phone equipment which
is in the basement (in fact, the entire central
> switching office for this building is there). Then, as I understand it,
the digital signals
> for the t1 ride on the same cat5 wires
> in this building as the phone signals.
> If you just want to plug a phone in, you don't need anything
> between it and the jacks which are all standard rj11.
> If you have the internet service, you plug this box into the rj11,
> and it has an rj45 on it which hooks up to your nic.
> Like I said, I'll try to find out exactly what this is called and how
> to get more info on it.
> Greg
>
>
> On Mon, Dec 10, 2001 at 06:19:18AM -0700, Darrell Shandrow wrote:
> > Hi Gregory,
> >
> > If it is a T1 line, it needs two pieces of equipment, which may actually
be
> > built into a single device.  First, there is the CSU/DSU, which is like
a
> > modem for dedicated lines.  It is not, of course, a modem, but that is
its
> > metaphorical function in the dedicated environment.  It handles the line
> > coding, framing, signaling, etc.  Then there is some kind of protocol
> > router.  This is, of course, usually a router for the IP
> > protocols.  Perhaps, the device you're talking about is a combo CSU/DSU
and
> > router; though I know of no such device manufactured by HP.
> >
> > Regards.
> >
> > At 08:32 PM 12/9/2001 -0600, you wrote:
> > >I'm not sure how it is possible, but it is.
> > >I can find out more details.
> > >This is not cable or dsl, it is t1.
> > >Greg
> > >
> > >
> > >On Sun, Dec 09, 2001 at 07:24:53PM -0500, Rich Caloggero wrote:
> > > > Gregory Nowak wrote:
> > > > >They're running t1 over here through this HP networking gizmo that
> > > > >plugs into the phone jack, and has an rj45 jack on it.
> > > > How is this possible? How can you run T1 over a phone line, unless
perhaps
> > > > it were some dedicated phone line, in which case its usually termed
DSL for
> > > > dedicated subscriber line. Normal phone lines just don't have the
bandwidth
> > > > to do this. I assume the other side of this box is a standard
ethernet
> > > port?
> > > > We have such a box here at my house: one end plugs into a cable
modem and
> > > > the other has 4 ethernet ports which go to each of four computers.
We all
> > > > thus share the same cable connection. Its awesome!
> > > >
> > > >                     Rich
> > > >
> > > > ----- Original Message -----
> > > > From: "Gregory Nowak" <gnowak1 at uic.edu>
> > > > To: <speakup at braille.uwo.ca>
> > > > Sent: 06 December, 2001 10:52 PM
> > > > Subject: Re: some networking questions, I'm slightly confused
> > > >
> > > >
> > > > In kernel 2.4.16.
> > > > Greg
> > > >
> > > >
> > > > On Thu, Dec 06, 2001 at 07:56:42PM -0700, Darrell Shandrow wrote:
> > > > > Hi Gregory,
> > > > >
> > > > > On which Kernel version's source tree are you finding this
> > > information?  I
> > > > > do not find it in 2.4.6.
> > > > >
> > > > > Thanks.
> > > > >
> > > > > At 08:44 PM 12/6/2001 -0600, you wrote:
> > > > > >I am trying to do something like serial line load balancing, but
with
> > > > nics.
> > > > > >It is described in
/usr/src/linux/Documentation/networking/bonding.txt
> > > > > >.
> > > > > >Greg
> > > > > >
> > > > > >
> > > > > >On Thu, Dec 06, 2001 at 07:11:14PM -0700, Darrell Shandrow wrote:
> > > > > > > Hi Greg,
> > > > > > >
> > > > > > > Hmmm, this talk about bonding I am not understanding...  Are
you
> > > > trying to
> > > > > > > multihome with two different service providers?  Please
advise; I'm
> > > > > > > apparently missing something.
> > > > > > >
> > > > > > > Thanks.
> > > > > > >
> > > > > > > At 12:17 PM 12/6/2001 -0600, you wrote:
> > > > > > > >Yes, sort of.
> > > > > > > >I'll have to talk to the guy running the service here when he
gives
> > > > me my
> > > > > > > >second
> > > > > > > >connection, and see if I'll get another ip address or not,
and if he
> > > > > > knows
> > > > > > > >if his router will support  bonding.
> > > > > > > >Greg
> > > > > > > >
> > > > > > > >
> > > > > > > >On Wed, Dec 05, 2001 at 10:00:36PM -0700, Darrell Shandrow
wrote:
> > > > > > > > > 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
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > _______________________________________________
> > > > > > > > > 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
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > 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
>
>
>
>





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