Network Question

Discussion in 'Computer Information' started by Jeff Strickland, Jun 17, 2008.

  1. <snip>

    OK, so regarding NAT (or perhaps calling it NAPT or PAT is more
    accurate)

    - routers n routing existed before PAT.
    - The RFC that defines routing (RFC 1812) does not mention PAT
    - Routers have the function of Routing , routing does not involve
    looking at tcp ports like PAT

    I would suspect that if a user on DSL, and you have a router-modem (A)
    and a router(B) connected to it.
    You can/should disable NAT on B. It will route fine.

    The NAT function can be performed on one computer or appliance,
    separately from the routing function.

    And as an additional side point. I have heard that some things that
    are marketted as firewalls might also do NAT, (but i'm sure they don't
    do routing)
     
    jameshanley39, Jun 22, 2008
    #21
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  2. Jeff Strickland

    Baron Guest

    http://computer.howstuffworks.com/router2.htm

    The router !
    It joins the two networks, passing information from one to the other
    and, in some cases, performing translations of various protocols
    between the two networks.

    See RFC1631
    http://www.faqs.org/rfcs/rfc1631.html
    That would depend upon what routing you require inside your network
    True !
    Its still a routing function !
    You need to read up on the equipment that you want to use ! Some do and
    some don't !
     
    Baron, Jun 22, 2008
    #22
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  3. Jeff Strickland

    Baron Guest

    Baron, Jun 22, 2008
    #23
  4. If the definition of router were joining 2 networks and passing
    information from one to another, then almost Any network device, is a
    router. A cable, a network firewall, a switch/bridge. An application
    layer web proxy.

    are they all routers according to you?
    the definition you provided, based on that article, was never meant to
    be a definition, (if it was then it's obviousy a poor one). It was a
    weak statement about what routers do. So weak that it covers what many
    network devices do.


    So by virtue of tha weak statement, that article "mentions" all those
    things. Other than that. That article does not mention NAT or PAT..

    You won't find any article saying that NAT, or that NAPT/PAT , are any
    part of routing.


    a network layer proxy server e..g one that just passes a packet on
    somewhere, or translates it - converting one network address to
    another, perhaps changing network protocol too Could even do NAT I
    suppose, but it's not a router. It has no routing table.. Or, to use
    terminology of the previous RFC(the one for gateways). It's not a
    gateway, it has no routing database.
    RFC 1631 - The IP Network Address Translator (NAT)
    "
    3.2 Routing Across NAT
    The router running NAT
    "

    Think about this.
    Do you really think you have a strong argument there?

    I said the RFC for Routers does not mention NAT
    That is proof that the NAT has nothing to do with routing.

    If it DID mention NAT, then that would not prove it, one would have to
    see what it says about it.

    Now.. It didn't mention NAT.

    But you have posted the RFC for NAT, saying it mentions routers.
    And better, it even refers to a router running NAT !

    NAT would be working in tandem with routers. And in so doing, since
    NAT is so simple, it would be common for the box known as a router to
    do NAT too.
    Infact, RFCs are written after the event, in order to reflect
    practical realities. Which are that many router boxes post NAT(I mean,
    developed after NAT), (particularly ones used by the public), do NAT
    too.

    I haven't read much about DHCP.. But I know what it does... and I
    notice you claimed - correctly - that it is not part of routing ,
    even though it is part of many routers used by the public today. Of
    course, the routing rfc does not mention it, because it's nothing to
    do with routing. But the DHCP RFC has this statement..
    Which seems to me to be similar logic to the NAT document..

    http://www.ietf.org/rfc/rfc2131.txt
    Dynamic Host Configuration Protocol
    "
    "BOOTP relay agent"

    A BOOTP relay agent or relay agent is an Internet host or router
    that passes DHCP messages between DHCP clients and DHCP servers.
    DHCP is designed to use the same relay agent behavior as
    specified
    in the BOOTP protocol specification.
    "

    So there you are, it refers to a router passing DHCP messages -
    presumably not all routers do it. And it gives

    Yet you claim - correctly - that DHCP has nothing to do with routing

    So just like the statement in the RFC about NAT. The same logic
    applies. When it refers to router running NAT, that does not mean that
    it is a router function..
    Router functionality is described in the router RFC.. And Routers
    existed before DHCP, just as they existed before NAT.

    RFCs are non exhaustive and describe events after the fact.. And that
    is a nuisance for programmers. And their terminology is sometimes not
    consistent between one RFC and another.. And only claims to be true
    for that RFC. But we are not facing that problem here!

    This is merely the logic of your argument that is at fault..

    i'm waiting to see how you can maintain that after this post.. Infact
    regarding the 3 points I made originally..
    That the router rfc doesn't mention NAT. That routers existed before
    NAT. and no article says that NAT/PAT is a router function .

    You made an attempt at arguing that an article did. Though if it did
    then so did everything else that you agree is not . So that didn't
    work.

    And you tried to show that the NAT RFC mentions routing. Or talk about
    a router doing it.. But that logic, because other RFCs for devices
    that you agree do not routing functions, use the same phraseology.

    You also said it was a -basic- router function.

    Howcome then a router sans modem do routing without NAT? (i haven't
    used one much, but I suspect this is the case). you haven't disagreed
    or corrected me there if that was wrong. If that is indeed the case,
    then it doesn't help your argument that it's a basic router
    function...
    Of course, neither does the fact that Routers pre-existed NAT.


    <snip>
     
    jameshanley39, Jun 22, 2008
    #24
  5. Jeff Strickland

    Baron Guest

    wrote:

    James I see no point in continuing this thread ! I have not the
    slightest interest in simply arguing ! You jumped in to make a
    correction that really had no real value in the context of the original
    post. By pretending that you wanted to be informed just to create an
    argument is a waste of my time.

    This thread is now closed. Period.
     
    Baron, Jun 22, 2008
    #25
  6. Maybe you get a kick out of thinking of yourself as a "teacher" who
    people ask for help, and then you help them. But anybody informs you,
    you don't appreciate it, you get upset.

    Yes, I asked you some questions, in the process of explaining far more
    things to you too.. You don't like it? Then you have a problem with a
    2 way discussion.

    I don't know who you think you are declaring a thread to be closed. It
    doesn't work like that deary. You want to quit responding, then quit
    responding. That's not "closing a thread". It's not a web forum run
    by a totalitarian pseudo-baron with delusions of power. You can always
    start up your own one of those!
     
    jameshanley39, Jun 22, 2008
    #26
  7. <top post>
    The card that accesses the Verizon system is a USB dongle, and the Windows
    Network Manager has no idea that the machine on the 'net because it is
    looking for activity from the NIC, not the USB.

    I will be connecting a cross-over cable so files and the printers can be
    shared among the two machines, but I have low confidence that the USB device
    that provides the Internet access will be accessible from the other machine.

    I created a Workgroup, but the architecture of the system is not correct,
    and the two machines do not talk to one another -- files are not visible,
    and neither machine shows up on the other machine's Network Neighborhood.


    </top post>
     
    Jeff Strickland, Jun 24, 2008
    #27
  8. Jeff Strickland

    Baron Guest

    Jeff Strickland Inscribed thus:
    You need to get the USB device working properly first. I have found
    that various forms of malware can stop these things from working as
    well so you need to check that also.
    Yes you will need that for machine to machine Ethernet connections.
    The easiest way is to use the "Files & Settings Transfer Wizard" !
     
    Baron, Jun 24, 2008
    #28

  9. The USB device works fine. The host that it is installed in reports IP
    config problems -- another machine with the same address, or some such
    thing. I was able to establish a connection between two machines, but the
    host machine would not share the USB device, and the device reported that
    there were two different Internet connections with the same IP address. I
    resolved the addressing issue by disabling the second machine's network
    connection.
     
    Jeff Strickland, Jul 3, 2008
    #29
  10. Jeff Strickland

    Baron Guest

    Mmm. I must admit I'm not surprised by that. The USB device does not
    have DHCP so all machines on the network must have different fixed IP's
    The machine with the USB device will probably need to do routeing. The
    gateway address will be that of the USB device.

    Just getting both machines to talk to each other via Ethernet is a
    start.
     
    Baron, Jul 3, 2008
    #30
  11. <snip>

    I haven't read all your posts to see your situation incase it is
    indeed a scattered description.

    But I have never had any such issue with USB wireless adaptors.
    They do the function of wireless NICS.

    So they connect to the router-modem. Wireless USB adaptors get their
    IP from there.
    Not like USB modems

    That's my experience of them anyway.

    I have had set machines up for people before, with some connected with
    a cable, others with wireless usb adaptors, no problems. Each device,
    the wired NIC or wireless adaptor, gets an IP from the NAT router.

    Now for some speculation.. and blatant blabbering.
    I don't know if you have a USB modem.. In which case.. I vaguely
    recall that sometimes or often they only allow one computer anyway.
    They send one public IP.(via DHCP I suppose) to any devices e.g. wired
    NICs. Or I suppose wireless usb adaptors. Speedtouch make such a
    common usb modem I think, and I think people call it a half bridge
    (something along the lines of it not doing routing!). That particular
    one I heard of didn't have a wireless feature i.e. wouldn't see
    wireless adaptors at all. But it is possible in theory for tere to be
    a usb modem like that that is wireless and only takes one comp.
     
    jameshanley39, Jul 4, 2008
    #31
  12. <snip>

    I haven't read all your posts to see your situation incase it is
    indeed a scattered description.

    But I have never had any such issue with USB wireless adaptors.
    They do the function of wireless NICS.

    So they connect to the router-modem. Wireless USB adaptors get their
    IP from there.
    Not like USB modems

    That's my experience of them anyway.

    I have had set machines up for people before, with some connected with
    a cable, others with wireless usb adaptors, no problems. Each device,
    the wired NIC or wireless adaptor, gets an IP from the NAT router.

    Now for some speculation.. and blatant blabbering.
    I don't know if you have a USB modem.. In which case.. I vaguely
    recall that sometimes or often they only allow one computer anyway.
    They send one public IP.(via DHCP I suppose) to any devices e.g. wired
    NICs. Or I suppose wireless usb adaptors. Speedtouch make such a
    common usb modem I think, and I think people call it a half bridge
    (something along the lines of it not doing routing!). That particular
    one I heard of didn't have a wireless feature i.e. wouldn't see
    wireless adaptors at all. But it is possible in theory for tere to be
    a usb modem like that that is wireless and only takes one comp.



    <JS>
    Yes, it's a wireless modem I suppose -- that's where it fits in the
    architecture anyhow. It lets its host connect to the Internet, and I was
    hoping it would also allow a client on the network to leverage the
    connection, but it will not. I get a report that two computers are using the
    same IP address, and that's illegal.

    </JS>
     
    Jeff Strickland, Jul 4, 2008
    #32
  13. the issue then, is not to do with it being wireless.
    It's the fact that it is not doing NAT.

    Cable modems (I have seen NTL cable modems, so talk from that
    experience. like the NTL 250). It had 2 sockets, one for USB network
    connection, one for Ethernet. You could only connect one computer to
    it. Because it had the one IP.
    I imagine that if one took a switch and connected it to it, then it
    would still have that problem.

    I have heard that on NAT Router/Modems. Where one can turn off NAT,
    aka just tell it to act as a "switch/bridge" - it will do the modem
    function too anyway. And then you login through windows (as one does
    with a USB DSL "half bridge" modem e.g. speedtouch 330
    http://en.wikipedia.org/wiki/SpeedTouch_330 ).
    You'd probably get the same effect doing that. Only one computer able
    to connect.

    Infact, if one took a speedtouch 330 (wired usb modem, and added a
    wireless access point, you'd probably get the same effect too - a
    wireless usb modem, of the half bridge kind).

    Now.. So, your problem is equal to the (no doubt commonly asked)
    problem, of how to connect 2 computers to a cable modem.
    (I could have said "to a usb dsl modem" or something, but anyhow. I
    figured cable modem was very common and end users would ask in those
    terms too, and get answers)

    I found 2 results on that.
    I have hardly researched it, only checked the first 2 links on it.
    One essentially says get a NAT Router. (that will hand out different
    IPs, one to each comp)
    The other says use ICS. It involves putting 2 NICs in one computer(or
    rather, having 2 NIs on it), connecting one to the USB modem, and one
    to the other computer. . ICS uses NAT, so it will make sure the comp -
    itself and the other one, have different IPs.

    So that's that solved. Be interesting to know of any other solutions..


    A point regarding dangers of a so-called direct conneciton and
    benefits of a NAT Router. (the so-called "direct connection" is so-
    called because it is more direct since it means no NAT Router. Just
    computer to modem -Cable modem or DSL modem. Or computer has PCI DSL
    Modem Or PCI Cable Modem - they do exist it seems!)

    I haven't used ICS before.. But certainly in the case of a NAT Router,
    it's actually typically more secure than a direct connection. .OR
    rather...
    A (colloqial-) "direct connection" to the internet, is typically
    insecure.
    Because if your machine gets hijacked e.g. you browse to a malicious
    site and get a malicious server(a trojan) running. Then there is
    nothing stopping harry the hacker from connecting to it(messing more
    with your computer, or using your computer to attack e.g. spam
    people). Whereas with a NAT Router, at least harry the hacker would
    have to get past the NAT Router somehow.
    The windows firewall would stop harry too, and would be fine, But, the
    reality is that if you ran as administrative, (which one prob did to
    get damaged through a browser hijack anyway), and if administrative,
    that malicious software could bring down or make an exception in your
    windows firewall. They often disable the windows firewall, it's a
    common target. Really the computer is compromised in this situation..
    So it's not really the windows firewalls fault. But in practice, NAT
    Routers are very helpful in providing some better security, than a so-
    called direct connection.
     
    jameshanley39, Jul 5, 2008
    #33
  14. On Jul 5, 11:45 pm, ""
    <snip>

    correction.
    with a USB modem, the usb port is I think an NI - network interface.
    So with ICS, you'd only need one additional NI. (most motherboards for
    years now have had an NI built in).
    So you won't even need anything new to do this (though it's always
    good to have NICs around, as it is working spares of any/every
    component or software).
     
    jameshanley39, Jul 7, 2008
    #34
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