router vs. gateway

  • Thread starter Thread starter Peter Kaufman
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Peter Kaufman

Hi,

I would appreciate an explanation of the difference between a router
and a gateway. Is the term 'gateway' more or less obsolete now?

Thanks,

Peter
 
1. Router - This does exactly as its name says. It routes data between one
network and another. It is also capable of doing Nat too.
2. Switch - Just like a hub, but connections are direct from one machine to
the next via mac address rather than broadcast to everyone. This is good for
reducing excess network traffic and to prevent snooping on the network.
3. Hub - This simply routes data from one machine to another by mac address
but unlike the switch it does this data transfer via broadcast rather than
direct connect.
4. Bridge - A bridge again does exactly what its name implies. It joines two
networks together and creates a simple bridge between the two making them
one network, however, only data relavant to the opposing connected network
crosses the bridge. DHCP and other non-routable protocols are stopped at the
bridge. This is good if you need to control traffic and split a larger lan
into smaller sections.
5. Gateway - A gateway is simply a designated point on your network where
traffic not addressed to a machine or device on the local network is
forwarded to. An example of this would be your home network. Say you run a
192.168.0.0/24 subnetting scheme on your network. What this would mean in
regards to the gateway is, if the address you're trying to reach does not
reside in the 256 possible addresses in your subnet, the connection is
forwarded to the gateway which then talks to other routers connected to it
and tries to determine the best possible path to send the data on so that it
reaches its destination.

A gateway is a network point that acts as an entrance to another network.

Andy
 
From what I can tell a gateway is referred to as the router port that your computer
sends traffic to for traffic outside of your network and there is not a static route
for in your route table as shown by route print command. Hence gateway usually refers
to the router port IP for internet traffic. --- Steve
 
in message
: I would appreciate an explanation of the difference between a router
: and a gateway. Is the term 'gateway' more or less obsolete now?

A router can be a gateway or have multiple gateways. A router is a network
device that connects two or more dissimilar networks. A gateway, default or
not, is a path to another network.

--
Roland Hall
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I'm going to disagree with the gateway as defined here in the other
replies. The early original term Gateway was in reference to a "Protocol
Gateway" where protocol conversion took place. For example it took something
to act as a protocol gateway so that a system running only IPX/SPX could
communicate with a system running only TCP/IP. Another example might be a
system running Token Ring vs a Novel IPX/SPX.

But yes in recent times it is almost synonymous with a router. However the
term router generally is a specific hardware device while "gateway" is more
of a logical concept.

Of course now the term router is used so much for a "Broadband NAT Device"
which aren't even really routers,..that when you want to talk about a *real*
router (Cisco 2501, 2600, 1700, ect) nobody even knows what your talking
about anymore.
 
in message
: I'm going to disagree with the gateway as defined here in the other
: replies. The early original term Gateway was in reference to a "Protocol
: Gateway" where protocol conversion took place. For example it took
something
: to act as a protocol gateway so that a system running only IPX/SPX could
: communicate with a system running only TCP/IP. Another example might be a
: system running Token Ring vs a Novel IPX/SPX.
:
: But yes in recent times it is almost synonymous with a router. However the
: term router generally is a specific hardware device while "gateway" is
more
: of a logical concept.
:
: Of course now the term router is used so much for a "Broadband NAT Device"
: which aren't even really routers,..that when you want to talk about a
*real*
: router (Cisco 2501, 2600, 1700, ect) nobody even knows what your talking
: about anymore.

Phillip...

*real* router?

Are you saying these "Broadband NAT Devices" do not route packets from one
network to another?

Cisco's words...

NAT operates on a router...
http://www.cisco.com/warp/public/cc/pd/iosw/ioft/iofwft/prodlit/iosnt_qp.htm

Webopedia says a gateway is an earlier term for a router . I disagree. In
early web days people often called their ISP their server. They thought
they routed through their ISP's web server to get to the Internet. That
doesn't make it true just because some people referred to it that way.
http://webopedia.com/TERM/g/gateway.html

Gates have been around a lot longer than computers and I'd bet this was not
the original term for a gateway either.
http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=gateway

My view is a gateway, at least in the reference posed, is more like a route
which I would tend to believe would be its original meaning long ago. The
DFG (default gateway) is actually the default route on a router. It is the
route a packet takes when there are no known routes for a targeted network.

A gateway to a new dimension...
A gateway into the unknown...
The gateway to the North...

.... and it's also the name of a computer manufacturer. Moo!


--
Roland Hall
/* This information is distributed in the hope that it will be useful, but
without any warranty; without even the implied warranty of merchantability
or fitness for a particular purpose. */
Online Support for IT Professionals -
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As far as the deal with the gateway thing, what I said comes from the Cisco
CCNA material, it isn't just something I just came up with on my own.

On to the router thing.....
*real* router?

Are you saying these "Broadband NAT Devices" do not route packets from one
network to another?
Click to expand...

No I am not saying that. Proxys can also get a packet from one network to
another, but they aren't routers either.
NAT operates on a router...
Click to expand...

Yep, it does. But it is a feature of the router that can be turned off and
the router will just follow normal Layer3 routing. I could turn our old
Cisco 2501 into a NAT Device (or NAT Firewall) if I really wanted to.
However, a NAT Device (like hardware firewalls and those SOHO things) cannot
have NAT turned off and cannot fuction as a normal layer3 router.

A router can double as a NAT Device, but a NAT Device cannot double as a
router. The "terminology crisis" (my own term for it) is caused by allowing
marketing departments to rewrite the dictionary to be able to sell something
instead of calling things what they really are. What are commonly called
Cable/DSL Routers should more accuartely be called either "Cable/DSL NAT
Servers" or possibly "Cable/DSL Firewalls" since their actual function and
design more closely match that of the common firewalls like Watchgaurd, PIX,
etc., although their security and features aren't as robust. I don't see
people with firewalls like PIX, Checkpoint, or Watchgaurd going around
calling thier boxes "routers" just because they manage to get a packet from
one network to another.

I guess terminology is a little pet-peve of mine. Much of the problems and
hassles of trying to answer people's questions in these groups is due to
"butchered" terminology that create a situation where nobody really knows
what anybody else is really talking about.

........and don't get me started on Cable/DSL "modems" which aren't real
"modems".... :-)
There isn't a one of them that "modulates & demodulates" whic is what the
name means (modulator/demodulator = "mo - dem"). They are just a stupid
"media converter".

Anyway Roland,...I been meaning to ask but haven't seen you around
lately,....are you planning to go to the MVP Mini-Summit? I missed a lot of
people back in April becuase the crowd was so large. The Security based
Summint in Nov should be smaller so maybe I can actually find more of the
folks I'd like to see this time.
 
: :
: As far as the deal with the gateway thing, what I said comes from the
Cisco
: CCNA material, it isn't just something I just came up with on my own.
:
: On to the router thing.....
:
: > *real* router?
: >
: > Are you saying these "Broadband NAT Devices" do not route packets from
one
: > network to another?
:
: No I am not saying that. Proxys can also get a packet from one network
to
: another, but they aren't routers either.
:
: > NAT operates on a router...
:
: Yep, it does. But it is a feature of the router that can be turned off and
: the router will just follow normal Layer3 routing. I could turn our old
: Cisco 2501 into a NAT Device (or NAT Firewall) if I really wanted to.
: However, a NAT Device (like hardware firewalls and those SOHO things)
cannot
: have NAT turned off and cannot fuction as a normal layer3 router.

I don't see a firewall as a NAT device although it may support NAT
functionality. I agree SOHO routers are limited, with the price to match,
but they do perform routing functions.

: A router can double as a NAT Device, but a NAT Device cannot double as a
: router.

I'm not clear on that statement.

: The "terminology crisis" (my own term for it) is caused by allowing
: marketing departments to rewrite the dictionary to be able to sell
something
: instead of calling things what they really are.

Now, don't get ME started no marketing departments. Wish they were in
season.

: What are commonly called
: Cable/DSL Routers should more accuartely be called either "Cable/DSL NAT
: Servers" or possibly "Cable/DSL Firewalls" since their actual function and
: design more closely match that of the common firewalls like Watchgaurd,
PIX,
: etc., although their security and features aren't as robust. I don't see
: people with firewalls like PIX, Checkpoint, or Watchgaurd going around
: calling thier boxes "routers" just because they manage to get a packet
from
: one network to another.

That might also be because their target is to sell firewall functionality.
If a firewall appliance does not route a packet, then it functions as a
bridge, does it not?

: I guess terminology is a little pet-peve of mine. Much of the problems and
: hassles of trying to answer people's questions in these groups is due to
: "butchered" terminology that create a situation where nobody really knows
: what anybody else is really talking about.

My favorite is "domain".

: .......and don't get me started on Cable/DSL "modems" which aren't real
: "modems".... :-)
: There isn't a one of them that "modulates & demodulates" whic is what the
: name means (modulator/demodulator = "mo - dem"). They are just a stupid
: "media converter".

A transceiver?

: Anyway Roland,...I been meaning to ask but haven't seen you around
: lately,....

Sometimes work calls...

: are you planning to go to the MVP Mini-Summit?

I wasn't invited. I'm not an MVP, except on Singapore Airlines. (O;=

: I missed a lot of
: people back in April becuase the crowd was so large. The Security based
: Summint in Nov should be smaller so maybe I can actually find more of the
: folks I'd like to see this time.

Hope so. BTW... Cisco is my switch/router of choice, except for the 700
series, which they bought from someone else and they don't even make good
parking blocks.

--
Roland Hall
/* This information is distributed in the hope that it will be useful, but
without any warranty; without even the implied warranty of merchantability
or fitness for a particular purpose. */
Online Support for IT Professionals -
http://support.microsoft.com/servicedesks/technet/default.asp?fr=0&sd=tech
How-to: Windows 2000 DNS:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;308201
FAQ W2K/2K3 DNS:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;291382
 
Roland Hall said:
I don't see a firewall as a NAT device although it may support NAT
functionality.
Click to expand...

Never seen one that wasn't a NAT Device. Of course I am talking about the
firewall appliance or computer based firewall,...not those software based
"personal firewalls" like ZoneAlarm, ICF, etc.
: A router can double as a NAT Device, but a NAT Device cannot double as a
: router.

I'm not clear on that statement.
Click to expand...

A router can be made a NAT Device by enabling NAT and [optionally] setting
up ACLs. However, a NAT Device (Hardware, Cable/DSL "routers", ect) can not
have NAT turned off and will always have a "trusted" vs "untrusted" network.
They cannot have these things turned off and let you stick the thing in the
middle of a LAN between two LAN segments and use it like you would use a
Cisco 2600 Series to route normal LAN traffic. They are dedicated NAT
devices and they should be marketed as such and not be called "routers". I
would be satisfied with "NAT Server" or even "Firewall" but not "router".
That might also be because their target is to sell firewall functionality.
If a firewall appliance does not route a packet, then it functions as a
bridge, does it not?
Click to expand...

No. Bridging is done across like subnets where it is the same subnet on both
sides of the device. Common network Switches are "bridges",...multi-port
bridges to be more accuarte as opposed to the old two-port bridges of the
past. A "Firewall Appliance" does not route a packet,..it "NATs', or
"Translates" the packet. Yes NAT does require Layer3 routing as its
underlying "engine", but it is still considered a different technology that
simply runs on top of Layer3 Routing. This relationship between the two is
why a common*real* router can function as both a NAT Device or as a Router
by simply toggling the NAT functionality on or off and establishing or
de-establishing a "trusted" vs "untrusted" network using a LAT.

But Cable/DSL boxes are dedicated NAT Devices and they can not do anything
else. So to be accuarte they should be sold as "NAT Servers" or "Firewalls",
not as routers. I have already run into several people who thought you
could use one of these "so-called" routers as a regular LAN router on their
LAN due to the way people's concept of a router has been skewed and twisted
by the marketing terminology of these SOHO devices.
: are you planning to go to the MVP Mini-Summit?

I wasn't invited. I'm not an MVP, except on Singapore Airlines. (O;=
Click to expand...

Well, you never know, you may get that letter from MS one day. I wasn't
expecting it when I got it. My MVP is in "Proxy/ISA" which seems to be kind
of a branch or segment of the "Security" MVPs. Although personally I
consider myself more of just a "general networking" guy.
 
in message
:
: > : are you planning to go to the MVP Mini-Summit?
: >
: > I wasn't invited. I'm not an MVP, except on Singapore Airlines. (O;=
:
: Well, you never know, you may get that letter from MS one day. I wasn't
: expecting it when I got it. My MVP is in "Proxy/ISA" which seems to be
kind
: of a branch or segment of the "Security" MVPs. Although personally I
: consider myself more of just a "general networking" guy.

Oh well, if that happens it'll be totally unexpected. Having someone say,
"Thanks, that helped" is enough.

I like ISA but I'm not big on MSFT Proxy Server. Another one that needs to
be shot.

General Networking? How many stars? (O:= Are you kin to that guy on my
computer, General Error?

--
Roland Hall
/* This information is distributed in the hope that it will be useful, but
without any warranty; without even the implied warranty of merchantability
or fitness for a particular purpose. */
Online Support for IT Professionals -
http://support.microsoft.com/servicedesks/technet/default.asp?fr=0&sd=tech
How-to: Windows 2000 DNS:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;308201
FAQ W2K/2K3 DNS:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;291382
 
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