router contains a built-in switch versus router without a built-in switch

What's the differences between

router contains a built-in switch
and
router without a built-in switch??

Some routers even have built-in firewall.

I saw many routers in the market has built-in switch, but I don't know
why, and what's the advantages?

please advise. thanks!!

 

The combination might be cheaper than the two parts separately.
And then it's only one thing to plug in.

It's like stereo equipment. You can buy a receiver, or you can
buy separate amplifier and tuner and connect them together.

 

A router with a built-in switch works on the same principles as a standalone
switch. A router with a built in switch can be configured to just be a
switch and not a router by disabling the DHCP server on the router and then
it's just a standalone switch.

http://www.homenethelp.com/web/explain/about-hubs-and-switches.asp

I don't know about routers without a built-in switch.

Some routers use a packet filter FW solution like SPI some don't and some
routers use more than SPI a more powerful packet filter.

Most NAT routers for home usage fall into the category of the link below.

http://www.homenethelp.com/web/explain/about-NAT.asp

About firewalls

http://www.more.net/technical/netserv/tcpip/firewalls/

What does a computer, router or appliance running a network/Internet FW do?

http://www.firewall-software.com/firewall_faqs/what_does_firewall_do.html

see link above about hubs and switches

Duane

 

From: "Duane Arnold" <>

|
|
| A router with a built-in switch works on the same principles as a standalone
| switch. A router with a built in switch can be configured to just be a
| switch and not a router by disabling the DHCP server on the router and then
| it's just a standalone switch.
|
| http://www.homenethelp.com/web/explain/about-hubs-and-switches.asp
|
| I don't know about routers without a built-in switch.
||
| Some routers use a packet filter FW solution like SPI some don't and some
| routers use more than SPI a more powerful packet filter.
|
| Most NAT routers for home usage fall into the category of the link below.
|
| http://www.homenethelp.com/web/explain/about-NAT.asp
|
| About firewalls
|
| http://www.more.net/technical/netserv/tcpip/firewalls/
|
| What does a computer, router or appliance running a network/Internet FW do?
|
| http://www.firewall-software.com/firewall_faqs/what_does_firewall_do.html
||
| see link above about hubs and switches
|
| Duane
|

Duane:

Disabling DHCP on a Router with an E-Switch is often insufficient. uPnP would also have to
be disabled. There have been posts about this here, in dcom.modems.cable and dcom.xdsl.
Disabling the Router part will depend upon the vendor and model Router+E-switch.

One last point. SOHO Router's with built-in E-switches tend to have high switching
latencies. Thus their cheap price. This may or may not be a problem in a SOHO environment.
For those that need excellent transfer rates between LAN nodes, they may choose to get a
Router without an E-switch and get a managed E-switch from; Foundry, Nortel, 3Com, CISCO,
etc.

 

OK, I'll go with the uPuP thing, but most of the time that's disabled by
default is it not? It's been awhile since I last looked at a router for home
usage.

But for the average home user network where a router was converted into a
switch to plug into a gateway router of FW appliance, I don't think it's
much of a concern. I did that with the Linksys BEFW11S4 v1 router and for
wired or wireless machines using it as a switch, I didn't notice anything.
It was business as usual.

Duane

 

From: "Duane Arnold" <>

|
|>>
|>> A router with a built-in switch works on the same principles as a|>> switch. A router with a built in switch can be configured to just be a
|>> switch and not a router by disabling the DHCP server on the router and|>> it's just a standalone switch.
|>>
|>> http://www.homenethelp.com/web/explain/about-hubs-and-switches.asp
|>>
|>> I don't know about routers without a built-in switch.
|>>|>>
|>> Some routers use a packet filter FW solution like SPI some don't and|>> routers use more than SPI a more powerful packet filter.
|>>
|>> Most NAT routers for home usage fall into the category of the link|>>
|>> http://www.homenethelp.com/web/explain/about-NAT.asp
|>>
|>> About firewalls
|>>
|>> http://www.more.net/technical/netserv/tcpip/firewalls/
|>>
|>> What does a computer, router or appliance running a network/Internet FW|>>
|>> see link above about hubs and switches
|>>
|>> Duane
|>>|
| OK, I'll go with the uPuP thing, but most of the time that's disabled by
| default is it not? It's been awhile since I last looked at a router for home
| usage.
||
| But for the average home user network where a router was converted into a
| switch to plug into a gateway router of FW appliance, I don't think it's
| much of a concern. I did that with the Linksys BEFW11S4 v1 router and for
| wired or wireless machines using it as a switch, I didn't notice anything.
| It was business as usual.
|
| Duane
|

Duane:

I can't speak for all models of all vendors but, uPnP does come disabled on Linksys.

You are right, the avg. user won't see the latency. However, I have seen it when Ghosting
across a BEFSR81 so I ran some tests with like equipment in 100Mb/s Full-Duplex . When I
used an Intel (discontinued) managed E-switch I got much higher transfer rates than with the
BEFSR81. This translated to Ghosting across the wire took much more time to complete on the
BEFSR81. Unlike the BEFSR41, the BEFSR81 supports QoS and is intended for the business
user.

 

If I only want to connect to 3 PC in a LAN, the router has 4 ethernet
ports and it can do the job. If I want to connect more than 4 PC, then
I need a switch. This is the scenario of two parts separately.

I still don't understand because router with built-in switch has 4
ports also, how does it function as the combination of router and
switch together?

Here's different types of routers I looked at:

http://www.linksys.com/servlet/Sate...622279&pagename=Linksys/Common/VisitorWrapper

BEFSR41 EtherFast® Cable/DSL Router with 4-Port Switch V4.0 (4 ports)
BEFSR11 EtherFast® Cable/DSL Router (1 port)
BEFSR81 EtherFast® Cable/DSL Router with 8-Port Switch V3.0 (8 ports)

Another question, if the router has more than 1 port, then it must be
router with built-in switch. Is that correct assumption? Because the
traditional broadband router should only has 1 port?


please advise more... thanks!!

 

A router is doing packet forwarding in a special way in layer 3, while
a switch is doing frame forwarding in layer 2, see:

http://en.wikipedia.org/wiki/Router
http://en.wikipedia.org/wiki/Network_switch
http://en.wikipedia.org/wiki/OSI_model#Description_of_layers

No. A router at least has two network interfaces, because it's a
multi-homed host.

Yours,
VB.

 

in essence, its switch has 5 ports -- the fifth one hooks (internally)
to the router -- but they say it has 4 ports because those are the
external ones you can see

I had one of these. I wasn't happy with it. I suspect I wouldn't be
happy with the others, either.

yes (theoretically it could be a hub rather than a switch, but I doubt
anybody does that)

Because the

 

In the context, I think he meant 1 port on the LAN side.

 

From: "CJT" <>

< snip >

|
| yes (theoretically it could be a hub rather than a switch, but I doubt
| anybody does that)
|

< snip >

An Ethernet switch can NOT be a hub. Hubs only re-time signals. Hubs are basically
multi-port repeaters. Switches have active electronics to decide what MAC address packet
goes to what port and have a cache to memorize MAC addresses. On an E-switch, each port is
a collision domain. On a hub all ports are on the same collision domain. Therefore a
E-switch can not be a hub and vice versa. This is not theory, it is a fact.

As for the Linksys Routers they are all good. Albeit, I have yet to install a BEFSR41 v4.0

You had one. I have installed many !

I have installed numerous BEFSR41 v1, v2 and v3 Routers. No problems with any.
I am presently using a BEFSR81, a business class Router that support QoS. I have installed
all v1, v2 and v3 but just nearly as many as the BEFSR41 models.

The BEFSR11 is a waste unless one already owns or plans to own a managed Ethernet switch.

 

From: <>

|
| If I only want to connect to 3 PC in a LAN, the router has 4 ethernet
| ports and it can do the job. If I want to connect more than 4 PC, then
| I need a switch. This is the scenario of two parts separately.
|
| I still don't understand because router with built-in switch has 4
| ports also, how does it function as the combination of router and
| switch together?
|
| Here's different types of routers I looked at:
|
|
http://www.linksys.com/servlet/Sate...622279&pagename=Linksys/Common/VisitorWrapper
|
| BEFSR41 EtherFast® Cable/DSL Router with 4-Port Switch V4.0 (4 ports)
| BEFSR11 EtherFast® Cable/DSL Router (1 port)
| BEFSR81 EtherFast® Cable/DSL Router with 8-Port Switch V3.0 (8 ports)
|
| Another question, if the router has more than 1 port, then it must be
| router with built-in switch. Is that correct assumption? Because the
| traditional broadband router should only has 1 port?
|
| please advise more... thanks!!


Get the Linksys BEFSR41. It will allow you to connect four computers (or any TCP/IP
Ethernet devices such as a Print Server or a game box [ XBox, Playstation/2, etc.]) If you
plan on 5 or more computers than you can gert the BEFSR81.

You said "...how does it function as the combination of router and switch together? "

Think of the device as a Black Box. On the input side (WAN) it connects to an Internet IP
address. On the output side (LAN) it fans out to four connections. Inside that Black Box,
the device uses Network Address Translation (NAT) to take a WAN IP address (i.e;
71.254.72.3) and based upon the requests made by a PC on the LAN side will translate the IP
address to a Private Address such as 192.168.1.100.

All you have to know is that the device uses NAT to convert any of the addresses in the
following range (192.168.1.2 ~ 192.168.1.254) to the address obtained from the Internet
side. That's the NAT Router part. On the LAN side you can connect up to 253 computers.
This is obtained by chainingg hubs or Ethernet switches to the LAN side of the Router. The
BEFSR81 already supplies you with 8 ports for up to 8 computers. The BEFSR41 already
supplies you with 4 ports for up to 4 computers. However if you chain an Ethernet switch
(or hub but switches are preferred) than you can multiply the number of computers.

For example; Using the BEFSR41 and a 12-port Ethernet switch that has 1 upload port and 12
usable ports.
Three computers would connect to the BEFSR41. The Ethernet switch's upload port would be
connected to the fourth port on the BEFSR41. Thus with this combination, you can have up to
15 Ethernet devices using the Router.

 

wrote in

The links below explain connecting two Linksys routers together. It
doesn't matter which ones or if it's wired or a wireless router or any
brand name of routers for home usage like D-link, Netgear, Belkin and
whatever.

The long version

http://linksys.custhelp.com/cgi-bin/linksys.cfg/php/enduser/std_adp.php?
p_faqid=358&p_created=1084209764
&p_sid=FJfGf8Dh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX
3Jvd19jbnQ9MjM1JnBfcHJvZHM9MSwwJnBfY2F0cz0mcF9wdj0xLjE7Mi51MCZwX2N2PSZwX3
NlYXJjaF90eXBlPWFuc3dlcnMuc2VhcmNoX25sJnBfc2NmX2xhbmc9MSZwX3BhZ2U9MSZwX3N
lYXJjaF90ZXh0PXdpcmVsZXNzIHRvIHdpcmVk&p_li=&p_topview=1

The short version

http://tinyurl.com/9nvq7


You disable the DHCP server on the router, then it's no longer a router
it's a switch. It has the same functionality as if you went out and
brought a dedicated *switch* box and plugged it into the gateway router.

Even when the router is in router mode, it's using the built-in switch
technology for overall speed and performance of the router that the
router wouldn't have without the *switch* technology.

AGAIN

http://www.homenethelp.com/web/explain/about-hubs-and-switches.asp

Duane

 

That's like saying red can't be green. I didn't say a hub could be a
switch. I said a hub could be combined with a router, just as a switch
can be combined with a router. But I doubt anybody does.

Hubs only re-time signals. Hubs are basically

 

No, if you disable the router function (or just don't connect the WAN
link), then it's no longer a router. It can still function as a DHCP
server without being a router.

If you disable the DHCP server, then it's no longer a DHCP server (yet
another function built into the same box).

It has the same functionality as if you went out and

 

David H. Lipman wrote:

I suppose YMMV. I had problems with mine. This was when they first
came out, and the firmware was pretty unstable (and, IMHO, buggy).

.... or an unmanaged switch.

 

Well of course that's a given that you connect it to a LAN port on the
gateway router and DHCP is disabled on the second router that it is just
a switch. I don't recall any standalone *switches* that have DHCP.

And what your talking about above would be a double NAT-ed solution if
setup properly. I have never used a double NAT-ed solution but I think
that's what it is or could possibly be configured into but I could be
wrong.

Duane

 

From: "CJT" <>

|>> yes (theoretically it could be a hub rather than a switch, but I doubt
|>> anybody does that)
|>>|
| That's like saying red can't be green. I didn't say a hub could be a
| switch. I said a hub could be combined with a router, just as a switch
| can be combined with a router. But I doubt anybody does.

That's not what you said.. What you said is above < snip> and that is what I responded to.
Now if you meant something else, your wording made it come out differently.

 

Apparently I was imprecise, leaving the antecedent to "it" dangling and
unclear. Sorry.

 

These days all home broadband routers contain a built-in switch. Now
whether they are good-quality switches vs. standalone switches is a
matter of debate.

In the olden days you had home routers that only had one port for the
WAN side, and one port for the LAN side, and nothing else. That meant
that if you wanted to connect multiple computers to that LAN side, then
you had to buy a seperate hub or switch. I had one of those types of
routers, it was an old Linksys. I had to connect the LAN port to a hub,
and then I could connect computers to the hub.

Now, I hope you know what the difference is between a hub and a switch.
If not, then a switch is just a more sophisticated suped-up hub. Whereas
hubs had a lot of collisions between packets as multiple computers tried
to access the Ethernet simultaneously, the switch took the hub concept
and made it a much more managed experience. It's sort of like the
difference between a road with traffic lights and a road without.

Actually, all home routers have a built-in firewall. It's a natural
feature that emerges from how they work. They can't help but also act as
firewalls. They use a feature called NAT (natural address translation)
which means that they give all computers in the LAN these special fake
IP addresses which can't be seen on the Internet, only the router's own
WAN IP address can be seen -- natural firewall.

Avoid having to pay for an additional network component, if everything
is built in. Cheaper to package it all together.

Yousuf Khan