 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
And lo on Fri, 11 Jan 2008 13:20:56 -0000, scott <sco### [at] laptop com> did
spake, saying:
>> No, but the fact that it's looking at (and changing) IP headers does.
>
> Don't think my switch changes any IP headers, it just either routes them
> somewhere or doesn't based on a set of rules.
Am I the only one ammused by 'a switch isn't a router because it just
routes packets' implicit here? :-)
> I thought a switch just dealt with stuff in one network address space,
> eg you use it to simply provide enough sockets for everyone to connect
> into something else, and it just send unmodified packets to the right
> place. A router however connects two different networks together, and
> has things like port forwarding, NAT, modifying the IP headers etc.
>
> Or maybe I'm completely off track as I'm no expert, that's just based on
> my experience with working with things labelled as "routers" and
> "switches".
Cutting to the bone:
A hub takes input and fires it out of every port; a switch takes input and
routes/switches it to the correct port for the same subnet; a router
connects subnets together. If you want to know what to call the piece of
equipment you're using just check its capabilities up that list and stop
when they don't match.
So when you have a piece of equipment connecting the 'Internet' subnet to
your 'Home' subnet that's a router despite the fact it also connects all
your computers on the same subnet, which would just be a switch or hub on
its own.
IOW it doesn't matter if it inspects packets, reports QoS, checks MAC
addresses or sings "Daisy, Daisy" when there's a fault; thouse are just
added features.
--
Phil Cook
--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 11 Jan 2008 10:06:41 +0000, Invisible <voi### [at] devnull> wrote:
>These "switches" are actually *routers*. That's why they're so damn
>expensive - each one is a 24-port *router*!!
Which model are you getting?
BTW, just because a switch does layer 3 inspection (for QoS and such), does not make
it a router. It may still be directing the packets to the appropriate port based on
the MAC address (layer 2) and
not the IP address.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
>> These "switches" are actually *routers*. That's why they're so damn
>> expensive - each one is a 24-port *router*!!
>
> Which model are you getting?
Cisco Catalyst 3560.
> BTW, just because a switch does layer 3 inspection (for QoS and such), does not make
it a router. It may still be directing the packets to the appropriate port based on
the MAC address (layer 2) and
> not the IP address.
You can argue about the names. The point is it provides wildly more
functionallity than we actually need.
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 11 Jan 2008 15:07:55 +0000, Invisible <voi### [at] devnull> wrote:
>You can argue about the names.
There's no argument about the names. I won't let you call an apple an orange without
pointing out that it really is an apple (although it may have an orange hue to it).
>The point is it provides wildly more
>functionallity than we actually need.
Based on your description of your network, that sounds true. It's kind of like frying
an egg with a nuclear reactor. (Well not to that extreme, but you catch my drift.)
Have you asked them why they
opted for the more expensive Cisco units?
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
>> You can argue about the names.
>
> There's no argument about the names. I won't let you
> call an apple an orange without pointing out that it
> really is an apple (although it may have an orange hue to it).
My point is I'm less worried about names and more worried about what it
actually *does*. ;-)
>> The point is it provides wildly more
>> functionallity than we actually need.
>
> Based on your description of your network, that sounds true.
> It's kind of like frying an egg with a nuclear reactor.
> (Well not to that extreme, but you catch my drift.)
> Have you asked them why they opted for the more expensive Cisco units?
They want everybody to use the same brand and model of... well,
everything actually. And Cisco is undeniably the best brand on the market...
As for why the multiple submets... er... I have no idea.
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 11 Jan 2008 15:07:55 +0000, Invisible <voi### [at] devnull> wrote:
>Cisco Catalyst 3560.
I just watched the "Video Data Sheet" at
http://www.cisco.com/en/US/products/hw/switches/ps5528/ for the device. It's quite
interesting how the video features the Senior Product Manager speaking
English with a very heavy French accent, to the point that he is almost
incomprehensible. It's good that the video is subtitled.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Invisible wrote:
> Then it's not a switch, is it?
In most situations, a router is something that directs packets based on
an ISO level-3 address (i.e., an IP address) and a switch is something
that directs packets based on a level-2 address (i.e., a MAC address).
Nothing says a switch can't do active routing jobs.
--
Darren New / San Diego, CA, USA (PST)
It's not feature creep if you put it
at the end and adjust the release date.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 11 Jan 2008 11:45:50 +0000, Invisible wrote:
> A hub is little more than an amplifier. A switch contains actual control
> electronics. That much is true. However, a switch still does the same
> *job* as a hub - it just does it better. There still isn't anything that
> needs to be "configurated". [But, as I found out, these switches are
> actually routers.]
A switch limits the collision domain, which is good for performance but
bad for network monitoring tasks. Many of the Cisco switches of the last
several years (and other "smart" switches, for that matter) have
management interfaces that let you view traffic counters and other
diagnostic information to help you isolate problems. Not to mention port
mirroring (as Cisco calls it) to allow you to use your copy of Wireshark
to view all the traffic seen on another port on the switch for diagnostic
purposes.
Because the collision domain is restricted, there's also buffering
components and elements to eliminate collisions nearly completely (or
completely).
A lot of the newer switches on the market also include authentication
smarts, so only authorized devices can be plugged into the network.
802.11x authentication (I think is what is used) can be used against
directory service data stores as well, providing a high degree of
security in environments that need it.
What kind of switches are they? Some switches identify as being layer 3
switches (in the OSI model), but some newer ones will also do layer 4
switching, which also increases the complexity of the component. Many
times, a L4 switch can be thought of as a router, even though it really
isn't (a router connects one subnet to another).
Some switches also include smarts for VLANs, which limit the broadcast
domain as well as the collision domain limiting that a dumb switch will
do.
Jim
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 11 Jan 2008 12:54:23 +0000, Invisible wrote:
> No, but the fact that it's looking at (and changing) IP headers does.
Routers are not the only components that do that.
> Besides, the fact remains: We don't need this.
You may not think so, but maybe the folks at HQ have some ideas that they
haven't told you about. Or things like VOIP, which while you may not
need it there, can significantly reduce calling charges overseas. Think
Skype.
Jim
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 11 Jan 2008 13:41:26 +0000, Invisible wrote:
> The device I'm looking at is routing traffic between different IP
> networks, which requires looking not only at Ethernet headers but IP
> headers as well. That's a seperate level of complexity.
Doesn't reach the same level of complexity as a router, though. What
you're describing is a layer 4 switch, I believe.
Jim
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
