|
Posted by on February 28, 2006, 5:06 am
If you were Registered and logged in, you could reply and use other advanced thread options
A brouter is said to bridge non routable prtocols. But aren't non
routable protocols still Layer 3? I guess it's not routing 'cos it
doesn't involve a routing table. Functionally I suppose it's bridging.
So I guess it's bridging at layer 3?
so a brouter does either bridging at layer 3 or routing at layer 3 -
depending on the protocol.
I had never heard of bridging at layer 3.
am I right?
I know brouter is considered by some to be not such a serious term. But
it does bring up that OSI terminology question.
|
 
| |
Posted by glen herrmannsfeldt on February 28, 2006, 11:58 am
If you were Registered and logged in, you could reply and use other advanced thread options
q_q_anonymous@yahoo.co.uk wrote:
> A brouter is said to bridge non routable prtocols. But aren't non
> routable protocols still Layer 3? I guess it's not routing 'cos it
> doesn't involve a routing table. Functionally I suppose it's bridging.
> So I guess it's bridging at layer 3?
Well, Appletalk has a similar layer structure to TCP/IP, including
the ability to be routed. Some IP routers will bridge Appletalk,
such that the IP network is divided into subnets, but the Appletalk
network is one large net.
There are also non-routable protocols, which pretty much don't
have a layer 3, so bridging is the only way.
-- glen
|
|
Posted by Walter Roberson on February 28, 2006, 12:31 pm
If you were Registered and logged in, you could reply and use other advanced thread options
>A brouter is said to bridge non routable prtocols. But aren't non
>routable protocols still Layer 3?
Not usually. For example, classic IPX does not involve IP addresses.
There are a number of short-range protocols with no IP addressing.
For example, Spanning Tree, CDP, BPDUs; the Appletalk that the previous
poster mentioned.
|
|
Posted by snertking on February 28, 2006, 1:27 pm
If you were Registered and logged in, you could reply and use other advanced thread options
Walter Roberson wrote:
>
>
>>A brouter is said to bridge non routable prtocols. But aren't non
>>routable protocols still Layer 3?
>
>
> Not usually. For example, classic IPX does not involve IP addresses.
I'm wondering if you just misunderstood his question,Or I misundertand
your answer, since your answers are usually pretty dead on. You seem to
be implying that a protocol is not layer 3 if it does not use IP addresses.
IPX uses no IP address, but it is still a layer 3 protocol. It does have
IPX network and station addresses. Even tho the station address and the
MAC address are one in the same, IPX is still a Layer 3 protocol.
And IPX *IS* a *routable* layer 3 protocol. IPX routers have been around
for over 20 years now. In fact, any netware 2.x, 3.x or 4.x box that has
NIC's attaching it to more than one network will act as an IPX router by
defualt,a nd will send out IPX RIP packets once per minute. You have to
specifically turn it off. And of course most major routers will route it
as well. Bay/RS routers I know support it. <G>
>
> There are a number of short-range protocols with no IP addressing.
> For example, Spanning Tree, CDP, BPDUs; the Appletalk that the previous
> poster mentioned.
Just beasue something does not use IP addresses, or is non-routable,
does not mean it is not layer 3. Spanning Tree and it's BPDU's, as well
as GARP, etc, I would argue are not layer 3 but layer 2, since they
carry info specifically for layer 2 use. Appletalk I would argue IS
layer 3.
|
|
Posted by Walter Roberson on February 28, 2006, 8:39 pm
If you were Registered and logged in, you could reply and use other advanced thread options
>Walter Roberson wrote:
>>
>>>A brouter is said to bridge non routable prtocols. But aren't non
>>>routable protocols still Layer 3?
>> Not usually. For example, classic IPX does not involve IP addresses.
>I'm wondering if you just misunderstood his question,Or I misundertand
>your answer, since your answers are usually pretty dead on. You seem to
>be implying that a protocol is not layer 3 if it does not use IP addresses.
Yeh, I've gotten so accustomed to thinking of "router" as meaning
"IP router".
|
| Similar Threads | Posted | | IP layer and layer 2 IGMP Snooping | June 7, 2008, 1:28 am |
| Ethernet bridging questions | May 7, 2006, 12:24 pm |
| VLAN operation in Transparent bridging | July 24, 2005, 11:50 pm |
| Bridging VLANs on an HP ProCurve 2626 | August 31, 2005, 7:27 pm |
| 802.3ad and multiple mac addresses | June 4, 2007, 2:25 pm |
| duplicate MAC addresses | November 19, 2007, 6:02 pm |
| Different treatment for registered and unregistered MAC addresses | May 18, 2006, 11:06 pm |
| MAC addresses in router vs Access Point | May 1, 2008, 5:19 am |
| Layer 2 'Ping' | August 15, 2005, 2:22 pm |
| want to ana;yze the data in MAC layer. | January 6, 2006, 12:52 am |
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML site map