Frank,
I had the same problem as you did with the concept before. I believe that
Sean and Chris are both talking about the same thing. RSM module is
essentiality a router that is design to route between VLANs instead of
networks.
Remember, there are many kinds of switches. (Ethernet, Token Ring, ATM)
Main purpose of VLANs is to limit broadcast (that's what most of us use it
for but there are other uses like security).
>From a design point of view and to keep it simple. At the access layer,
each switch will have one VLAN. At the distribute layer you would have
switches with RSP in it. It will function as the security, switching/routing
between the VLANs. At the core layer, you can have only switches. All
broadcast had been stop or change to unicast at the distribute layer. In a
WAN situation, those switches could be ATM.
If you have no broadcast in your network at all, you can do without the RSP
and the VLANs. I am not sure how such a network would work but Howard or
Priscilla can probability tell you.
I hope this helps. A really good book to read about switching is CCIE
Professional Development: Cisco LAN Switching.
Albert
-----Original Message-----
From: Frank Wells [mailto:[EMAIL PROTECTED]]
Sent: Friday, August 11, 2000 11:15 AM
To: [EMAIL PROTECTED]
Subject: RE: Switches !!!
What Sean implied here is you will always need a router to route between
VLAN's. I thought you could use a router (router on a stick)OR
a RSP. He claims that the initial route needs to be found by a router and
then the RSP can take over. I still have a problem with this concept
because I have read about networks consisting entirely of switches from
access layer up to the core layers, and switched across WAN's too!!!
>From: Chris Larson <[EMAIL PROTECTED]>
>To: 'Frank Wells' <[EMAIL PROTECTED]>, [EMAIL PROTECTED]
>Subject: RE: Switches !!!
>Date: Fri, 11 Aug 2000 14:04:36 -0400
>
>You will always need to have a router or a route processor to router
>between
>VLANS. At least with current technology. Layer 3 switching is really just
>being able to processes a route and then forward at switch or wire speeds.
>It still needs to process a route, and is routing between lan segments.
>
>
>In the second part I believe Sean is speaking about Netflow switching where
>the router determines how to route a source/destinatioon once, and once the
>switch learns how that packet was routed through the switch, the next time
>it recieves a similiar source/destination that normaly would require route
>processing it will just switch the packet to the appropriate port based on
>what it learned the last time without asking the router to process a route.
>
>
>
>-----Original Message-----
>From: Frank Wells [mailto:[EMAIL PROTECTED]]
>Sent: Friday, August 11, 2000 12:30 PM
>To: [EMAIL PROTECTED]
>Subject: RE: Switches !!!
>
>
>Hey Sean.
>This is regarding the following passage taken from the your previous reply
>to this thread:
>
>If C. If the destination and source node reside on ports assigned to
>different VLANs on the switch, the switch requires an external router to
>resolve the address and send the packet back to the switch. <*** If the
>switch contains an internal route processor, the external router needs to
>only resolve the first packet and then the internal route processor can
>finish the job from there. ***> (An external router needs to be used so
>that
>
>a routing protocol can be used to map the network topology to base it's
>routes.)
>
>The second sentence implies that there will always need to be at least one
>router in any switched network. Is this actually correct? I seem to
>remember reading that there are fully switched networks utilizing layer
>three switching as the routing mechanism. What I am getting at is I
>thought
>
>Route Switch Processors are layer three devices and fully capable of making
>their own routing decisions, in which case there would be no need for a
>router. Can you shed some more light please.
>
>Thanks a lot.
>
>
> >From: "Odom, Sean/SAC" <[EMAIL PROTECTED]>
> >Reply-To: "Odom, Sean/SAC" <[EMAIL PROTECTED]>
> >To: "'[EMAIL PROTECTED]'" <[EMAIL PROTECTED]>
> >CC: "'Raees Ahmed Shaikh'" <[EMAIL PROTECTED]>
> >Subject: RE: Switches !!!
> >Date: Fri, 11 Aug 2000 09:46:12 -0600
> >
> >a1. How are MAC addresses used on a switch: The MAC address of the
>switch,
> >depending on the interface being used, handle this in different ways.
>Some
> >Catalyst switches assign a global MAC address, some switches use a pool
>of
> >addresses assigning one to each interface(You can assign one manually),
>and
> >sometimes the MAC address can be a virtual MAC address when using HSRP on
> >mulitiple internal route processors such as the MSM, RSM, RSFC, NFFC,
> >NFFCII
> >or the MSFC. The switch is assigned an IP address and default gateway
> >which
> >allows you to telnet to the switch. On most switches you can also use
>the
> >your webrowser to access the switches configuration and make changes
>simply
> >by typing in the switches IP address.
> >
> >a2. If two nodes on the same switch want to communicate on the same
>switch:
> >(This question requires a long answer!)
> >
> >If: A. They are connected to the same port on the switch the switch does
> >nothing since the two nodes are in the same collision domain they will
>see
> >each others traffic.
> >
> >If B. They are in the same VLAN and reside on the same switch, the switch
> >learns the location of each node attached by reading the first frame
> >received and logging the source address and port of arrival in it's
>Content
> >Addressable Memory(CAM) table. When the switch receives another frame it
> >checks the CAM table and if it knows the port the destination node
>resides
> >on it forwards the frame directly to that port. If it does not know the
> >port, it broadcasts the frame to every port which are members of the same
> >VLAN with the exception to the port of arrival.
> >
> >If C. If the destination and source node reside on ports assigned to
> >different VLANs on the switch, the switch requires an external router to
> >resolve the address and send the packet back to the switch. If the
>switch
> >contains an internal route processor, the external router needs to only
> >resolve the first packet and then the internal route processor can finish
> >the job from there. (An external router needs to be used so that a
>routing
> >protocol can be used to map the network topology to base it's routes.)
> >
> >Hope this answers your questions.
> >
> >Sean Odom, CCNP, MCSE, CNX-EtherII, Author, Instructor
> >GlobalNet Training Solutions
> >[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
> >www.TheQuestForCertication.Com <http://www.TheQuestForCertication.Com>
> > -----Original Message-----
> >From: Raees Ahmed Shaikh [mailto:[EMAIL PROTECTED]]
> >Sent: August 08, 2000 11:50 PM
> >To: '[EMAIL PROTECTED]'
> >Subject: Switches !!!
> >
> >
> >
> >
> > If all the ports of the switches have mac addresses than
> >
> >q.1 If somebody telnets to swithes the actual physical communication
> >occurs
> >through which mac address.
> >q.2 If two pcs are connected to the same swithc, and they want to
> >communicate the real communication should go like this ( pc mac- switch
> >port mac - destination switch port mac - destination pc).
> >
> >Totally confused arp arp arp.
> >
> >Please Help.
> >
> >
> >Shaikh Raees Ahmed,
> >Microsoft Certified Systems Engineer,
> >Systems & Network,
> >IT Division.
> >
> >___________________________________
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