I must confess that my CCIE Lab preparation with regards to DLSw was probably a lot like most peoples - I got a good SLSw book a few days before my date and spent 10-12 hours learning "enough to be dangerous" I can't comment on the suitability of this approach, and even if I could, the fact is that I was having too many other problems in my Lab to where DLSw was the least of my worries. that said, if there were no token ring switch in the picture, I would have something like this:
TR_port----DLSW_Router-------Virtual_Ring-------DLSW_router------TR_port my DLSw config would include the source-bridge ring-group [virtual_ring # ] and the dlsw ring-list x rings [whatever rings are to receive dlsw traffic] my token ring interfaces would be configured with the source-bridge [ring_a] [bridge] [ring_b] numbers where ring_a is the ring to which the TR interface is attached and the bridge is somewhat arbitrary ( stop grinding your teeth, Priscilla! ;-> ) and ring_b is the virtual-ring number. But if I were to do it this way: DLSw_router----TR_port-------TR_Switch-------TR_port---DLSw_router then the virtual-ring is on the TR switch, isn't it? I.e. now the virtual ring is something configured on the switch, and to me that looks like the TrBRF number. Maybe I am just confusing my terminology here. If the two Tr ports were connected to a mau, they would both be on the same ring number, and the DLSw command source-bridge ring-group number would be that actual physical ring number. Is it time to go home yet? ;-> Chuck ""MADMAN"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I think you are close but here are my thoughts off the top of my > noodle, the source ring would be the TRCRF as you say. I think the > bridge number just needs to be the same on both routers and is not > associated with the BRF. lastly the target ring is the number you > choose via the source-ring bridge-group command on the router. > > FWIW > > Dave > > Chuck Larrieu wrote: > > > > for whatever reason, my mind has been ensnared with thoughts of the Cat > 3920 > > token ring switch and various implications. > > I want to run a couple of concepts through the list, just to check that my > > understanding is correct. > > > > So, because of the nature of token ring, one has to do some jiggering to do > > token ring switching. IBM or whomever, in their wisdom, came up with the > > following model: > > > > in general - token ring bridging works on the ringbridgering model > > > > port - into which plugs some physical token ring device, which may be a > > router, an end station, or a token ring shared media device like a mau. ( > > much the way one might plug ethernet hubs into switch ports ) A port can > > connect only to one TrCRF ( see next layer ) > > > > TrCRF - token ring concentrator ring function. This is the logical virtual > > ring. more than one physical port can connect to a TrCRF, which in turn can > > connect to only one TrBRF ( see next layer ) > > > > TrBRF - token ring bridge relay function. As implied by the name, the TrBRF > > bridges between the virtual rings. The TrBRF is also the "VLAN". therefore > > routing must occur between stations ultimately connected through different > > TrBRF's. > > > > This is what I am not sure about. Per the 3920 simulator I am using > > different BRF's can be on the same subnet. I don't have access to a real > > device to see if this is true in the real world. > > > > Also, there is a decent explaination of token ring vlans in the Kennedy > > Clark book Cisco Lan Switching. However, Clark seems to emphasize source > > route switching, and the advantages in terms of explorers, rather than > > straight ( if there is such a thing in token ring ) switching, and the > > advantages to end stations. > > > > One of the things I am getting around to in this post is DLSw over a token > > ring switch. DLSw is configured on a cisco router using bridging and a > > virtual ring which is created across a TCP network between peers. > > > > router ----virtual_ring------router > > | | > > TR_port TR_port > > > > with the configuration of the TR port using the source-bridge set of > > commands source-bridge source-ring-number bridge-number target-ring-number > > > > If I wanted to run DLSw across a 3920, then on my router ( whose token ring > > port is plugged into a 3920 ) I would use the source-bridge > > source-ring-number bridge-number target-ring-number comand. The source ring > > would be identical to the TrCRF ring, the bridge would be the TrBRF, and > the > > target ring would be the DLSw virtual ring, as confgured under DLSw. Is > that > > correct? > > > > Sorry if this is a bit disjointed. I'm working from home today and the > > family seem to think that if they are on vacation, so am I. > > > > Any thoughts would be appreciated. > > > > Chuck > -- > David Madland > Sr. Network Engineer > CCIE# 2016 > Qwest Communications Int. Inc. > [EMAIL PROTECTED] > 612-664-3367 > > "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=30582&t=30566 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
