Re: IRB and DLSW+

From: Gerard Robinson (gerardrobinson@xxxxxxxxxxxxxx)
Date: Tue Jun 27 2000 - 14:43:50 GMT-3


   
   
           IP is always routed unless you issue the command 'no ip
   routing' or you run CRB so putting an interface into a bridge-group
   will not bridge IP unless you have specifically turned off IP routing
   by issuing the aforementioned command. If you do a 'sh int irb' you
   can see which protocols are bridged and which are routed. Once you
   turn on routing for a protocol and then put a layer 3 address on an
   interface then all traffic for that protocol is routed and not
   bridged. So on a interface with an IP address and ip routing enabled
   all IP traffic is always routed and non-routable traffic like
   NetBIOS/SNA is bridged to DLSW and then encapsulated to IP.
   
           One thing that confuses me is why all example configs for DLSW
   from a Token Ring interface are always using source-route bridging,
   you can use normal transparent bridging on Token Ring interface and it
   works fine so source-route bridging is not a necessity. I think it
   must be that source-route bridging is very popular in Token Ring
   environments and is the bridging of choice for Token Ring.
   
   
   ----- Original Message -----
   
   From: Earl Aboytes
   
   To: ccielab@groupstudy.com
   
   Sent: Monday, June 26, 2000 9:35 AM
   
   Subject: IRB and DLSW+
   
   Here is a question that I thought I had resolved until I started
   reading the doc CD
   
   Assumptions:
   
   When you turn on dlsw in a router you have to bridge from Ethernet to
   dlsw. When you turn on dlsw on a router you have to source-route
   bridge from token ring to dlsw.
   
   Question:
   
   Did you just ruin routing of IP over the Ethernet and Token if you put
   it a bridge group or turn on source route bridging?
   
   Possible answer:
   
   My guess is no. It seems that dlsw turns on IRB automatically. I
   thought this was the answer for both token and Ethernet until I read
   the following passage on the Doc CD.
   
   
   Integrated routing and bridging is supported for transparent bridging,
   but not for source-route bridging (SRB).
   
   
   So what is the real answer? Did I lose routing of IP on my token
   interface when I turned on SRB? I would guess that dlsw takes care of
   this. Any thoughts on this?
   
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   
   Earl Aboytes
   
   Senior Technical Conultant
   
   GTE Managed Solutions
   
   805-381-8817
   
   earl.aboytes@telops.gte.com
   
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   



This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:23:43 GMT-3