basic rsrb configuration and concepts.htm

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<p>The most commonly used encapsulation type, is TCP. This
encapsulation has greater overhead than direct and FST, both on
the network, where every RSRB packet gets encapsulated within a
full IP and TCP header, and in the routers, where there is
additional processor overhead for maintaining a TCP session for
every remote-peer required. The advantage of TCP encapsulation is
the reliable delivery of packets, which lessens the recovery
responsibility of end stations in the case of a lost or corrupted
packet. </p>

<p>TCP configuration is very similar to FST configuration.
Instead of a special command to configure the peername, the IP
address representing the local router is treated exactly the same
as a remote peer. Here is a TCP peering configuration equivalent
to the previously presented FST configuration: </p>

<p><b>ROUTER A:</b> </p>

<pre>
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 tcp 1.1.1.1
  source-bridge remote-peer 4095 tcp 1.2.2.2
  source-bridge remote-peer 4095 tcp 1.3.3.3
</pre>

<pre>  interface serial 0 
  ip address 1.255.1.1 255.255.0.0 </pre>

<pre>  interface tokenring 0 
  ip address 1.1.1.1 255.255.0.0 
  source-bridge 1 1 4095 <i>
   source-bridge spanning</i> </pre>

<pre>  router rip 
  network 1.0.0.0 </pre>

<p><b>ROUTER B:</b> </p>

<pre>
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 tcp 1.2.2.2
  source-bridge remote-peer 4095 tcp 1.1.1.1
  source-bridge remote-peer 4095 tcp 1.3.3.3
</pre>

<pre>  interface serial 0 
  ip address 1.255.1.2 255.255.0.0 </pre>

<pre>  interface fddi 0 
  ip address 1.254.1.2 255.255.0.0 </pre>

<pre>  interface tokenring 0 
  ip address 1.2.2.2 255.255.0.0 
  source-bridge 2 1 4095 
<i>   source-bridge spanning</i> </pre>

<pre>  router rip 
  network 1.0.0.0 </pre>

<p><b>ROUTER C:</b> </p>

<pre>
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 tcp 1.3.3.3
  source-bridge remote-peer 4095 tcp 1.1.1.1
  source-bridge remote-peer 4095 tcp 1.2.2.2
</pre>

<pre>  interface fddi 0 
  ip address 1.254.1.1 255.255.0.0 </pre>

<pre>  interface tokenring 0 
  ip address 1.3.3.3 255.255.0.0 
  source-bridge 3 1 4095 <i>
   source-bridge spanning</i> </pre>

<pre>  interface tokenring 1 
  source-bridge 4 1 4095 <i>
   source-bridge spanning</i> </pre>

<pre>  router rip 
  network 1.0.0.0 </pre>

<p>NOTE: In this configuration, the local remote-peer statement
is always the first of the configured remote-peers. This makes it
easier to understand for troubleshooting. </p>

<h2>Configuration Example - Mixed Encapsulations</h2>

<p>It is alright to mix encapsulation types within a ring group,
but there are some simple rules to be follow. </p>

<ul>
    <li>　</li>
    <li>Any router using FST peering must have an FST peername.
        The FST peername is the IP address of one of the
        interfaces. Use of an address defined for a loopback
        interface is permissable. </li>
    <li>Any router using TCP peering must have a local
        remote-peer statement. The source bridge remote peername
        is the IP address of one of the interfaces. Use of an
        address defined for a loopback interface is permissible. </li>
    <li>When peering two routers, only one encapsulation type can
        be used. You cannot have a TCP peer statement from A to
        B, and an FST peer statement from B back to A. Similarly,
        you cannot peer from A to B with more than one
        encapsulation type. </li>
</ul>

<p>The example below shows all three encapsulation types within
the same ring group. Routers A and B are peered using direct
encapsulation, routers A and C use TCP encapsulation, and routers
B and C use FST encapsulation. </p>

<p><b>ROUTER A:</b> </p>

<pre>
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 tcp 1.1.1.1
  source-bridge remote-peer 4095 tcp 1.3.3.3
  source-bridge remote-peer 4095 interface serial 0
</pre>

<pre>  interface serial 0 
  ip address 1.255.1.1 255.255.0.0 </pre>

<pre>  interface tokenring 0 
  ip address 1.1.1.1 255.255.0.0 
  source-bridge 1 1 4095 <i>
   source-bridge spanning</i> </pre>

<pre>  router rip 
  network 1.0.0.0 </pre>

<p><b>ROUTER B:</b> </p>

<pre>
  source-bridge fst-peername 1.2.2.2
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 interface serial 0
  source-bridge remote-peer 4095 fst 1.3.3.3
</pre>

<pre>  interface serial 0 
  ip address 1.255.1.2 255.255.0.0 </pre>

<pre>  interface fddi 0 
  ip address 1.254.1.2 255.255.0.0 </pre>

<pre>  interface tokenring 0 
  ip address 1.2.2.2 255.255.0.0 
  source-bridge 2 1 4095 <i>
   source-bridge spanning</i> </pre>

<pre>  router rip 
  network 1.0.0.0 </pre>

<p><b>ROUTER C:</b> </p>

<pre>
  source-bridge fst-peername 1.3.3.3
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 fst 1.2.2.2
  source-bridge remote-peer 4095 tcp 1.3.3.3
  source-bridge remote-peer 4095 tcp 1.1.1.1
</pre>

<pre>  interface fddi 0 
  ip address 1.254.1.1 255.255.0.0 </pre>

<pre>  interface tokenring 0 
  ip address 1.3.3.3 255.255.0.0 
  source-bridge 3 1 4095 
<i>   source-bridge spanning</i> </pre>

<pre>  interface tokenring 1 
  source-bridge 4 1 4095 <i>
   source-bridge spanning</i> </pre>

<pre>  router rip 
  network 1.0.0.0 </pre>

<h2>Configuration Example - Indirect Bridging</h2>

<p>So far we have only dealt with situations with one ring-group,
but there are times when we might want to bridge multiple
ring-groups together. There is no command which directly bridges
two ring-groups together, but we can accomplish this with
indirect bridging. Through the use of multiple token ring
interfaces on the same segment, two or more ring groups can be
indirectly bridged together. Here's an example: </p>

<pre>
                              Token
                              Ring 2
                            T0|    |T1
                              |    |
              ----------S0  ----------S1  ----------
          T0  |        |--- |        |--- |        | T0
    Token-----|Router A| /  |Router B| /  |Router C|-----Token
    Ring 1    |        | ---|        | ---|        |     Ring 3
              ----------  S0----------  S0----------
</pre>

<p><b>ROUTER A:</b> </p>

<pre>
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 interface serial 0
</pre>

<pre>  interface serial 0 
  encapsulation hdlc </pre>

<pre>  interface tokenring 0 
  source-bridge 1 1 4095 <i>
   source-bridge spanning</i> </pre>

<p><b>ROUTER B:</b> </p>

<pre>
  source-bridge ring-group 4095
  source-bridge remote-peer 4095 interface serial 0
  source-bridge ring-group 4094
  source-bridge remote-peer 4094 interface serial 1
</pre>

<pre>  interface serial 0 
  encapsulation hdlc </pre>

<pre>  interface serial 1 
  encapsulation hdlc </pre>

<pre>  interface tokenring 0 
  source-bridge 2 1 4095 <i>
   source-bridge spanning</i> </pre>

<pre>  interface tokenring 1 
  source-bridge 2 1 4094 
<i>   source-bridge spanning</i> </pre>

<p><b>ROUTER C:</b> </p>

<pre>
  source-bridge ring-group 4094
  source-bridge remote-peer 4094 interface serial 0
</pre>

<pre>  interface serial 0 
  encapsulation hdlc </pre>

<pre>  interface tokenring 0 
  source-bridge 3 1 4094 <i>
   source-bridge spanning</i> </pre>

<p>NOTES: </p>

<ul>
    <li>In the above configuration, physical ring 2 (connected to
        the two token ring interfaces of Router B) is being used
        for indirect bridging of ring groups 4095 and 4094. This
        ring can be used by other devices as well, but be aware
        that there may be a heavy load on this ring as it is
        handling broadcast traffic from both ring groups. </li>
    <li>Because of the indirect bridging, stations on the token
        ring off of Router A can communicate with stations on the
        token ring off of Router C, even though they are not
        peered together. If the indirect bridging commands were
        removed from Router B, this connectivity would be lost. </li>
    <li>Indirect bridging is a mechanism for joining two existing
        ring groups without having to reconfigure all of the
        routers within one of the groups. It's more of a patch
        than a design feature, and it is not regarded as a good
        design practice. When designing a network from the start,
        multiple ring-groups joined in this manner should not be
        designed intothe same RSRB network. </li>
</ul>

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