Chapter 19 Configuring Source-Route Bridging

Objectives Upon completion of this chapter, you will be able to perform the following tasks: Describe the basic functions of source-route bridging (SRB) Configure source-route bridging Configure source-route transparent bridging Configure source-route translational bridging Verify source-route bridging operation

Source-Route Bridging

Source-Route Bridging Overview  Explorer packets discover route destination X Y Token Ring 501 Token Ring 502 Token Ring 505 Token Ring 500 Bridge 2 Bridge 4Bridge 1 Bridge 3

Source-Route Bridging Operation  Source chooses path to destination X Y Token Ring 501 Token Ring 502 Token Ring 505 Token Ring 500 Bridge 2 Bridge 4Bridge 1 Bridge RIF X Y RIF X Y

Routing Information Indicator  Indicates routing information is contained in the frame  Most significant bit of the source address  Set by the source Destination SourceRIFData FCS Address RII

Routing information Field RCRD …. RIF Routing Control Type 0 X X 1 0 X 1 1 X Specific route All rings, all routes Spanning route Length Direction Largest Route Description Ring Number Bridge Number Contains control and path information

SRB Configuration Router (config-if) # source-bridge local-ring bridge-number target-ring  Specifies the local bridge connection Router (config-if) # Source-bridge spanning Actives automatic spanning for an interface

SRB Configuration (cont.) Token Ring 500 Token Ring 501 Bridge 1 To0To1 Two Local Rings interface tokenring 0 source-bridge source-bridge spanning interface tokenring 1 source-bridge source-bridge spanning interface tokenring 0 source-bridge source-bridge spanning interface tokenring 1 source-bridge source-bridge spanning

SRB Automatic Spanning Tree Configuration Token Ring Token Ring Token Ring 500 Token Ring 501 Token Ring Y X bridge 7 protocol ibm ! interface tokenring 0 source-bridge source bridge spanning 7 ! Interface tokenring 1 source-bridge source-bridge spanning 7 bridge 7 protocol ibm ! interface tokenring 0 source-bridge source bridge spanning 7 ! Interface tokenring 1 source-bridge source-bridge spanning 7

Multiport Configuration Token Ring 500 Bridge 1 Token Ring 501 Virtual Ring 10 Token Ring 502 Router (config) # source-bridge ring-group ring-group-number  Creates a virtual ring

Multiport Configuration Example Token Ring 500 Token Ring 501 Bridge # 1 To0To1 source-bridge ring-group 10 interface tokenring 0 source-bridge source-bridge spanning interface tokenring 1 source-bridge source-bridge spanning source-bridge ring-group 10 interface tokenring 0 source-bridge source-bridge spanning interface tokenring 1 source-bridge source-bridge spanning Token Ring 502 To2

Proxy Explorer Token Ring Token Ring Token Ring Token Ring B A Z Router (config-if) # source-bridge proxy-explorer  Enables the interface to send specifically frames to the destination

multiring Command SRB Token Ring 32 Token Ring 31 Source-Route Bridge Network Routed Network Routed Network Router (config-if) # multiring { keyword [ all-routes | spanning ] | all | other }  Enables the collection and use of RIF information

Multiring Configuration Example SRB Token Ring 32 Token Ring 31 Source-Route Bridge Network Routed Network Routed Network interface tokenring 0 multiring ip ip address ipx network 33

Source-Route Transparent Bridging

Source-Route Transparent Bridging SRB Token Ring TB D Token Ring C Transparent bridging and source-route bridging traffic handled appropriately

SRT Operation Token Ring Token Ring RIF Has RIF ? Transparent Bridging ModuleSource-Route Bridging Module YES NO

SRT Configuration Example 500 SRT 501 C B A D Transparent Source Route bridge 4 protocol ieee source-bridge ring-group 10 ! interface ethernet 0 bridge-group 4 interface ethernet 1 bridge-group 4 interface tokenring 0 bridge-group 4 source-bridge source-bridge spanning interface tokenring 1 bridge-group 4 source-bridge source-bridge spanning

Source-Route Translational Bridging

Bridging Different Media with SR/TLB SRT Token Ring TB SRB Domain TB Domain Source-route translational bridging (SR/TLB) translates between transparent and SRB bridging SR/TLB handles: - MTU - RIF - Bit ordering - MAC address in data

B Source-Route Translational Bridging Token Ring C Pseudo Ring “Virtual” Bridge Group TB sees SRT as “Virtual” bridge group SRT sees TB pseudo ring RIF information added or removed

SR/TLB configuration Router (config-if) # Source-bridge transparent ring-group pseudo-ring bridge-number tb-group [ oui ]  Enables bridging between the transparent bridge configuration and the source-route bridge configuration

SR/TLB Configuration Example 500 P.R. 13 Bridge 4 protocol ieee source-bridge ring-group 10 source-bridge transparent ! Interface ethernet 0 bridge-group 4 interface ethernet 1 bridge-group 4 interface tokenring 0 source-bridge source-bridge spanninng interface tokenring 1 source-bridge source-bridge spanning Bridge 4 protocol ieee source-bridge ring-group 10 source-bridge transparent ! Interface ethernet 0 bridge-group 4 interface ethernet 1 bridge-group 4 interface tokenring 0 source-bridge source-bridge spanninng interface tokenring 1 source-bridge source-bridge spanning

Verifying Source- Route Bridging Operation

Verifying SRB Operation Router# show source-bridge Local Interfaces: max receive transmit srn bn trn rpsnhpcnt:bytes cnt:bytes drops TR * * 7 39: :62923 Ring Group 10: This peer: TCP Maximum output TCP queue length, per peer: 100 Peers:State lvpkts_rxpkts_txexpl_gndrops TCP TCP TCP open2* Rings: nb: 1 rn:5 local ma: b TokenRing0fwd:18 nb: 1 rn:2 remote ma: TCP fwd:36 Explorers: input output spanning all-ringstotalspanning all-ringstotal TR Router# Router# show source-bridge Local Interfaces: max receive transmit srn bn trn rpsnhpcnt:bytes cnt:bytes drops TR * * 7 39: :62923 Ring Group 10: This peer: TCP Maximum output TCP queue length, per peer: 100 Peers:State lvpkts_rxpkts_txexpl_gndrops TCP TCP TCP open2* Rings: nb: 1 rn:5 local ma: b TokenRing0fwd:18 nb: 1 rn:2 remote ma: TCP fwd:36 Explorers: input output spanning all-ringstotalspanning all-ringstotal TR Router#

Verifying SRB Operation (cont.) Router# show source-bridge Codes: * interface, - static, + remote Hardware Addr How Idle(min)Routing information Field 5c rg b0 5a tr0308b ff0 5b tr c00tr0* c00tr1* a8.4800tr rg ff0 Router# Router# show source-bridge Codes: * interface, - static, + remote Hardware Addr How Idle(min)Routing information Field 5c rg b0 5a tr0308b ff0 5b tr c00tr0* c00tr1* a8.4800tr rg ff0 Router#

Summary Transparent bridging is predominantly used in Ethernet environments Spanning-tree algorithm eliminates loops IRB is used in the following situations: To migrate a bridged network to a routed network To connect a remote site that does not have routing capabilities To conserve IP, IPX, and Apple Talk addresses To increase performances by keeping local bridged traffic local