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This chapter describes the Source Route (SR) Service parameters for operating source route bridging and end system source routing. When configuring parallel bridges, 3Com recommends that you configure both bridges in the same bridge mode, source route (SR) or source route transparent (SRT), to prevent unexpected blocking of one type of traffic.
Table 118 lists the SR Service parameters and commands.
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Syntax
FLush [!<port> | !*] -SR AllRoutes [Dec | Hex] [<Transparent | Null | route segment>] [Discover | Static]
SHow [!<port> | !*] -SR AllRoutes [Dec | Hex] [<Transparent | Null | route segment>] [Discover | Static] [<count>]
SHowDefault [!<port> | !*] -SR AllRoutes [Dec | Hex]
All routes in the routing table in decimal format
The AllRoutes parameter allows routes in the routing table to be flushed or displayed in decimal or hexadecimal format. The SHowDefault command displays static routes defined by the ADD -SR ROUte command. The SHow command displays static and discovered routes.
Dynamically learned routes used by LLC2 do not appear in the routing table. You cannot display, flush, or delete RIFs used by LLC2.
Values
Syntax
SETDefault -SR BridgeNumber = <number> (0-15) | 0x<number> (0-F)
SHow -SR BridgeNumber
3
The BridgeNumber parameter determines the bridge number to be used by the source route bridge.
For optimum performance, assign unique bridge numbers to 3Com token ring bridges on a given ring whenever possible. The token ring interface accepts all the frames that have the LAN-In ID (ring-in number) followed by the bridge number. Frames that do not have a known LAN-Out ID (ring-out number) following the LAN-In ID and bridge number are discarded. No functionality is lost when this advice is not followed. Changing the BridgeNumber causes all dynamically learned routes (end system source routes, or WAN routes learned on the Frame Relay, SMDS, or X.25 interface) to be flushed.
IBM bridges support hexadecimal-only format for bridge and ring numbers. 3Com token ring bridges support entry of both decimal and hexadecimal format for these parameters. Hexadecimal format entry must be preceded by a 0x.
To display the current value of BridgeNumber, enter the SHow command. The decimal format is displayed along with the hexadecimal format in parentheses.
Syntax
SHow [!<port> | !*] -SR CONFiguration
SHowDefault [!<port> | !*] -SR CONFiguration
No default
The CONFiguration parameter displays the current SR Service values for source route bridging, end system source route discovery, and source route transparent bridging gateway (SRTG). If a port number is specified, the display for port-related parameter values is limited to that port.
Syntax
SHow [!<port> | !*] -SR DIAGnostics
No default
The DIAGnostics parameter displays the current status of source route bridging and of the source route transparent bridging gateway. This parameter displays the common and potential configuration errors.
Syntax
SETDefault !<port> -SR GatewayControl = ([Enabled | Disabled], [IeeeMode | EtherMode], [AutoMode | NoAutoMode])
SHow [!<port> | !*] -SR GatewayControl
SHowDefault [!<port> | !*] -SR GatewayControl
Disabled, IeeeMode, AutoMode
The GatewayControl parameter controls the behavior of the SRTG. This parameter does not apply to SuperStack II NETBuilder bridge/router models 32x and 52x.
Values
If SRTG is configured with NoAutoMode, SRTG does not keep track of each transparent bridging station's encapsulation type. The final encapsulation format is decided by the setting of the IeeeMode or EtherMode settings. If EtherMode is selected, Ethernet II encapsulation with protocol type of 0x80D5 is used. Otherwise, LLC2-based packets are translated into the IEEE 802.3 format.
If AutoMode is selected, different packet translation rules are used for known and unknown stations. For known stations, the IeeeMode | EtherMode setting is ignored and the encapsulation format learned for those stations is used. For unknown stations, LLC-based packets are translated into both 802.3 and Ethernet Version II frames. Because non-LLC-based packets are not supported in this release, the DSAP field in the token ring 802.2 frame must be a multiple of 4's (that is, 00, 04, 08, so on), except for 0xBC and 0xE0, which are reserved for Banyan VINES and IPX, respectively.
Syntax
SETDefault -SR GatewayVRing = [None | <number>(1-4095) | 0x<number> (1-FFF)]
SHow -SR GatewayVRing
SHowDefault -SR GatewayVRing
None
The GatewayVRing parameter configures a virtual ring number for the transparent bridging domain and its ports, and views them as a single virtual ring. SRTG inserts the virtual ring number and its own bridge number as a pair to the RIF field before bridging transparent packets to the source route domain. The SRTG software can then determine on which ring to bridge packets from the source route domain on the return path.
The ring number can be entered in decimal or hexadecimal but must be preceded by a 0x when entered in hexadecimal. This parameter must be configured to activate the SRTG feature.
The GatewayVRing parameter does not apply to SuperStack II NETBuilder bridge/router models 32x and 52x.
Syntax
SETDefault !<port> -SR HoldTime = <minutes> (1-1440)
SHow [!<port> | !*] -SR HoldTime
SHowDefault [!<port> | !*] -SR HoldTime
15 minutes
The HoldTime parameter specifies the time interval in minutes that an inactive route entry can reside in the routing table.
SETDefault !<port> -SR LargestFrameSize = <number> (0-7)
SHow [!<port> | !*] -SR LargestFrameSize
SHowDefault [!<port> | !*] -SR LargestFrameSize
3 (4,399 octets)
The LargestFrameSize parameter specifies the maximum size frame that can be sent and received on a port. The source route bridge negotiates the largest frame size of all transit routes down to this size. This parameter should be used to regulate the amount of data transmitted by end systems to prevent timeouts due to slow network links. If the connected network contains low-speed WAN links, a lower largest frame size value should be assigned. Table 119 shows how the base values specified in IEEE 802.1D are supported.
| 1
These values are not supported.
|
Extended values listed in the IEEE specification are not currently supported.
Syntax
SETDefault !<port> -SR MaxAreRDLimit = <number> (0-8)
SHow [!<port> | !*] -SR MaxAreRDLimit
SHowDefault [!<port> | !*] -SR MaxAreRDLimit
8
The MaxAreRDLimit parameter specifies the maximum number of routing designators (RDs) (or hop count) allowed for an All Route Explorer (ARE) frame received on the specified port. The ARE is discarded after this limit is exceeded. The RD is a two-octet field in the routing information that designates a ring number (LAN ID) and bridge number.
The maximum All Route Explorer route designators (MaxAreRDLimit) allowed in a source route bridging environment is eight. This means that the maximum number of bridges or hops that can be daisy-chained in a source route bridge configuration is seven.
Syntax
SETDefault !<port> -SR MaxSteRDLimit = <number> (0-8)
SHow [!<port> | !*] -SR MaxSteRDLimit
SHowDefault [!<port> | !*] -SR MaxSteRDLimit
8
The MaxSteRDLimit parameter specifies the maximum number of RDs allowed for a spanning tree explorer (STE) frame received on the specified port. When MaxSteRDLimit is set to N (where N = 0-8), if an STE packet has crossed N-1 or fewer previous bridges, the packet is forwarded; otherwise, it is dropped.
Syntax
SETDefault !<port> -SR MinAccessPrior = <number> (0-6)
SHow [!<port> | !*] -SR MinAccessPrior
SHowDefault [!<port> | !*] -SR MinAccessPrior
4
The MinAccessPrior parameter determines the minimum access priority used for outgoing frames on a specified port. The lowest priority is 0; the highest is 6. End systems usually have a low access priority, while bridges have a medium. This allows bridges, which typically handle larger volumes of data, to get the token faster than end systems. If the user priority of the frame is greater than the minimum access priority, the user priority is used as the access priority. The user priority of the frame is determined by the access priority of an incoming token ring frame.
Syntax
SETDefault -SR Mode = [IEEE | PassiveBridging]
SHow -SR Mode
IEEE
The mode parameter defines the mode of source route bridging. The SHow command displays the current mode. If you select passive bridging, the same ring number must be assigned to all ports with the source route bridging enabled.
The Mode parameter does not apply to SuperStack II NETBuilder bridge/router models 32x and 52x.
Values
Syntax
SETDefault !<port> -SR RingNumber = [None | <number> (1-4095) | 0x<number> (1-FFF)]
SHow [!<port> | !*] -SR RingNumber
SHowDefault [!<port> | !*] -SR RingNumber
None
The RingNumber parameter determines the ring number or LAN ID for the specified port. This parameter must be defined before source route bridging is allowed on the port. A ring number must be assigned to a Frame Relay, SMDS, X.25, or Point-to-Point port in order to support source route bridging over these WAN interfaces. On a Frame Relay, SMDS, or X.25 port, the SR Service learns Frame Relay DLCIs, the SMDS individual address, or the X.25 DTE address associated with all remote bridges and their attached ring numbers. If you change the RingNumber value, the learned Frame Relay, SMDS, or X.25 routes are flushed.
IBM bridges support hexadecimal-only format for bridge and ring numbers. 3Com token ring bridges support entry of both decimal and hexadecimal format for these parameters. Hexadecimal format entry must be preceded by a 0x.
The SHow command displays the current value of the RingNumber parameter for a specific port or for all ports when the !* syntax is specified. The decimal format is displayed along with the hexadecimal format in parentheses.
Syntax
ADD !<port> -SR ROUte <media address> [Override] [Dec | Hex] [ Transparent | {Null | <source route> [<largestframesize>]}]
DELete !<port> -SR ROUte <media address>
SHow [!<port> | !*] -SR ROUte [[Cmac | Ncmac] %<media address>] [Dec | Hex]
SHowDefault [!<port> | !*] -SR ROUte [[Cmac | Ncmac] %<media address>] [Dec |Hex]
No default
The ROUte parameter configures, deletes, and displays a static route for a remote end system.
Values
Syntax
SETDefault !<port> -SR RouteDiscovery = ([All | None] | [AppleTalk | NoAppleTalk], [CLNP | NoCLNP], [DECnet | NoDECnet], [DLTest | NoDLTest], [IP | NoIP], [IPX | NoIPX], [LLC2 | NoLLC2], [VINES | NoVINES])
SHow [!<port> | !*] -SR RouteDiscovery
SHowDefault [!<port> | !*] -SR RouteDiscovery
None
The RouteDiscovery parameter specifies whether end system source routing is enabled on the port, and which routing protocols are being routed over the port.
Values
Syntax
SETDefault !<port> -SR SrcRouBridge = ([SrcRouBridge | NoSrcRouBridge])
SHow [!<port> | !*] -SR SrcRouBridge
SHowDefault [!<port> | !*] -SR SrcRouBridge
SrcRouBridge
The SrcRouBridge parameter enables source route bridging over a port.
Values
Syntax
FLush [!<port>| !*] -SR WanRoutes
SHow [!<port> | !*] -SR WanRoutes
No default (no WAN routes)
The WanRoutes parameter displays or flushes all learned remote routes. Each remote source route for a Frame Relay port has an associated Frame Relay address or data link connection identifier (DLCI). Each source route for an SMDS port has an associated SMDS individual address. Each source route for an X.25 port has an associated X25 DTE address.
FLush clears out all source routes learned across a Frame Relay, SMDS, or X.25 ring. This forces the end systems to redo the route discovery, since the SR bridge discards all traversing frames to and from the ring until the routes are relearned from the explorer frames. The learned routes are automatically flushed when the RingNumber or BridgeNumber is changed, or when source route bridging is turned off.
SHow displays all the currently learned source routes and the associated DLCI, SMDS individual address, or X.25 DTE address for each learned route. If the port is specified, the display for port-related parameter values is limited to that port.