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To make full use of Enterprise OS software, you need to understand the concept of ports and paths. This chapter provides basic concepts on ports and paths, including numbering, and describes how to configure basic ports and paths on the NETBuilder II® bridge/router, SuperStack® II NETBuilder® bridge/router, and OfficeConnect® NETBuilder bridge/router platforms.
This chapter covers basic port and path concepts only. Some platforms support virtual ports, and the NETBuilder II bridge/router supports port groups (logical networks). If you want to configure virtual ports or port groups, see the Configuring Advanced Ports and Paths chapter.
Ports and paths are the fundamental interface units on the bridge/router, and understanding the concept of ports and paths is important. This section defines ports and paths and explains how they are numbered on the following platforms:
The concepts in this section apply regardless of whether the bridge/router is used as a bridge or as a router.
The local and wide area interfaces available to you depend on your hardware platform and its configuration. For information on the types of interfaces your platform offers, see its installation guide.
The fundamental difference between paths and ports is that the path is the physical interface and the port is the logical interface in the software that is mapped to the physical path. Figure 1 illustrates the relationship between paths and ports.
Figure 1 Relationship Between Physical Paths and Logical Ports
A path is the physical interface that connects a bridge/router to a physical network medium such as an Ethernet bus, a token ring, or a serial line. In an Integrated Services Digital Network (ISDN) environment, a path also represents the channel over which data is transmitted. All NETBuilder bridge/routers provide several paths; each path is associated with a connector, such as an AUI, BNC, RS-232, or RS-449 connector, or a variety of others.
For software purposes, paths are numbered 1, 2, 3, and so on. The path number may be followed by a letter or a decimal and a channel number. For more information, see "Port and Path Numbering on NETBuilder II Multiport Modules" and to "Port and Path Numbering on a SuperStack II Bridge/Router" later in this chapter. For all SuperStack II bridge/router platforms, the connector configuration and the path number for each connector are fixed. For the NETBuilder II bridge/router, a connector takes its path number from the slot in which its module is installed. For more information on NETBuilder II path numbers, see "Port and Path Numbering on a NETBuilder II Bridge/Router"later in this chapter.
A port is the logical interface used by the software to represent a connection to a network. By default, there is a one-to-one correspondence between ports and paths, and they are usually numbered alike: for instance, port 1 is associated with path 1. All network traffic received on physical path 1 is treated by the software as arriving on logical port 1, and all traffic that the software transmits through logical port 1 passes through physical path 1. The same is true for the other ports and paths.
This default configuration is called a static port and path binding. A static path is a path that is mapped to a port. All paths are static by default.
You can redefine the default mapping using software commands. For example, you can redirect network traffic that is being routed through a particular logical port to a different physical path without manually switching cables on the connector.
Each logical port is usually associated with only one physical path. For token ring, Ethernet, Fiber Distributed Data Interface (FDDI), Frame Relay, Asynchronous Transfer Mode (ATM), X.25, and Switched Multimegabit Data Service (SMDS), the path-to-port ratio is always one to one. But for paths connected to serial lines, multiple paths can be associated with and statically bound to a single port if the Point-to-Point Protocol (PPP) is running over the port.
Paths can also be unbound from their ports and placed in a dial path pool to be shared by more than one port. The paths in the dial pool are called dynamic paths. A path in the dial pool can be dynamically bound to a port running PPP when the path is needed for data transfer events associated with dial-up. A dynamic path can also be bound to a port for dial backup purposes such as bandwidth-on-demand or disaster recovery. For more information about the use of the dial path pool, see the Configuring Port Bandwidth Management chapter.
The configuration of ports and paths on your NETBuilder II bridge/router depends on the combination of I/O modules installed. For information on acceptable I/O module configurations for 4-, 8-, and 8-slot extended chassis NETBuilder II bridge/routers, see the chassis guide that came with your NETBuilder II bridge/router.
Unlike other I/O modules used on the NETBuilder II bridge/router, the following modules have multiple physical connectors:
The port and path numbering for the HSS 8-port BRI module is slightly different than for other multiport modules. For more information, see "Port and Path Numbering for the HSS 8-Port BRI Modules"
Ports and paths on these four multiport modules are labeled differently from ports and paths on single-port modules. To differentiate one physical path or one logical port from another, you append a letter to the path or port number.
The Ethernet 2-Port 10BASE-FL module has two interfaces labeled A and B (see Figure 2). You add the upper- or lower-case letter A or B to the port number designation. For example, if the module is in slot 4, then the designation for interface B when entering software commands is !4B or !4b.
Figure 2 Ethernet 2-Port 10BASE-FL Module
The HSS V.35 3-Port module has three interfaces labeled A, B, and C (see Figure 3). The designations correspond to the markings on the V.35 adapter cable.
Figure 3 HSS V.35 3-Port Module
The Ethernet 6-Port 10BASE-T module has six connectors labeled A through F (see Figure 4).
Figure 4 Ethernet 6-Port 10BASE-T Module
To configure port or path settings on a multiport module, you must identify the slot number and the interface letter. For example, to configure settings for the Ethernet 2-Port 10BASE-FL module in slot 4 of the NETBuilder II hardware, use the path 4B. To assign a name to this path, enter:
SETDefault !4B -PATH NAme = "SJOSE"
To configure settings for interface A, you can use either 4 or 4A. For example, to name path 4A, enter one of the following commands:
SETDefault !4 -PATH NAme = "SFRAN"
SETDefault !4A -PATH NAme = "SFRAN"
For more information regarding multiport modules, see the module installation guides.
Because the HSS 8-Port BRI modules use built-in ISDN interfaces, the port and path numbering convention is different from other multiport modules.
The 8-Port BRI S/T and 8-Port BRI U modules have eight connectors labeled A through H (see Figure 5 ).
Figure 5 8-port BRI Module
The port and path numbers for the 8-port BRI modules have three components: the slot number, the interface letter (specified with the appropriate letter A through H), and the channel number. For example, the path number for interface A on slot 1 with channel 1 would be 1A.1. To enable the path, enter:
SETDefault !1A.1 -PATH CONTrol = Enable
Or, the path number for interface H on slot 6 with channel 2 would be 6H.2. To enable this path, enter:
SETDefault !6H.2 -PATH CONTrol = Enable
The special HSS 8-port BRI module command syntax applies to both the S/T and U BRI modules. The same conventions also apply to port numbers.
By default, 8-port BRI module ports are included in the dial pool when the bridge/router is reset. If you do not want the ports to be in the dial pool, you must change them to the static path and bind the port to the paths using:
SETDefault !<connectorID.channelID> -PATH DialCONTrol = STAtic
ADD !<port> -PORT PATHs <connector.ID.channelID [,...]> | SCID"<SyscallerID>"
SETDefault !<path> -PATH CONTrol = Enable
SETDefault !<port> -PORT CONTrol = Enable
For example, to remove port 4A.2 from the dial pool and bind it to a static path, enter:
SETDefault !4A.2 -PATH DialCONTrol = STAtic
ADD !4A.2 -PORT PATHs !4A.2
SETDefault !4A.2 -PATH CONTrol = Enable
SETDefault !4A.2 -PORT CONTrol = Enable
For more information about ISDN port and path numbering, see "Port and Path Numbering Issues for Built-in ISDN Interfaces" later in this chapter. For more information about the HSS 8-port BRI modules, see Installing the NETBuilder II HSS 8-Port BRI Module.
Table 1, Table 2, Table 3 and Table 4 outline the default port and path numbering for model 2xx, 42x, 32x, and 52x SuperStack II NETBuilder bridge/routers.
| 1
The connector associated with paths 2.1, 2.2 cannot be reconfigured.
|
| 1
This connector can be converted to an X.21, V.35, V.36, RS-449, or RS-232 connector using cables. For more information, see your SuperStack II installation guide.
|
| 1
The connector and port associated with paths 2.1, 2.2, 3, and 4 cannot be reconfigured.
|
The port and path numbering conventions for built-in ISDN interfaces differ from other port and path types. For more information, see "Port and Path Numbering Issues for Built-in ISDN Interfaces" later in this chapter.
Before configuring ports and paths for the ISDN interface on your SuperStack II bridge/router, you must decide how you want to use the ISDN interface. For more information, see the Configuring Wide Area Networking Using ISDN chapter.
Table 5, Table 6, and Table 7 outline the default port and path numbering for model 11x, 12x, and 14x OfficeConnect NETBuilder bridge/routers.
The port and path numbering conventions for built-in ISDN interfaces differ from other port and path types. For more information, see "Port and Path Numbering Issues for Built-in ISDN Interfaces" later in this chapter.
Before configuring ports and paths for the ISDN interface on your OfficeConnect NETBuilder bridge/router, you must decide how you want to use the ISDN interface. For more information, see the Configuring Wide Area Networking Using ISDN chapter.
You can reconfigure the software so that multiple paths are mapped to one wide area port by entering the ADD -PORT PAths command. If you assign multiple paths to a wide area port, the port must be running PPP. You can configure multiple paths to a wide area port for the following situations:
Figure 6 shows two sample topologies: the left topology has one path mapped to one port and the right topology has two paths mapped to one port (for disaster recovery or bandwidth-on-demand). In the left topology, path 2 is assigned by default to port 2. In the right topology, the software has been reconfigured so that paths 3 and 4 are mapped to port 3.
Figure 6 Possible Path-to-Port Assignments on a SuperStack II Bridge/Router
You can also assign one path to one wide area port and one path to another wide area port. In Figure 7, path 2 is assigned to port 2 and path 3 is assigned to port 3. Configure your wide area ports and paths as shown in this figure only if you plan to implement the Boundary Routing network resiliency feature on your SuperStack II NETBuilder bridge/router.
Figure 7 Setting Up Two Wide Area Ports on a SuperStack II Bridge/Router
Built-in ISDN ports use a different path numbering convention from other paths. Each B channel is assigned a different path. For instance, 3.1 and 3.2 are path numbers for a built-in ISDN port, where 3 is the connector ID, and 1 and 2 are the channel IDs. Some commands require you to specify the connector ID and channel ID of an ISDN path.
If you do not specify a channel number for a parameter that requires it, the parameter is configured for channel 1 only. If you want to specify all channels associated with a physical interface, specify the connector number and an asterisk (for example, 2.*).
If you are unsure how to specify a path, see the description of the parameter in Reference for Enterprise OS Software.
When using an ISDN TA connected to a serial port, both B channels are assigned the same path number. You do not need to use the special ISDN syntax.
The syntax variation for these parameters is presented in Reference for Enterprise OS Software in the following format:
SETDefault !<path> -PATH remoteDialNo = "<string>"
SHow [!<path> | !*] -PATH remoteDialNo
SHowDefault [!<path> | !*] -PATH remoteDialNo
SETDefault !<connectorID.channelID> -PATH remoteDialNo = "<string>"
SHow [!<connectorID.channelID> | !<connectorID>.*] -PATH remoteDialNo
SHowDefault [!<connectorID.channelID> | !<connectorID>.*] -PATH remoteDialNo
Enterprise OS software menus and help strings do not display the syntax variation for ISDN interfaces.
For more information about configuring ISDN, see the Configuring Wide Area Networking Using ISDN chapter.
To set up ports and paths for local area interfaces on a bridge/router, follow these steps:
1 . Assign a name to path 1 (optional) using:
SETDefault !<path> -PATH NAme = "string"
SETDefault !1 -PATH NAme = "FLOOR_1"
2 . If you have a model 32x or 52x SuperStack II bridge/router, follow these steps:
SETDefault !<port> -PATH BAud = 4000 | 16000
SETDefault !<path> -PATH CONTrol = ([Enabled | Disabled])
For example, to enable path 1, enter:
SETDefault !1 -PATH CONTrol = Enabled
3 . Assign a name to port 1 (optional) using:
SETDefault !<port> -PORT NAme = "string"
SETDefault !1 -PORT NAme = "BLDG_1"
4 . Disable all local area ports that you are not using by entering for each port:
SETDefault !<port> -PORT CONTrol = Disabled
3Com recommends that you disable all ports you do not use. Disabling unused ports improves bridge/router performance.
5 . Repeat steps 1 through 4 for each local area port and local area path on your bridge/router.
This completes the setup procedure for local area ports and paths. To set up wide area ports and paths, go to the next section. To configure bridging or routing protocols, see the bridging and routing chapters in this guide.
This section describes how to set up ports and paths for wide area interfaces on a bridge/router. To set up ports and paths for local area interfaces, follow the procedure described in "Configuring Local Area Interfaces" earlier in this chapter.
Before configuring ports and paths for the ISDN interface on SuperStack II bridge/routers with ISDN interfaces, you must decide how you want to use the ISDN interface. For more information about ISDN, see the Configuring Wide Area Networking Using ISDN chapter.
To set up ports and paths on a bridge/router with wide area interfaces, follow these steps:
1 . Assign a name to the path (optional) using:
SETDefault !<path> -PATH NAme = "string"
SETDefault !3 -PATH NAme = "SF-SJ"
2 . If necessary, reconfigure the connector type for the path using the SETDefault -PATH CONNector command (the syntax varies depending on the platform you are using).
Table 8 summarizes which connector type to select if you have converted the serial connector labelled B on model 32x and 52x SuperStack II bridge/routers.
On a SuperStack II bridge/router with an RS-449 cable installed, the software cannot distinguish between the RS-449 cable and an V.35 cable. You must configure the -PATH CONNector parameter to RS-449; otherwise, the software assumes the cable is a V.35.
3 . If necessary, reconfigure the transmit clock setting for the serial path using:
SETDefault !<path> -PATH CLock = TestMode | External | Internal
If you connect two NETBuilder II or SuperStack II bridge/routers to a NETBuilder II bridge/router with an HSS V.35 3-Port WAN interface, you must use a modem eliminator and set the CLock parameter to External on both devices. Contact your 3Com supplier for a suggested list of modem eliminators.
4 . If necessary, reset the baud rate for the path using:
SETDefault !<path> -PATH BAud = <kbps>
SETDefault !3 -PATH BAud = 256
It is important to set the baud rate even if you use an external clock. The bridge/router uses the baud rate setting to allocate resources for a path, compute metrics, and select a forwarding path.
5 . If the port is running PPP and you plan to use the features that use multiple paths mapped to a port (see "Configuring Multiple Paths to a Wide Area Port" earlier in this chapter), assign a path or multiple paths to each port using the ADD !<port> -PORT PAths command (the syntax varies depending on the platform you are using).
ADD !3 -PORT PAths 3,4
ADD !2 -PORT PAths SCID "Boston"
6 . If you have previously disabled the path, changed the value of the BAud, CLock, or CONNector parameters, or assigned multiple paths to one port, re-enable the path using:
SETDefault !<path> -PATH CONTrol = Enabled.
7 . Repeat steps 1 through 6 for each wide area path you configure.
8 . If necessary, enable or disable the wide area port.
SETDefault !<port> -PORT CONTrol = Enabled | Disabled
9 . Assign a name to the port (optional) using:
SETDefault !<port> NAme = "string"
SETDefault !3 -PORT NAme = "SanJose"
10 . If necessary, change the default owner of the wide area port using:
SETDefault !<port> -PORT OWNer = ETHernet | TokenRing | FDDI | PPP | FrameRelay | BSC | ATUN | SHDLC | SMDS | X25 | WanExtender | SDLC | ATM | LoopBack | Auto
11 . Repeat steps 8 through 10 for each wide area port you configure.
12 . Disable each port that you are not using by entering:
SETDefault !<port> -PORT CONTrol = Disabled
3Com recommends that you disable all ports you do not use. Disabling unused ports improves bridge/router performance.
Many configurations and WAN technologies require the use of virtual ports. If you need to configure virtual ports, see the Configuring Advanced Ports and Paths chapter. To configure bridging or routing protocols, see the bridging and routing chapters in this guide. Table 10 lists the primary bridging and routing protocols in this guide.