[Top] [Prev] [Next] [Bottom]
This chapter discusses how to create locations-settings for dial-out destinations-for dial-out connections.
This chapter discusses the following topics:
A location defines a dial-out destination and the characteristics of the dial-out connection. Locations control dial-out network connections in much the same way the user table controls dial-in network connections.
Locations are stored in the location table. All dial-out locations have the following minimum settings:
You must create a unique dial-out location for each remote host or router you want to access. Location table entries are identified by this unique location name, which can contain up to 12 characters.
To create a location, use the following command:
Because the default method of initiating a connection is manual, you need to use the dial command to cause the PortMaster to manually dial out to a location. You can change the connection type as shown in Table 8-1. If you are changing an existing location's connection type, verify that the connection is not active.
To configure the connection type, use the following command:
Dial-on-demand connections to selected locations can save money because the telephone line is used only when traffic needs to be transmitted. The dial-on-demand configuration can also be used as a backup for other types of connections such as those using high-speed synchronous lines. A dial-on-demand connection usually has the idle timer set so that the connection is closed when no longer needed.
Note ¯ 
When configuring a dial-on-demand location, be careful not to have the on-demand location be the route to the loghost, RADIUS server, RADIUS accounting server, or any host for a port using the PortMaster login or device service, unless you understand the effect of these services upon dial-on-demand.
If routing for a dial-on-demand location is set to on, listen, or broadcast, the PortMaster dials out to that location when it boots, to update routing information. The PortMaster hangs up when the idle timer expires because RIP traffic does not reset the idle timer.
To configure a location to support a dial-on-demand connection, use the following command:
To establish a continuous dial-out connection, you must set the location type to continuous. In this configuration, the PortMaster dials out after it boots and establishes a network connection to the specified location. If the connection is dropped for any reason, the PortMaster dials out again and establishes the connection again after a 30-second wait.
To configure a location to support a continuous connection, use the following command:
Use manual dial-out to test the connection or if you want the connection to be established only when you or a network callback user requests. You should test any connection before configuring it as a continuous or on-demand location.
To configure a location to support a manual connection, use the following command:
Note ¯ 
Disconnect dial-out connections by resetting the port before switching a connection type from manual to on demand,.
The telephone number setting is used to dial out to the remote location.
To set the telephone number of the remote location, use the following command:
The username and password are what the PortMaster uses to authenticate itself to the remote host. Note that the username and password you enter here must also be resident on the remote host (in the user table, RADIUS, or other authentication mechanism).
To set the username and password, use the following commands:
The network protocol for a dial-out location can be set for PPP packet encapsulation, SLIP encapsulation, or a Frame Relay subinterface. PPP can be used with either or both IP and IPX packet routing. You should select a protocol that is compatible with the remote location.
Note ¯ 
New location table entries default to PPP.
To set the protocol for a location, use the following command:
For more information about setting the location protocol to a Frame Relay subinterface, see "Frame Relay Subinterfaces" on page 13-13.
The destination IP address is the IP address expected on the system at the remote end of the dial-out connection.
For PPP connections, you can either specify an IP address or have it negotiated. If you enter 255.255.255.255 (negotiated) for the destination IP address, the PortMaster learns the IP address of the remote system during PPP IPCP negotiation.
For SLIP connections and locations set for on-demand dialing, enter the IP address or a valid hostname of the system at the remote end of the connection.
Note ¯ 
Assigned addresses are not supported for dial-out locations.
To set the destination IP address for a location, use the following command:
If the host or network on the remote end of the connection requires a netmask, you must define it in the location table.
To set the destination netmask for a location, use the following command:
If you are using the IPX protocol, you must assign a unique IPX network number to the network connection between the remote host and the PortMaster. Enter the IPX network number in the hexadecimal format described in Appendix A, "Networking Concepts." The number can consist of up to eight characters. The number is used only for the serial link, and must be different from the IPX network numbers used for Ethernets at either end.
To set the IPX network number for a location, use the following command:
Note ¯ 
Do not set a value of all 0s (zeros) or all Fs for the IPX network numbers.
You can associate RIP routing with locations-for example, a dial on-demand connection where the remote router is defined as a location on the local PortMaster.
As described in the PortMaster Routing Guide, PortMaster products automatically send and accept route information as RIP messages.
See the PortMaster Routing Guide for instructions on configuring OSPF routing or configuring BGP routing.
To set RIP routing for a location, use the following command:
Table 8-2 describes the results of using each keyword.
Note ¯ ComOS releases prior to 3.5 use routing instead of the rip keyword.
Dial groups associate locations with specific dial-out ports. By default, all ports and locations belong to dial group 0 (zero). You can configure locations and ports into dial groups numbered from 0 to 99. Dial group numbers can be used to reserve ports for dial-out to specific locations, or to differentiate among different types of modems that are compatible with the remote location.
The dial group associated with a location works with the dial group specified for each port. For example, you create a dial-out location called home and specify that the dial group for home is 2. When you configure each port, you can assign the port to a dial group. Only ports assigned to group 2 will be used to dial the location home, while other ports will not.
To associate a location with a dial group number, use the following command:
The maximum transmission unit (MTU) defines the largest frame or packet that can be sent through this port, without fragmentation. If an IP packet exceeds the specified MTU, it is automatically fragmented. An IPX packet that exceeds the specified MTU is automatically dropped. PPP connections can have a maximum MTU of 1500 bytes. SLIP connections can have a maximum MTU of 1006 bytes. With PPP, the PortMaster can negotiate smaller MTUs when requested during PPP negotiation.
The MTU is typically set to the maximum allowed for the protocol being used. However, smaller MTU values can improve performance for interactive sessions. During PPP negotiation, the smaller number is used. If you are using IPX, the MTU should be set to at least 600.
To set the MTU for a location, use the following command:
Compression of TCP/IP headers can increase the performance of interactive TCP sessions over network hardwired asynchronous lines. PortMaster products use Van Jacobson TCP/IP header compression and Stac LZS data compression. Compression is on by default.
Compression cannot be used with multiline load-balancing, but can be used with Multilink PPP.
Compression must be enabled on both ends of the connection if you are using SLIP. With SLIP, TCP packets are not passed if only one side of the connection has compression enabled. For PPP connections, the PortMaster supports both bidirectional and unidirectional compression. Refer to RFC 1144 for more information about header compression.
The PortMaster supports Stac LZS data compression only for PPP connections with bidirectional compression. Stac LZS data compression cannot be used for SLIP connections.
To configure compression for a location, use the following command:
Table 8-3 describes the results of using each keyword.
You can set the idle timer for a location with manual or on-demand connections. This timer defines the length of time the line can be idle, with no network traffic in either direction, before the PortMaster disconnects the connection. You can set the idle time in seconds or minutes, to any value from 0 to 240. The default setting is 0 minutes. If the value is set to 2 seconds or a longer interval, the port is reset after having no traffic for the designated time. The idle timer is not reset by RIP, keepalive, or SAP packets. To disable the idle timer, set the value to 0.
Note ¯ 
Idle timers for dial-in connections are set on each port or for specific users. Idle timers for dial-out connections are set in the location table.
To set the idle time for a location with a manual or on-demand connection, use the following command:
The PortMaster supports data-over-voice for inbound and outbound ISDN connections. The PortMaster automatically accepts inbound voice calls and treats them as data calls. You can force a data-over-voice call on an outbound ISDN connection by setting the capability to on.
To turn on the data-over-voice capability for ISDN connections to a location, use the following command:
For more information on ISDN connections, see Chapter 11, "Configuring the PortMaster 3," and Chapter 12, "Using ISDN BRI."
When you enter a username and password into the location table, they are used as the system identifier and MD5 secret for CHAP authentication. You can turn on outbound CHAP authentication and eliminate the need to use the sysname identifier and user table configurations for CHAP, unless the device being dialed also dials in to the PortMaster. The default setting is off.
To set CHAP authentication for a location, use the following command:
The PPP protocol supports the replacement of nonprinting ASCII data in the PPP stream. These characters are not sent through the line, but instead are replaced by a special set of characters that the remote site interprets as the original characters. The PPP asynchronous map is a bit map of characters that should be replaced. The lowest-order bit corresponds to the first ASCII character NUL, and so on. Most environments should set the asynchronous map to 0 (zero) to achieve maximum throughput.
To set the PPP asynchronous map for a location, use the following command:
You can set several ports to connect to a single location to distribute heavy traffic loads. This capability is called multiline load balancing. You can define a threshold known as a high-water mark for a location. The high-water mark triggers the PortMaster to bring up an additional connection to the location when the amount of data specified by the high-water mark is queued. The PortMaster examines the queue several times a minute to determine if the high-water mark has been reached.
Load balancing is useful for on-demand routing because additional ports for the location are added as the load exceeds what can be handled by one port. When the ports are idle for the time specified by the set location idletime command (see "Setting the Idle Timer" on page 8-10), all ports used for that connection are timed out simultaneously.
Load balancing can save you money because you do not need to configure your network to handle the maximum load between locations. Periods of heavy traffic can be handled by additional ports on an as-needed basis. At other times, the additional ports can be used for other purposes.
When multiple ports are in use, each packet is queued on the port with the least amount of traffic in the queue. Ports with very different speeds should not be combined for load balancing purposes. The overall throughput for a given number of ports is approximately equal to the number of ports multiplied by the throughput of the slowest port.
The following settings are used to configure load balancing and define when additional lines to this location are dialed.
To configure load balancing, you must define the number of dial-out ports that can be used to dial and establish a connection with this location. This setting creates a pool of ports that can be used at the same time to establish a connection with this location.
If the maximum number of ports is set to 0, no connection with this location is established. If the maximum number of ports is set to any number greater than one, the high-water mark is used to determine when additional connections are established with this location.
When more than one line is open to a given location, the PortMaster balances the load across each line. When the ports are idle for the time specified by the set location idletime command (see "Setting the Idle Timer" on page 8-10), all ports used for that connection are timed out simultaneously.
To set the maximum number of dial-out ports for a location, use the following command:
Bandwidth-on-demand determines when an additional line to this location should be established. The PortMaster uses the high-water mark setting to configure bandwidth-on-demand
The high-water mark specifies the number of bytes of network traffic that must be queued before the PortMaster opens an additional connection. The PortMaster examines the queue several times a minute to determine if the high-water mark has been reached.
If you set a very small threshold number, the PortMaster quickly opens the maximum number of ports you specified for this location. When you are deciding on a threshold, keep in mind that interactive traffic from login users queues a relatively small number of bytes, only several hundred. However, network users doing file transfers can queue several thousand bytes of traffic. These activities should be considered before you set your dial-out threshold.
This value is used only when the maximum number of ports is greater than one. The default high-water mark is zero.
To set the high-water mark in bytes for a location, use the following command:
You can attach input and output filters to each location. Filters must be defined in the filter table before they can be added to the location table. For more information about filters, see Chapter 9, "Configuring Filters." When a filter is changed, all ports in use by the location must be reset to have the changes take effect.
Note ¯ 
If a matching filter name is not found in the filter table, this command is not effective and all traffic is permitted.
Input filters cause all packets received from the interface to be evaluated against the filter rule set. Only packets allowed by the filter are accepted.
To set an input filter for a location, use the following command:
Output filters cause all packets going out to the interface to be evaluated against the filter rule set. Only packets allowed by the filter are passed out to the interface.
To set an output filter for a location, use the following command:
When you are configuring a location, you can set a manual connection for the location so that you can test the configuration before resetting the connection to on-demand or continuous. To test the configuration, you must initiate a connection with the remote location by using the dial command from the command line.
To display the chat script (if you are using one) during dialing, use the optional -x keyword. You can watch the connection process to ensure that location-specific settings are configured correctly. This keyword also resets some debugging values previously set with set debug.
When your location is configured correctly, change the connection type from manual to continuous or on-demand.
To test your configuration, use the following command:
[Top] [Prev] [Next] [Bottom]
spider@livingston.com
Copyright © 1998, Livingston Enterprises, Inc. All rights
reserved.
The location table is not used for dialing out with the tip command or UUCP. For information on these applications, refer to Chapter 18, "Accessing Shared Devices."