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Table Of Contents
Establish the Route to the Remote Network
Enable AAA and Static Route Download
Enable Access to the AAA Server
Enable SGBP Dialout Connection Bidding
Monitor and Maintain the Large Scale Dialout Network
Stack Group and Static Route Download Configuration Example
Primary Network Access Server Configuration Example for NAS1
Secondary Network Access Server Configuration Example for NAS2
Router Remote Configuration Example
Sample User Profile on an Ascend RADIUS Server for NAS1
Asynchronous Dialing Configuration Examples
Asynchronous Dialing Configuration Example
Asynchronous and Synchronous Dialing Configuration Example
aaa authorization configuration default
Large Scale Dialout
Feature Summary
In previous dial-on-demand routing (DDR) networking strategies, only incoming calls could take advantage of features such as dialer and virtual profiles, Multichassis Multilink PPP (MMP) support, and the ability to use an authentication, authorization, and accounting (AAA) server to store attributes. MMP allows network access servers to be stacked together and appear as a single network access server chassis so that if one network access server fails, another network access server in the stack can accept calls. MMP also provides stacked network access servers access to a local Internet point of presence (POP) using a single telephone number. This allows for easy expansion and scalability, as well as assured fault tolerance and redundancy. Now with large scale dialout, these features are available for both outgoing and incoming calls.
Large scale dialout eliminates the need to configure dialer maps on every network access server for every destination. Instead, you create remote site profiles containing outgoing call attributes (telephone number, service type, and so on) on the AAA server. The profile is downloaded by the network access server when packet traffic requires a call to be placed to a remote site.
Additionally, large scale dialout addresses congestion management by seeking an uncongested, alternative network access server within the same POP when the designated primary network access server experiences port congestion.
As an added benefit, large scale dialout enables scalable dial-out service to many remote sites across one or more Cisco network access servers or Cisco routers. This is especially beneficial to both Internet service providers and large scale enterprise customers because it can simplify network configuration and management. Large scale dialout streamlines activities such as service maintenance and scheduled activities like application upgrades from a centralized location. Large enterprise networks such as those used by retail stores, supermarket chains, and franchise restaurants can use large scale dialout to easily update daily prices and inventory information from a central server to all branch locations in one process, using the same network access servers they currently use for dial in functions.
Benefits
Benefits of using large scale dialout include the following:
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Allows dialing the same router from any router in a stack group. Using a primary network access server, you can configure static routes for a given remote host or network. If the primary network access server is congested or has no links available, it will search for an alternate server within the stack, and force that server to dial out.
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List of Terms
Authentication, authorization, and accounting server (AAA)—Typically a CiscoSecure ACS, TACACS+, or RADIUS server.
Domain Name System (DNS)—System used in the Internet for translating names of network nodes into addresses.
Dynamic static route (DSR)—A static route that has been installed by means other than configuration, such as AAA server authorization.
Multichassis Multilink PPP (MMP)—Extends Multilink PPP support across multiple routers and access servers. MMP enables multiple routers and access servers to operate as a single, large dial-up pool, with a single network address and ISDN access number. MMP correctly handles packet fragmenting and reassembly when a user connection is split between two physical access devices.
Network access server—This device typically has PSTN interfaces and answers or dials PSTN calls.
Oversubscription—Number of users serviced by a network access server is larger than the number of ports available.
Point of presence (POP)—A physical location where interexchange carrier installed equipment interconnects with a local exchange carrier.
Port congestion—Occurs when the network access server resources have been consumed to predetermined level. In the extreme case, an network access server with all ports connected is experiencing a Port Congested error condition.
Primary network access server—Each remote site has a designated primary network access server. The primary network access server is the first choice for dialout operations.
Public Switched Telephone Network (PSTN)—Traditional telephone or ISDN network.
Secondary network access server—An alternative choice for dialout when port congestion occurs.
Stack Group Bidding Protocol (SGBP)—A critical component used in multichassis, multilink sessions. The SGBP unites each Cisco access server in a virtual stack, which enables the access servers to become virtually tied together. Each independent stack member communicates with the other members and determines which device CPU should be in charge of running the multilink session and packet reassembly. The goal of SGBP is to find a common place to forward the links and ensure that this destination has enough system processor space to perform the segmentation and packet reassembly.
Restrictions
Consider these restrictions when configuring large scale dialout:
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Platforms
This feature is supported on these platforms:
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Prerequisites
The following prerequisites apply to large scale dialout:
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Additionally, all members of the stack group must be in the same routing autonomous system, and the redistribute static and redistribute connected commands must already be configured. The stack group supports all routing protocols, but routing protocols such as EIGRP and OSPF, which support redistributing static and connected routes and Flash memory updates when topology changes, are recommended.
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You will also need to configure your network access server to communicate with the applicable security server, either a TACACS+ or RADIUS daemon.
If you are using RADIUS and Ascend attributes, use the non-standard keyword with the radius-server host command to enable your Cisco router, acting as a network access server, to recognize that the RADIUS security server is using a vendor-proprietary version of RADIUS. Use the radius-server key command to specify the shared secret text string used between your Cisco router and the RADIUS server. For more information, refer to the "Configuring RADIUS" chapter in the Cisco IOS Release 12.0 Security Configuration Guide.
If you are using TACACS+, use the tacacs-server host command to specify the IP address of one or more TACACS+ daemons. Use the tacacs-server key command to specify the shared secret text string used between your Cisco router and the TACACS+ daemon. For more information, refer to the "Configuring TACACS+" chapter in the Cisco IOS Release 12.0 Security Configuration Guide.
Supported MIBs and RFCs
No MIBs or RFCs are supported by this feature.
Functional Description
Large scale dialout enables scalable dialout service, that is, configuration information is stored in a central server and many network access servers can access this information using either the RADIUS or TACACS+ protocols. One or more network access servers can advertise summary routes to the remote destinations, then dynamically download the dialout profile configurations as needed.
Large scale dialout also allows dialing the same remote network or host from any router in a stack group.You configure static routes for a particular remote host or network on a router in a stack group that you designate as the primary network access server for that remote. When a primary network access server experiences port congestion, it searches for an alternate network access server within the stack group to dial out, and when found, forces the alternate to dial the remote network. illustrates the large scale dialout solution.
Figure 1 Large Scale Dailout Components
Large scale dialout relies on per-user static routes in AAA, and redistributed static and redistributed connected routes to put better routes pointing to the same remote on the alternative network access server. You can use any routing protocol that supports redistributing static and connected routes, and supports flash updates when a routing topology changes. The OSPF and EIGRP routing protocols are recommended.
Next Hop Definition
A next hop address or remote name that you define is used in a AAA server lookup to retrieve the remote network's or host's user profile. The name is passed to the AAA server by the router software.
Static Routes
Static routes can be dynamically downloaded from an AAA server by the network access servers, or be manually configured on the network access servers.
Dynamic static routes are installed on the network access server by an AAA server. The routes are downloaded at system startup and updated periodically, so that route changes are reflected within a configurable interval of time. Large scale dialout allows multiple AAA transactions with 50 static routes per AAA server transaction. There is no set limit for the number of AAA server transactions which can be configured, however configuring too many transactions may impact the performance of your network. Performance effects will depend on the configurations and platforms used in your network.
Stack Groups
The network access server stack group redistributes the routes of the remote networks. If the number is large, the routes are summarized. Packets destined for remote networks are routed to the primary network access server for the remote network.
If the static route pointing to the next hop of the network access server has a name, that name with the -out suffix attached becomes the profile name. If no profile name is configured in the route statement defining the remote location, the router can use reverse DNS lookup to map the IP route to a profile name. The next hop address on the static route is used in reverse DNS to obtain the name of the remote network. This name is then used in the AAA server lookup to retrieve the remote's user profile. If no name is returned by DNS, the network access server uses the destination IP address with the -out suffix appended as the name.
If the primary network access server is congested, an alternate network access server may dial out. The primary network access server initiates stack group bidding for the outoing call. The least congested network access server wins the bid and downloads the user profile. After a call is connected on an alternate network access server, a better per-user route from the AAA profile is installed on the alternate network access server. Subsequent packets destined for the remote network are routed to the alternate network access server while the call is connected. Packets stored in the dialer hold queue on the primary network access server are switched to the alternate network access server when the new route is distributed to the primary network access server.
Configuration Tasks
The tasks to configure large scale dialout are described in the following sections:
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See the examples in the section "Configuration Examples" for ideas on how you can implement large scale dialout in your network.
Establish the Route to the Remote Network
This task is optional; you only need to perform it when routes will not be downloaded statically from the AAA server.
To establish a route to the remote network or host (next hop) holding the user profile, use the ip route command in global configuration mode:
ip route network-number [network-mask]
{address | interface} [distance]
[name name]Establish a static route to a remote network to obtain a user profile.
The name you define is used in an AAA server lookup to retrieve the remote network's AAA profile.
Enable AAA and Static Route Download
AAA network security must be enabled before performing the tasks in this section. For more information about enabling AAA, refer to the "AAA Overview" chapter in the Cisco IOS Release12.0 Security Configuration Guide.
Enabling the static route download feature allows static routes to be configured at a centrally located AAA server. Static routes are downloaded when the system is started, and you define a period of time between route updates when you enable the feature.
Note
To enable the static route download feature, use the following commands in global configuration mode:
Use the show ip route command to see the routes installed by these commands.
Enable Access to the AAA Server
To configure the dialer interface to be able to access the AAA server and retrieve the user profile, use the following command in interface configuration mode for a dialer rotary group leader:
dialer aaa
Allow the dialer to use the AAA server to locate profiles for dialing information.
Enable Reverse DNS
To instruct the dialer to use reverse DNS on dial out, use the following command in interface configuration mode:
The user profile name passed to the AAA server by the system is reverse-dns-name-out; the -out suffix is automatically appended to the DNS name, and is required to create unique dialout and dial in profiles.
Enable SGBP Dialout Connection Bidding
You must configure SGBP before performing the tasks in this section. The Dial Solutions Configuration Guide describes the tasks you perform to configure a stack group.
To configure stack group bidding, use the following command in global configuration mode:
Once the stack group has been configured and enabled for dialout connection bidding, configure the dialer interface to search for an alternate network access server in the event of port congestion. Use the following commands in interface configuration mode:
Additional dialer interface configuration information and commands are found in the Dial Solutions Configuration Guide and the Dial Solutions Command Reference books.
Define a User Profile
Attributes are used to define specific AAA elements in a user profile. Large scale dialout supports a subset of Ascend attribute-value (AV) pairs, RADIUS attributes, and a map class attribute providing outbound dialing services, as described in .
The only required attribute is the Cisco AV pair outbound:dial-number; all others are optional. If the AAA server does not support Cisco AV pairs, attribute #227, Ascend-Dial-Number, can be substituted. In cases where there are equivalent Cisco AV pairs and Ascend-specific attributes, Cisco recommends using the Cisco AV pairs.
For additional information about defining user profiles, see the chapter "RADIUS Attribute-Pairs" in the CiscoSecure ACS for Windows NT User Guide 2.0, and the chapter "TACACS+ Attribute-Value Pairs" in the Cisco IOS 12.0 Security Configuration Guide.
For an example of a user profile using the supported attributes, see the section "Sample User Profile on an Ascend RADIUS Server for NAS1" later in this document.
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Monitor and Maintain the Large Scale Dialout Network
Use any of the following EXEC commands to monitor and maintain a large scale dialout network:
Configuration Examples
This section provides the following examples of how you can configure large scale dialout in your network:
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Stack Group and Static Route Download Configuration Example
In the following example, NAS1 will be configured as the primary network access server and NAS2 as the secondary network access server, in a stack group for dialout. The remote router is configured to answer calls. illustrates the configuration.
Figure 2 Stack Group and Static Route Download Configuration
At the console for NAS1, ping 20.1.1.1. This creates a multilink bundle with two links. NAS1 dials out the first link, and NAS2 dials out the second link. The router Remote is using the CHAP hostname echo-8.cisco.com.
A user profile for NAS1 on an Ascend RADIUS server is listed in the section "Sample User Profile on an Ascend RADIUS Server for NAS1."
Primary Network Access Server Configuration Example for NAS1
version 12.0service timestamps debug datetime msecservice timestamps log datetime msecservice password-encryption!hostname NAS1!aaa new-modelaaa authentication ppp default radius localaaa authorization network default radius noneaaa authorization configuration default radiusaaa route download 720enable password 7 1236173C1B0F!username NAS2 password 7 05080F1C2243username NAS1 password 7 030752180500username dialbid password 7 121A0C041104username echo-8.cisco.com password 7 02050D480809ip subnet-zeroip domain-name cisco.comip name-server 172.31.2.132ip name-server 172.22.30.32!virtual-profile virtual-template 2!sgbp group dialbidsgbp seed-bid offloadsgbp member NAS2 172.21.17.17sgbp dial-bidsisdn switch-type basic-5ess!!interface Ethernet0ip address 172.21.17.18 255.255.255.0no ip directed-broadcastno ip mroute-cachemedia-type 10BaseTno cdp enable!interface Virtual-Template1ip address 1.1.1.1 255.255.255.252no ip directed-broadcast!interface Virtual-Template2ip unnumbered Virtual-Template1no ip directed-broadcastppp multilinkmultilink load-threshold 1 outbound!interface BRI0description PBX 60043no ip addressno ip directed-broadcastencapsulation pppdialer rotary-group 1isdn switch-type basic-5essno fair-queue!interface Dialer1ip unnumbered Ethernet0no ip directed-broadcastencapsulation pppno ip mroute-cachedialer in-banddialer dnsdialer aaadialer hold-queue 5dialer congestion-threshold 5dialer reserved-links 1 0dialer-group 1no fair-queueppp authentication chap callinppp multilink!router eigrp 200redistribute connectedredistribute staticnetwork 172.21.0.0!ip default-gateway 172.21.17.1ip classlessip route 0.0.0.0 0.0.0.0 172.21.17.1!dialer-list 1 protocol ip permitradius-server host 172.31.61.87 auth-port 1645 acct-port 1646radius-server key foobar!endSecondary Network Access Server Configuration Example for NAS2
version 12.0service timestamps debug datetime msecservice timestamps log uptimeservice password-encryption!hostname NAS2!boot system flashaaa new-modelaaa authentication ppp default radius localaaa authorization network default radius noneaaa authorization configuration default radiusenable password 7 022916700202!username NAS1 password 7 104D000A0618username dialbid password 7 070C285F4D06username echo-8.cisco.com password 7 0822455D0A16ip subnet-zeroip domain-name cisco.comip name-server 172.22.30.32ip name-server 172.31.2.132!virtual-profile virtual-template 2!sgbp group dialbidsgbp member NAS1 172.21.17.18sgbp dial-bidsisdn switch-type basic-5ess!interface Ethernet0ip address 172.21.17.17 255.255.255.0no ip directed-broadcastmedia-type 10BaseT!interface Virtual-Template1ip address 1.1.1.1 255.255.255.252no ip directed-broadcast!interface Virtual-Template2ip unnumbered Virtual-Template1no ip directed-broadcastppp multilinkmultilink load-threshold 1 outbound!interface BRI0no ip addressno ip directed-broadcastencapsulation pppdialer rotary-group 0isdn switch-type basic-5essno fair-queue!interface Dialer0ip unnumbered Ethernet0no ip directed-broadcastencapsulation pppdialer in-banddialer dnsdialer aaadialer hold-queue 5dialer congestion-threshold 5dialer reserved-links 1 0dialer-group 1no fair-queueppp authentication chap callinppp multilink!router eigrp 200redistribute connectedredistribute staticnetwork 172.21.0.0!ip default-gateway 172.21.17.1ip classlessip route 0.0.0.0 0.0.0.0 172.21.17.1!dialer-list 1 protocol ip permit!radius-server host 172.31.61.87 auth-port 1645 acct-port 1646radius-server key foobar!endRouter Remote Configuration Example
version 12.0service timestamps debug datetime msecservice timestamps log uptimeservice password-encryptionservice udp-small-serversservice tcp-small-servers!hostname Remote!boot system flashenable password 7 002B012D0D5F!username dialbid password 7 14141B180F0Bip subnet-zerono ip domain-lookup!isdn switch-type basic-5ess!interface Loopback0ip address 172.31.229.41 255.255.255.255no ip directed-broadcastno ip route-cacheno ip mroute-cache!interface Loopback1ip address 20.1.1.1 255.255.255.0no ip directed-broadcastno ip route-cacheno ip mroute-cache!interface Loopback2ip address 20.1.2.1 255.255.255.0no ip directed-broadcastno ip route-cacheno ip mroute-cache!interface Loopback3ip address 40.1.1.1 255.255.255.0no ip directed-broadcastno ip route-cacheno ip mroute-cache!interface Ethernet0ip address 172.21.12.15 255.255.255.0no ip directed-broadcastno ip route-cacheno ip mroute-cache!interface BRI0no ip addressno ip directed-broadcastencapsulation pppno ip route-cacheno ip mroute-cachedialer rotary-group 3dialer-group 1isdn switch-type basic-5essno fair-queue!interface Dialer3ip unnumbered Loopback0no ip directed-broadcastencapsulation pppno ip route-cacheno ip mroute-cachedialer in-banddialer idle-timeout 10000dialer-group 1no fair-queueppp authentication chap callinppp chap hostname echo-8.cisco.comppp chap password 7 045802150C2Eppp multilink!ip default-gateway 172.21.12.1ip classlessip route 0.0.0.0 0.0.0.0 1.1.1.1!dialer-list 1 protocol ip permitSample User Profile on an Ascend RADIUS Server for NAS1
Following is an example of a dialout profile and a static route download profile in AAA. The dialout profile username must have "-out" appended to it. The static route download profile username always has "-N" appended. The router downloads NAS1-1, NAS1-2, through NAS1-N. When NAS1-N fails, the router does not try NAS1-N+1. The static route download profile cannot have more than 50 static routes defined.
echo-8.cisco.com-out Password = "cisco", User-Service-Type = Outbound-Usercisco-avpair = "outbound:addr=172.31.229.41",cisco-avpair = "outbound:dial-number=60039",cisco-avpair = "ip:route=20.1.1.0 255.255.255.0 172.31.229.41",cisco-avpair = "ip:route=20.1.2.0 255.255.255.0 172.31.229.41",cisco-avpair = "ip:route=20.1.3.0 255.255.255.0 172.31.229.41",cisco-avpair = "ip:route=40.1.1.0 255.255.255.0 172.31.229.41",NAS1-1 Password = "cisco" User-Service-Type = Outbound-User,cisco-avpair = "ip:route=20.1.3.0 255.255.255.0 172.31.229.41 200",cisco-avpair = "ip:route=20.1.2.0 255.255.255.0 172.31.229.41 200",cisco-avpair = "ip:route=20.1.1.0 255.255.255.0 172.31.229.41 200",cisco-avpair = "ip:route=172.31.229.41 255.255.255.255 Dialer1 200 nameecho-8.cisco.com"Static routes can also be defined using the Framed-Route IETF standard. The following shows how the above example for NAS1 would look using the Framed-Route IETF standard:
NAS1-1 Password = "cisco" User-Service-Type = Outbound-User,Framed-Route = "20.1.3.0/24 172.31.229.41.200",Framed-Route = "20.1.2.0/24 172.31.229.41.200",Framed-Route = "20.1.1.0/24 172.31.229.41.200",Framed-Route = "172.31.229.41/32 Dialer1 200 name echo-8.cisco.com"Asynchronous Dialing Configuration Examples
Large scale dialout supports dialing out using an asynchronous line. This requires that a chat script be configured, and that the script dialer command be configured in the line commands for any asynchronous interface that may be dialing out. The following examples are provided in this section:
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Asynchronous Dialing Configuration Example
The following is an example of an asynchronous dialing configuration.
chat-script dial "" "ATZ" OK "ATDT\T" TIMEOUT 60 CONNECT!interface Async1no ip addressno ip directed-broadcastencapsulation pppdialer in-banddialer rotary-group 0async dynamic addressasync dynamic routingasync mode dedicatedno cdp enable!interface Dialer0ip address 172.21.30.32 255.255.255.0no ip directed-broadcastencapsulation pppno ip mroute-cachebandwidth 64dialer in-banddialer idle-timeout 60dialer enable-timeout 10dialer hold-queue 50dialer-group 1no cdp enable!line 1script dialer dialmodem InOuttransport input allAsynchronous and Synchronous Dialing Configuration Example
The following example creates a dialer rotary group for the asynchronous interfaces, and a dialer rotary group for the PRI interfaces. Any dialin or dialout reservations are applied only to the PRI dialer interface. In the configuration example below:
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chat-script dial "" "ATZ" OK "ATDT\T" TIMEOUT 60 CONNECT!interface Serial0:23no ip addressno ip directed-broadcastno keepalivedialer rotary-group 1isdn switch-type primary-5essisdn incoming-voice modemno cdp enable!interface Async1no ip addressno ip directed-broadcastencapsulation pppdialer in-banddialer rotary-group 0async dynamic addressasync dynamic routingasync mode dedicatedno cdp enable!interface Dialer0ip address 172.21.30.32 255.255.255.0no ip directed-broadcastencapsulation pppno ip mroute-cachebandwidth 64dialer in-banddialer dnsdialer aaadialer idle-timeout 60dialer enable-timeout 10dialer hold-queue 50dialer-group 1no cdp enable!interface Dialer1ip address unnumbered eth0no ip directed-broadcastdialer in-banddialer dnsdialer aaadialer reserved-links 22 0no cdp enable!line 1script dialer dialmodem InOuttransport input allCommand Reference
This section documents new or modified commands required to configure the large scale dialout feature. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command references.
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aaa authorization configuration default
To download static route configuration information from the AAA server using TACACS+ or RADIUS, use the aaa authorization configuration default command in global configuration mode. To remove static route configuration information, use the no form of this command.
aaa authorization configuration default {radius | tacacs+}
no aaa authorization configuration defaultSyntax Description
Default
No configuration authorization is defined.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
Example
The following example downloads static route information using a TACACS+ server:
router(config)# aaa authorization configuration default tacacs+Related Commands
aaa new-model
aaa route download
clear ip route download
show ip routeaaa route download
To enable the download static route feature and set the amount of time between downloads, use the aaa route download command in global configuration mode. To disable this function, use the no form of the command.
aaa route download [time]
no aaa route downloadSyntax Description
Default
The default period between downloads (updates) is 720 minutes.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
This command is used to download static route details from the AAA server if the name of the router is hostname. The name passed to the AAA server for static routes is hostname-1, hostname-2 .... hostname-n — the router downloads static routes until it fails an index and no more routes can be downloaded.
Example
The following example sets the AAA route update period to 100 minutes:
router(config)# aaa route download 100Related Commands
aaa authorization configuration default
clear ip route download
show ip routeclear dialer sessions
To remove all dialer sessions and disconnect links when connected, use the clear dialer sessions command in EXEC configuration mode.
clear dialer sessions
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
Example
The following example of how to enter the clear dialer sessions command:
router# clear dialer sessionsRelated Commands
show dialer sessions
clear ip route download
To clear static routes downloaded from a AAA server, use the clear ip route download command in EXEC configuration mode.
clear ip route download {* | network-number network-mask | reload}
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
This command forces the router to reload static routes from the AAA server before the update timer expires.
Example
The following example shows how to clear all routes:
router# clear ip route download *Related Commands
aaa authorization configuration default
aaa route download
show ip routedialer aaa
To allow a dialer to access the AAA server for dialing information, use the dialer aaa command in interface configuration mode. To disable this function, use the no form of the command.
dialer aaa
no dialer aaaSyntax Description
This command has no arguments or keywords.
Default
This feature is not enabled by default.
Command Mode
Interface configuration of a dialer rotary group leader.
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
This command is required for large scale dialout functionality. See the section "Define a User Profile" for information about defining AAA elements in a user profile.
Example
The following example shows how to allow a dialer interface access to the AAA server for dialing information:
router(config)# interface Dialer0router(config-if)# dialer aaaRelated Commands
dialer congestion-threshold
To specify congestion threshold in connected links, use the dialer congestion-threshold command in interface configuration mode. To disable this function, use the no form of the command.
dialer congestion-threshold links
no dialer congestion-thresholdSyntax Description
Default
The default number of connected links is 64000.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
This command is used to force the dialer to search for another uncongested system (the alternate network access server) in a stack group to dial out using SGBP.
Example
The following example sets the congestion threshold to five connected links on the Dialer 0 interface:
router(config)# interface Dialer0router(config-if)# dialer aaarouter(config-if)# dialer congestion-threshold 5Related Commands
dialer reserved-links
sgbp dial-bidsdialer dns
To obtain a user profile name on a remote network using reverse DNS, use the dialer dns command in interface configuration mode. Use the no form of this command to disable this function.
dialer dns
no dialer dnsSyntax Description
This command has no arguments or keywords.
Default
The reverse DNS function is disabled by default.
Command Mode
Interface configuration of a dialer rotary group leader.
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
This command allows the dialer to use reverse DNS to get a profile name for accessing the AAA server. This command is not required when using named static routes.
Example
The following example shows how to allow the dialer to use reverse DNS for name lookup:
router(config)# interface Dialer0router(config-if)# dialer aaarouter(config-if)# dialer dnsRelated Commands
dialer reserved-links
To reserve links for dial in and dialout, use the dialer reserved-links command in interface configuration mode.
dialer reserved links {dialin-link | dialout link}
no dialer reserved linksSyntax Description
Default
By default, no links are reserved.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
Example
The following example sets dial in reserved links to 1 and dialout reserved links to 0 on the Dialer0 interface:
router(config)# interface Dialer0router(config-if)# dialer aaarouter(config-if)# dialer reserved-links 1 0Related Commands
dialer congestion-threshold
sgbp dial-bidsip route
To establish static routes and define the next hop for large scale dialout, use the ip route command in global configuration mode. To remove static routes, use the no ip route command.
ip route network-number network-mask {IP address | interface} [distance] [name name]
no ip routeSyntax Description
