LDAP Server State

The LDAP Server State feature enables users to capture information about Lightweight Directory Access Protocol (LDAP) server reachability before a request is sent to the server.

LDAP provides applications with a standard method for accessing and modifying the information stored in a directory. LDAP is integrated into the Cisco software as an authentication, authorization, and accounting (AAA) protocol alongside the existing AAA protocols such as RADIUS, TACACS+, Kerberos, and Diameter.

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Prerequisites for LDAP Server State

The Lightweight Directory Access Protocol (LDAP) server should be marked as DEAD by default to get the exact state of the server and the server group.

Restrictions for LDAP Server State

When configuring a Lightweight Directory Access Protocol (LDAP) server, we assume that the server is in DEAD state and is not reachable. The correct state of the server is obtained after the deadtime (the period during which new authentication requests are not sent to an LDAP server that has failed to respond to a previous request) expiry is reached. Within this time frame, even if the server is reachable, no requests should be sent to the server.

Information About LDAP Server State

Overview of LDAP Server State

The LDAP Server State feature reduces the load on the network if the servers are not reachable and avoids unnecessary processing of retransmits.

The authentication, authorization, and accounting (AAA) servers are used to validate users or subscribers before they access a network. If one of the servers is not reachable, the next configured server specified in the configuration is contacted.

AAA client components make use of the DEAD and ALIVE states to keep track of each server state to handle protocol transactions effectively. If the state is DEAD, the client component applies a default set of policies to users or subscribers and allows them to access the default web content. If the state is ALIVE, the client component gets the actual policies from the Lightweight Directory Access Protocol (LDAP) server.

If the automate-tester command is configured along with the deadtime command, after every deadtime expiry, the AAA test APIs send a dummy bind request packet to the LDAP server.

  • If a bind response is received, the server state is updated as ALIVE and further dummy bind requests are not sent.

  • If a bind response is not received, the server state remains as DEAD and after every deadtime expiry, AAA test APIs send dummy bind request packets to the LDAP server.

If the deadtime command is configured when the server is not reachable, the server state remains DEAD until the deadtime expiry is reached, after which the state changes to ALIVE.


Note

If one of the servers in a server group is ALIVE, the server group is marked as ALIVE.

How to Configure LDAP Server State

Perform this task to enable the server state notification functionality in a Lightweight Directory Access Protocol (LDAP) server. By default, all servers are marked as DEAD during configuration.

Configuring LDAP Server State

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    username user password {0 | 7} password

    4.    aaa new-model

    5.    ldap server name

    6.    deadtime minutes

    7.    automate-tester username name probe-on

    8.    end

    9.    show ldap server


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example: 
    Device> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.
     
    Step 2configure terminal


    Example: 
    Device# configure terminal
     

    Enters global configuration mode.

     
    Step 3username user password {0 | 7} password


    Example: 
    Device(config)# username user1 password 0 pwd1
     

    Configures an unencrypted password that is automatically picked up by the automate-tester command.

     
    Step 4aaa new-model


    Example: 
    Device(config)# aaa new-model
     

    Enables the authentication, authorization, and accounting (AAA ) access control system.

     
    Step 5ldap server name


    Example: 
    Device(config)# ldap server server1
          		Configures a device to use the LDAP protocol and enters LDAP server configuration mode.  
    Step 6deadtime minutes


    Example: 
    Device(config-ldap-server)# deadtime 1
          		Configures the deadtime expiry value (in minutes) for the LDAP server.  
    Step 7automate-tester username name probe-on


    Example: 
    Device(config-ldap-server)# automate-tester username user1 probe-on
          		Assigns the state of the LDAP server as DEAD by default when configured along with the deadtime minutes command.  
    Step 8end


    Example: 
    Device(config-ldap-server)# end
          		Exits LDAP server configuration mode and returns to privileged EXEC mode.  
    Step 9show ldap server


    Example: 
    Device# show ldap server
          		Displays the LDAP server state information and various other counters for the server.  

    Configuration Examples for LDAP Server State

    Example: Configuring LDAP Server State

    Device# configure terminal
Device(config)# username user1 password 0 pwd1
Device(config)# aaa new-model
Device(config)# ldap server server1
Device(config-ldap-server)# deadtime 1
Device(config-ldap-server)# automate-tester username user1 probe-on
Device(config-ldap-server)# end

    The following output is displayed on entering the automate-tester username name probe-on command: 

    *Feb 24 09:14:55.139: LDAP_SERVER 192.0.2.10 Server state is UP

    The following sample output from the show ldap server command shows the Lightweight Directory Access Protocol (LDAP) server state information of server1 server and various other counters for the server. 

    Device# show ldap server server1 summary

Server Information for server1
================================
Server name :server1
Server Address :192.0.2.10
Server listening Port :389
Bind Root-dn :user1
Server mode :Non-Secure
Cipher Suite :0x00
Authentication Seq :Search first. Then Bind/Compare password next
Authentication Procedure:Bind with user password
Request timeout :30
Deadtime in Mins :1
State :ALIVE
No. of active connections :0
---------------------------------

    Additional References for LDAP Server State

    Related Documents

    Related Topic Document Title

    Cisco IOS commands

    Cisco IOS Master Command List, All Releases

    Security commands

    LDAP configuration tasks

    “Configuring LDAP” chapter in AAA LDAP Configuration Guide

    Standards and RFCs

    Standard/RFC Title

    RFC 4511

    Lightweight Directory Access Protocol (LDAP)

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    Feature Information for LDAP Server State

    The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

    Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.
    Table 1 Feature Information for LDAP Server State

    Feature Name

    Releases

    Feature Information

    LDAP Server State

    15.4(2)T

    The LDAP Server State feature enables users to capture information about LDAP server reachability before a request is sent to the server.

    The following commands were introduced or modified: automate-tester, deadtime.