Home > Articles > Cisco Network Technology > General Networking > Cisco ASA Authentication, Authorization, and Accounting Network Security Services

Cisco ASA Authentication, Authorization, and Accounting Network Security Services

  • Sample Chapter is provided courtesy of Cisco Press.
  • Date: Jan 28, 2010.

Chapter Description

This chapter provides a detailed explanation of the configuration and troubleshooting of authentication, authorization, and accounting (AAA) network security services that Cisco ASA supports.

Configuring Accounting

To configure accounting on the Cisco ASA via ASDM, complete the following steps. The goal in the following example is to enable accounting for all IP traffic sourced from the 10.10.1.0/24 network and destined to the 10.10.2.0/24 network.

  • step 1. Log in to ASDM and navigate to Configuration > Firewall > AAA Rules.
  • step 2. Click on Add and select Add Accounting Rule.
  • step 3. Select the interface where the accounting rule is to be applied. In this example, the inside interface is used.
  • step 4. Under Action, select Account to enable accounting.
  • step 5. Select the AAA server group from the AAA Server Group pull-down menu. In this example, the previously configured AAA server group called my-radius-group is used.
  • step 6. You can configure the source and destination to define specific traffic traversing the Cisco ASA that is to be used for accounting. Configure the specific source IP address or network under the Source field. By default the any keyword is displayed to enable accounting for all sources. In this example, the source network 10.10.1.0/24 is used.
  • step 7. Configure the specific destination IP address or network under the Destination field. By default, the any keyword is displayed to enable accounting for all sources. In this example, the destination network 10.10.2.0/24 is used.
  • step 8. Select the specific service or protocol in the Service field. In this example, the ip keyword is used to enable accounting for all IP traffic sourced from the 10.10.1.0/24 network and destined to the 10.10.2.0/24 network.
  • step 9. Optionally, you can enter a description for this accounting rule in the Description field.
  • step 10. Click Apply to apply the configuration changes.
  • step 11. Click Save to save the configuration in the Cisco ASA.

To enable accounting via the CLI use the aaa accounting command:

   aaa accounting match access_list_name if_name server_tag
   

Example 6-13 demonstrates how to configure accounting on the Cisco ASA via the CLI.

Example 6-13. Enabling Accounting by Using an ACL to Define Interesting Traffic

New York(config)# access-list 100 permit ip 10.10.1.0 255.255.255.0 10.10.2.0
255.255.255.0
New York(config)# aaa accounting match 100 inside my-radius-group

In Example 6-13, an ACL is configured to enable accounting for all connections initiated from 10.10.1.0/24 to 10.10.2.0/24. The ACL is then applied to the aaa accounting match command. A previously defined AAA server group named my-radius-group is used with this command.

You can also use the aaa accounting include | exclude command options, as demonstrated for the aaa authentication command. The aaa accounting match command makes the include and exclude options obsolete.

RADIUS Accounting

Table 6-6 lists all the RADIUS accounting messages supported by Cisco ASA.

Table 6-6. RADIUS Accounting Messages Supported in the Cisco ASA

Attribute

Applicable Messages

acct-authentic

on, off, start, stop

acct-delay-time

on, off, start, stop

acct-status-type

on, off, start, stop

acct-session-id

start, stop

nas-ip-address

on, off, start, stop

nas-port

on, off, start, stop

user-name

on, off, start, stop

class

start, stop

service type

start, stop

framed-protocol

start, stop

framed-ip-address

start, stop

tunnel-client-endpoint

start, stop

acct-session-time

stop

acct-input-packets

stop

acct-output-packets

stop

acct-input-octets

stop

acct-output-octets

stop

acct-terminate-cause

stop

login-ip-host

on, off, start, stop

login-port

on, off, start, stop

Cisco AV pair (used to send source addr/port and dest addr/port)

on, off, start, stop

isakmp-initiator-ip

on, off, start, stop

isakmp-phase1-id

on, off, start, stop

isakmp-group-id

on, off, start, stop

acct-input-gigawords

stop

acct-output-gigawords

stop

The accounting-on message marks the start of accounting services. Subsequently, to mark the end of accounting services, use the accounting-off message. The start and stop accounting records messages are used to label when a user started a connection to a specific service. These sessions are labeled with their own accounting session IDs.

TACACS+ Accounting

Table 6-7 lists all the TACACS+ accounting messages that Cisco ASA supports.

Table 6-7. TACACS+ Accounting Messages Supported by Cisco ASA

Attribute

Applicable Messages

username (fixed field)

start, stop

port (NAS) (fixed field)

start, stop

remote_address (fixed field)

start, stop

task_id

start, stop

foreign_IP

start, stop

local_IP

start, stop

cmd

start, stop

elapsed_time

stop

bytes_in

stop

bytes_out

stop

Cisco ASA also enables you to configure command accounting, depending on the user's privilege level. Use the following command to enable this feature:

aaa accounting command {privilege level} tacacs_server_tag

Example 6-14 demonstrates how to configure command accounting on the Cisco ASA, depending on the user's privilege level.

Example 6-14. Enabling Command Accounting

New York(config)# aaa accounting command privilege 15 my-tacacs-group

In Example 6-14, the accounting command is enabled for users that execute a privilege level 15 command.

Alternatively, you can configure command accounting via ASDM by navigating to Configuration > Device Management > Users/AAA > AAA Access > Accounting and selecting Enable under the Require Command Accounting for ASA section.

Troubleshooting Administrative Connections to Cisco ASA

You can authenticate administrative connections by using RADIUS, TACACS+, or the Cisco ASA local user database. The following debug commands are available to troubleshoot AAA problems when you are trying to connect to the Cisco ASA for administration:

  • debug aaa—Provides information about the authentication, authorization, or accounting messages generated and received by the Cisco ASA.
  • debug radius—To troubleshoot RADIUS transactions, use this command, which has several options:
    • all—Enables all debug options
    • decode—Shows decoded RADIUS transaction messages
    • session—Provides information about all RADIUS sessions
    • user—Enables you to capture RADIUS transaction information for a specific user connection
  • debug tacacs—To troubleshoot TACACS+ transactions, use this command with either of the following options:
    • session—Provides detailed information about all TACACS+ transactions
    • user—Allows you to capture TACACS+ transaction information for a specific user connection

If you enter debug tacacs without any options, the debug command is enabled with the session option by default. Example 6-15 includes the output of debug tacacs during a successful Telnet authentication.

Example 6-15. Output of debug tacacs During a Successful Telnet Authentication

New York# debug tacacs
 mk_pkt - type: 0x1, session_id: 4
user: user1
 Tacacs packet sent
Sending TACACS Start message. Session id: 4, seq no:1
Received TACACS packet. Session id:4  seq no:2
tacp_procpkt_authen: GETPASS
Authen Message: Password:
mk_pkt - type: 0x1, session_id: 4
mkpkt_continue - response: ***
 Tacacs packet sent
Sending TACACS Continue message. Session id: 4, seq no:3
Received TACACS packet. Session id:4  seq no:4
tacp_procpkt_authen: PASS
TACACS Session finished. Session id: 4, seq no: 3

In Example 6-15, User1 connected to the Cisco ASA via Telnet. The Cisco ASA was configured to perform authentication via an external TACACS+ server. The first highlighted line shows that User1 attempted a connection to the Cisco ASA. The second highlighted line shows the ASA requesting the user's password. The user information is sent to the TACACS+ server and is finally authenticated. The third highlighted line shows that the authentication was successful. Example 6-16 includes the output of debug tacacs during an authentication failure. In this example, the incorrect password was entered by the user and the TACACS+ server failed its authentication.

Example 6-16. Output of debug tacacs During a Failed Authentication Because of Wrong Password

New York# debug tacacs
 mk_pkt - type: 0x1, session_id: 5
 user: user1
 Tacacs packet sent
Sending TACACS Start message. Session id: 5, seq no:1
Received TACACS packet. Session id:5  seq no:2
tacp_procpkt_authen: GETPASS
Authen Message: Password:
mk_pkt - type: 0x1, session_id: 5
mkpkt_continue - response: ***
 Tacacs packet sent
Sending TACACS Continue message. Session id: 5, seq no:3
Received TACACS packet. Session id:5  seq no:4
tacp_procpkt_authen: FAIL
TACACS Session finished. Session id: 5, seq no: 3
The highlighted line in Example 6-22 shows the authentication FAIL message.

In Example 6-17, the TACACS+ server was offline or unreachable.

Example 6-17. Output of debug tacacs While TACACS+ Server Is Unreachable

New York# debug tacacs
mk_pkt - type: 0x1, session_id: 6
 user: user1
Tacacs packet sent                                   
Sending TACACS Start message. Session id: 6, seq no:1
Received TACACS packet. Session id:6  seq no:2
TACACS Request Timed out. Session id: 6, seq no:1
TACACS Session finished. Session id: 6, seq no: 1
mk_pkt - type: 0x1, session_id: 6
user: user1
Tacacs packet sent                                  
Sending TACACS Start message. Session id: 6, seq no:1
Received TACACS packet. Session id:6  seq no:2
TACACS Request Timed out. Session id: 6, seq no:1
TACACS Session finished. Session id: 6, seq no: 1
mk_pkt - type: 0x1, session_id: 6
 user: user1
Tacacs packet sent                                  
Sending TACACS Start message. Session id: 6, seq no:1
Received TACACS packet. Session id:6  seq no:2
TACACS Request Timed out. Session id: 6, seq no:1
TACACS Session finished. Session id: 6, seq no: 1
aaa server host machine not responding

The highlighted lines show how the Cisco ASA attempts to communicate with the TACACS+ server three times and finally finishes all authentication transactions. The show aaa-server command is useful while troubleshooting and monitoring authentication transactions. Example 6-18 includes the output of the show aaa-server command for all TACACS+ transactions.

Example 6-18. Monitoring and Troubleshooting TACACS+ Transactions with the show aaa-server Command

New York# show aaa-server protocol tacacs+
Server Group:    mygroup
Server Protocol: tacacs+
Server Address:  172.18.124.145
Server port:     49
Server status:   ACTIVE, Last transaction at 21:05:43 UTC Fri March 20 2009
Number of pending requests               0
Average round trip time                  43ms
Number of authentication requests       4
Number of authorization requests        0
Number of accounting requests           0
Number of retransmissions               0
Number of accepts                        3
Number of rejects                        1
Number of challenges                     4
Number of malformed responses           0
Number of bad authenticators            0
Number of timeouts                       0
Number of unrecognized responses        0

In Example 6-18, the Cisco ASA processed a total of four authentication requests. Three of those requests were successfully authenticated and one was rejected by the TACACS+ server.

Troubleshooting Firewall Sessions (Cut-Through Proxy)

The techniques to troubleshoot cut-through proxy sessions on Cisco ASA are similar to those mentioned in the previous section. Additionally, the show uauth command can be used to display information about authenticated users and current transactions. Example 6-19 shows the output of this command.

Example 6-19. Output of the show uauth Command

New York# show uauth
                          Current    Most Seen
Authenticated Users       0          0
Authen In Progress        1          3

In Example 6-19, a total of three concurrent authentication requests were processed by the Cisco ASA. One is currently being processed.

Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time.

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Cisco Press products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@ciscopress.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by Cisco Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.ciscopress.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020