Cisco Wide Area Application Services Configuration Guide (Software Version 5.5.1)

Creating and Managing IP Access Control Lists for WAAS Devices

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This chapter describes how to use the Wide Area Application Services (WAAS) Central Manager GUI to centrally create and manage Internet Protocol (IP) access control lists (ACLs) for your WAAS devices.

This chapter contains the following sections:

• About IP ACLs for WAAS Devices
• Creating and Managing IP ACLs for WAAS Devices
• List of Extended IP ACL Conditions

Note You must log in to the WAAS Central Manager GUI using an account with admin privileges to view, edit, or create IP ACL configurations.

Note Throughout this chapter, the term WAAS device is used to refer collectively to the WAAS Central Managers and WAEs in your network. The term WAE refers to WAE appliances, WAE Network Modules (the NME-WAE family of devices), and SM-SRE modules running WAAS.

About IP ACLs for WAAS Devices

In a centrally managed WAAS network environment, administrators need to be able to prevent unauthorized access to various devices and services. IP ACLs can filter packets by allowing you to permit or deny IP packets destined for a WAAS device.

The WAAS software supports standard and extended ACLs that allow you to restrict access to a WAAS device. The WAAS software can use the following types of ACLs:

• Interface ACL—Applied on the built-in, port channel, standby, and inline group interfaces. This type of ACL is intended to control management traffic (Telnet, SSH, and Central Manager GUI). The ACL rules apply only to traffic that is destined for the WAE or originates from the WAE, not WCCP transit traffic. Use the ip access-group interface configuration command to apply an interface ACL.
• Interception ACL—Applied globally to the WAAS device. This type of ACL defines what traffic is to be intercepted. Traffic that is permitted by the ACL is intercepted and traffic that is denied by the ACL is passed through the WAE. Use the interception access-list global configuration command to apply an interception ACL. For more information on using interception ACLs, see the “Configuring Interception Access Control Lists” section.
• WCCP ACL—Applied on inbound WCCP redirected traffic to control access between an external server and external clients. The WAE is acting like a firewall. Use the wccp access-list global configuration command to apply a WCCP ACL.
• SNMP ACL—Applied on the SNMP agent to control access to the SNMP agent by an external SNMP server that is polling for SNMP MIBs or SNMP statistics. Use the snmp-server access-list global configuration command to apply an SNMP ACL.
• Transaction-logs flow ACL—Applied on the transaction logging facility to restrict the transactions to be logged. Use the transaction-logs flow access-list global configuration command to apply a transaction log ACL.

The following examples illustrate how interface ACLs can be used in environments that have WAAS devices:

• A WAAS device resides on the customer premises and is managed by a service provider, and the service provider wants to secure the device for its management only.
• A WAAS device is deployed anywhere within the enterprise. As with routers and switches, the administrator wants to limit access to Telnet, SSH, and the WAAS Central Manager GUI to the IT source subnets.

To use ACLs, you must first configure ACLs and then apply them to specific services or interfaces on the WAAS device. The following are some examples of how interface ACLs can be used in various enterprise deployments:

• An application layer proxy firewall with a hardened outside interface has no ports exposed. (“Hardened” means that the interface carefully restricts which ports are available for access primarily for security reasons. Because the interface is outside, many types of attacks are possible.) The WAAS device’s outside address is globally accessible from the Internet, while its inside address is private. The inside interface has an ACL to limit Telnet, SSH, and GUI access.
• A WAE that is using WCCP is positioned on a subnet off the Internet router. Both the WAE and the router must have IP ACLs. IP access lists on routers have the highest priority followed by IP ACLs that are defined on the WAEs.

Note We strongly recommend that you use the WAAS Central Manager GUI instead of the WAAS CLI to centrally configure and apply ACLs to your WAAS devices. For more information, see the “Creating and Managing IP ACLs for WAAS Devices” section.

Creating and Managing IP ACLs for WAAS Devices

This section provides guidelines and an example of how to use the WAAS Central Manager GUI to create and manage IP ACLs for your WAAS devices.

When you create an IP ACL, you should note the following important points:

• IP ACL names must be unique within the device.
• IP ACL names must be limited to 30 characters and contain no white space or special characters.
• Each WAAS Central Manager device can manage up to 50 IP ACLs and a total of 500 conditions per device.
• When the IP ACL name is numeric, numbers 1 through 99 denote standard IP ACLs and numbers 100 through 199 denote extended IP ACLs. IP ACL names that begin with a number cannot contain nonnumeric characters.
• The WAAS Central Manager GUI allows the association of standard IP ACLs with SNMP and WCCP. Any device that attempts to access one of these applications associated with an ACL must be on the list of trusted devices to be allowed access.
• You can associate any previously configured standard IP ACL with SNMP and WCCP; however, you can associate an extended IP ACL only with the WCCP application.
• You can delete an IP ACL, including all conditions and associations with network interfaces and applications, or you can delete only the IP ACL conditions. Deleting all conditions allows you to change the IP ACL type if you choose to do so. The IP ACL entry continues to appear in the IP ACL listing; however, it is in effect nonexistent.
• If you specify an empty ACL for any of the ACL types used by WAAS, it has the effect of permitting all traffic.

To use the WAAS Central Manager GUI to create and modify an IP ACL for a single WAE, associate an IP ACL with an application, and then apply it to an interface on the WAE, follow these steps:

Step 1 From the WAAS Central Manager menu, choose Devices > device-name .

Step 2 Choose Configure > Network > TCP/IP Settings > IP ACL .

The IP ACL window appears. By default, there are no IP ACLs defined for a WAE. The IP ACL window indicates if there are currently no IP ACLs configured for the WAE.

Step 3 Click Add IP ACL on the table heading row.

The IP ACL window appears. Fill in the fields as follows:

• In the Name field, enter a name (for example, test1), observing the naming rules for IP ACLs.

By default, this new IP ACL is created as a standard ACL.

Note IP ACL names must be unique within the device, must be limited to 30 characters, and cannot contain any white spaces or special characters.

• If you want to change this default setting and create this new ACL as an extended ACL, choose Extended from the ACL Type drop-down list.

Step 4 Click OK to save the IP ACL named test1. IP ACLs without any conditions defined do not appear on the individual devices.

Step 5 Add conditions to the standard IP ACL named test1 that you just created:

a. Click the Add IP ACL Condition in the table below.

The IP ACL Condition window appears. (See Figure 9-1.)

Note The number of available fields for creating IP ACL conditions depends on the type of IP ACL that you have created, either standard or extended.

Figure 9-1 Creating a New Condition for an Extended IP ACL Window

b. Enter values for the properties that are enabled for the type of IP ACL that you are creating, as follows:

– To set up conditions for a standard IP ACL, go to Step 6.

– To set up conditions for an extended IP ACL, go to Step 7.

Step 6 Set up conditions for a standard IP ACL:

a. From the drop-down list, choose a purpose ( Permit or Deny ).

b. In the Source IP field, enter the source IP address.

c. In the Source IP Wildcard field, enter a source IP wildcard address.

d. Click OK to save the condition.

IP ACL conditions for the newly created IP ACL and its configured parameters are displayed in the table below.

e. To add another condition to the IP ACL, select it in the above table and click on Add IP ACL Condition. Enter the details of the condition in the window and click OK to save the additional condition.

f. If you want a newly created IP ACL condition to appear in a particular position, select the position and click Insert. The IP ACL condition is placed in the selected position.
To reorder your list of conditions, select the condition (or multiple consecutive conditions) and use the Up or Down arrows. Click Save Moved Rows to commit the changes.
Alternately, you can select one or multiple consecutive conditions and click Move to, to specify the row number where the IP ACL condition should be positioned. This is especially helpful when there are numerous conditions listed in the table. Once you are satisfied with all your entries and the order in which the conditions are listed, click Save Moved Rows to commit the changes.

Note The order of the conditions listed in the WAAS Central Manager GUI becomes the order in which IP ACLs are applied to the device.

Click a column heading to sort by any configured parameter.

Table 9-1 describes the fields in a standard IP ACL.

Step 7 Set up conditions for an extended IP ACL:

a. From the drop-down list, choose a purpose ( Permit or Deny ).

b. From the Extended Type drop-down list, choose Generic , TCP , UDP , or ICMP . (See Table 9-2 .)

After you choose a type of extended IP ACL, various options become available in the GUI, depending on what type you choose.

c. In the fields that are enabled for the chosen type, enter the data. (For more information, see Table 9-4 through Table 9-7.)

d. Click OK to save the condition.

IP ACL conditions for the newly created IP ACL and its configured parameters are displayed in the table below.

e. To add another condition to the IP ACL, select it in the above table and click on Add IP ACL Condition. Enter the details of the condition in the window and click OK to save the additional condition.

f. If you want a newly created IP ACL condition to appear in a particular position, select the position and click Insert. The IP ACL condition is placed in the selected position.
To reorder your list of conditions, select the condition (or multiple consecutive conditions) and use the Up or Down arrows. Click Save Moved Rows to commit the changes.
Alternately you can select one or multiple consecutive conditions and click Move to, to specify the row number where the IP ACL condition should be positioned. This is especially helpful when there are numerous conditions listed in the table. Once you are satisfied with all your entries and the order in which the conditions are listed, click Save Moved Rows to commit the changes.

Note The order of the conditions listed in the WAAS Central Manager GUI becomes the order in which IP ACLs are applied to the device.

Click a column heading to sort by any configured parameter.

Step 8 Modify or delete an individual condition from an IP ACL:

a. Select the name of the IP ACL whose condition you want to modify. A list of all the conditions that are currently applied to the IP ACL appears in the IP ACL Conditions table below. Select the condition and click Edit.

b. To modify the condition, change any allowable field as necessary in the IP ACL Condition window and click OK to save the modifications.

c. To delete the condition, select it and click Delete on the table header.

d. To reorder your list of conditions, use the Up or Down arrows or Move to column outlined in Step 6 f and 7 f above.

Step 9 Associate a standard IP ACL with SNMP or WCCP:

a. Click the Edit icon next to the name of the device for which you want to associate a standard IP ACL with SNMP or WCCP.

b. Choose Configure > Network > TCP/IP Settings > IP ACL Feature Usage . The IP ACL Feature Settings window appears.

c. From the drop-down lists, choose the name of an IP ACL for SNMP or WCCP. (For more details, see Table 9-3 .) If you do not want to associate an IP ACL with one of the applications, choose Do Not Set .

d. Click Submit to save the settings.

Step 10 Apply an IP ACL to an interface:

a. Click the Edit icon next to the name of the device for which you want to apply an IP ACL to an interface on the WAE.

b. Choose Configure > Network > Network Interfaces .

The Network Interfaces window for the device appears. This window displays all the interfaces available on that device.

c. Click the Edit icon next to the name of the interface to which you want to apply an IP ACL. The Network Interface settings window appears.

d. From the Inbound ACL drop-down list at the bottom of the window, choose the name of an IP ACL.

e. From the Outbound ACL drop-down list, choose the name of an ACL.

The only network interface properties that can be altered from the WAAS Central Manager GUI are the inbound and outbound IP ACLs. All other property values are populated from the device database and are read-only in the WAAS Central Manager GUI.

Step 11 Click Submit to save the settings.

Step 12 To use an IP ACL to define the traffic that should be intercepted, see the “Configuring Interception Access Control Lists” section.

Step 13 (Optional) Delete an IP ACL:

a. Click the Edit icon next to the name of the device that has the IP ACL that you want to delete.

b. Choose Configure > Network > TCP/IP Settings > IP ACL .

If you created conditions for the IP ACL, you have two options for deletion:

– Delete ACL —Removes the IP ACL, including all conditions and associations with network interfaces and applications.

– Delete All Conditions —Removes all the conditions, while preserving the IP ACL name.

c. To delete the entire IP ACL and its conditions, select the IP ACL and click Delete. You are prompted to confirm your action. Click OK . The record is deleted.

d. To delete only the conditions, select the condition/ multiple conditions (consecutive or non - consecutive conditions) and click Delete. When you are prompted to confirm your action, click OK . The conditions are deleted.

To define an IP ACL from the CLI, you can use the ip access-list global configuration command, and to apply the IP ACL to an interface on the WAAS device, you can use the ip access-group interface configuration command. To configure the use of an IP ACL for SNMP, you can use the snmp-server access-list global configuration command. To specify an IP ACL that the WAE applies to the inbound WCCP redirected traffic that it receives, you can use the wccp access-list global configuration command. To configure an interception ACL, you can use the interception access-list global configuration command.

List of Extended IP ACL Conditions

When you define a condition for an extended IP ACL, you can specify the Internet protocol to be applied to the condition (as described in Step 7 in the “Creating and Managing IP ACLs for WAAS Devices” section).

The list of extended IP ACL conditions are as follows:

• Generic (See Table 9-4 .)
• TCP (See Table 9-5 .)
• UDP (See Table 9-6 .)
• ICMP (See Table 9-7 .)