Security Configuration Guide: Zone-Based Policy Firewall Cisco IOS Release 15.1M&T

Zone-Based Policy Firewall

This module describes the Cisco IOS unidirectional firewall policy between groups of interfaces known as zones. Prior to the release of Cisco IOS unidirectional firewall policy, Cisco IOS firewalls were configured as an inspect rule only on interfaces. Traffic entering or leaving the configured interface was inspected based on the direction that the inspect rule was applied.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Zone-Based Policy Firewall" section.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

•Prerequisites for Zone-Based Policy Firewall

•Restrictions for Zone-Based Policy Firewall

•Information About Zone-Based Policy Firewall

•How to Configure Zone-Based Policy Firewall

•Configuration Examples for Zone-Based Policy Firewall

•Additional References

•Feature Information for Zone-Based Policy Firewall

Prerequisites for Zone-Based Policy Firewall

•Before you create zones, you must consider what should constitute the zones. The general guideline is that you should group interfaces that are similar when they are viewed from a security perspective.

•The Wide Area Application Services (WAAS) and Cisco IOS firewall interoperability capability applies only on the Cisco IOS Zone-Based Policy Firewall feature in Release 12.4(11)T2 and later releases. The Cisco IOS firewall that preceded Release 12.4(11)T2 does not incorporate the Cisco WAAS interoperability enhancement.

Restrictions for Zone-Based Policy Firewall

•If a configuration includes both security zones and inspect rules on interfaces (the old methodology), the configuration may work, but that type of configuration is not recommend.

•The cumulative counters in the show policy-map type inspect zone-pair command output do not increment for match statements in a nested class-map configuration in Cisco IOS Releases 12.4(20)T and 12.4(15)T. The problem with the counters exists regardless of whether the top level class map uses the match-any or match-all keyword. Refer to the "Example: Protocol Match Data Not Incrementing for a Class Map" section for more information.

•In Cisco IOS Release 12.4(15)T, if Simple Mail Transfer Protocol (SMTP) is configured for inspection in a class map and the inspection of Extended Simple Mail Transfer Protocol (ESMTP) needs to be configured, then the no match protocol smtp command must be entered before adding the match protocol smtp extended command. To revert to regular SMTP inspection, use the no match protocol smtp extended command and then enter the match protocol smtp command.

If these commands are not configured in the proper order in a particular release, then the following error displays:
%Cannot add this filter.Remove match protocol smtp filter and then add this filter

•In a WAAS and Cisco IOS firewall configuration, all packets processed by a Wide Area Application Engine (WAE) device must go over the Cisco IOS firewall in both directions to support the Web Cache Coordination Protocol (WCCP). This situation occurs because the Layer 2 redirect is not available in Release 12.4T. If Layer 2 redirect is configured on the WAE, the system defaults to the generic routing encapsulation (GRE) redirect to continue to function.

•When an in-to-out zone-based policy is configured to match the Internet Control Message Protocol (ICMP) on a Windows system, the traceroute command works. However, the same configuration on an Apple system does not work because it uses a UDP-based traceroute. To overcome this issue, configure an out-to-in zone-based policy with the icmp time-exceeded and icmp host unreachable commands with the pass command (not the inspect command).

•In a WAAS and Cisco IOS firewall configuration, WCCP does not support traffic redirection using policy-based routing (PBR).

•Stateful inspection support for multicast traffic is not supported between any zones, including the self zone. Use Control Plane Policing for protection of the control plane against multicast traffic.

•A UDP-based traceroute is not supported through ICMP inspection.

•To allow GRE and Encapsulating Security Payload (ESP) protocol traffic through a zone-based policy firewall, you must use the pass command. The GRE and ESP protocols do not support stateful inspection. Hence, if you use the inspect command, the traffic for these protocols is dropped.

Information About Zone-Based Policy Firewall

•Top-Level Class Maps and Policy Maps

•Application-Specific Class Maps and Policy Maps

•Overview of Zones

•Security Zones

•Zone Pairs

•Zones and Inspection

•Zones and ACLs

•Zones and VRF-Aware Firewalls

•Zones and Transparent Firewalls

•Overview of Security Zone Firewall Policies

•Class Maps and Policy Maps for Zone-Based Policy Firewalls

•Parameter Maps

•WAAS Support for the Cisco IOS Firewall

•Out-of-Order Packet Processing Support in the Zone-Based Firewall Application

•Intrazone Support in the Zone-Based Firewall Application

Top-Level Class Maps and Policy Maps

Top-level class maps allow you to identify the traffic stream at a high level. This is accomplished by using match access-group and match protocol commands. Top-level class maps are also referred to as Layer 3 and Layer 4 class maps.

Top-level policy maps allow you to define high-level actions by using the inspect, drop, pass, and urlfilter keywords. You can attach the maps to a target (zone pair).

Note Only inspect type policies can be configured on a zone pair.

Application-Specific Class Maps and Policy Maps

Application-specific class maps allow you to identify traffic based on the attributes of a given protocol. All the match conditions in these class maps are specific to an application (for example, HTTP or SMTP). Application-specific class maps are identified by an additional subtype that generally is the protocol name (HTTP or SMTP) in addition to the type inspect.

Application-specific policy maps are used to specify a policy for an application protocol. For example, if you want to drop HTTP traffic with Unique Resource Identifier (URI) lengths exceeding 256 bytes, you must configure an HTTP policy map to do that. Application-specific policy maps cannot be attached directly to a target (zone pair). They must be configured as "child" policies in a top-level Layer 3 or Layer 4 policy map.

Overview of Zones

A zone is a group of interfaces that have similar functions or features. Zones provide a way for you to specify where a Cisco IOS firewall is applied.

For example, on a router, Gigabit Ethernet interface 0/0/0 and Gigabit Ethernet interface 0/0/1 may be connected to the local LAN. These two interfaces are similar because they represent the internal network, so they can be grouped into a zone for firewall configurations.

By default, the traffic between interfaces in the same zone is not subjected to any policy. The traffic passes freely. Firewall zones are used for security features.

Note Zones may not span interfaces in different VPN routing and forwarding (VRF) instances.

When a zone-based policy firewall is enabled for TCP keepalive traffic and the host behind the firewall is undergoing an ungraceful disconnect, TCP keepalive works only when the configured TCP timeout is complete. On receiving an out of window reset (RST) packet, the firewall sends an empty acknowledge (ACK) packet to the initiator of the RST packet. This ACK has the current sequence (SEQ) and ACK number from the firewall session. On receiving this ACK, the client sends an RST packet with the SEQ number that is equal to the ACK number in the ACK packet. The firewall processes this RST packet, clears the firewall session, and passes the RST packet.

Security Zones

A security zone is a group of interfaces to which a policy can be applied.

Grouping interfaces into zones involves two procedures:

•Creating a zone so that interfaces can be attached to it

•Configuring an interface to be a member of a given zone

By default, traffic flows among interfaces that are members of the same zone.

When an interface is a member of a security zone, all traffic to and from that interface (except traffic going to the router or initiated by the router) is dropped. To permit traffic to and from a zone-member interface, you must make that zone part of a zone pair and then apply a policy to that zone pair. If the policy permits traffic (through inspect or pass actions), traffic can flow through the interface.

Basic rules to consider when setting up your zones are as follows:

•Traffic from a zone interface to a nonzone interface or from a nonzone interface to a zone interface is always dropped.

•Traffic between two zone interfaces is inspected if there is a zone pair relationship for each zone and if there is a configured policy for that zone pair.

•By default, all traffic between two interfaces in the same zone is always allowed as if the "pass" action is configured.

•A zone pair can be configured with a zone as both the source and the destination zones. An inspect policy can be configured on this zone pair to inspect or drop the traffic between two interfaces in the same zone.

For traffic to flow among all the interfaces in a router, all the interfaces must be a member of one security zone or another.

It is not necessary for all router interfaces to be members of security zones.

Figure 1 illustrates the following:

•Interfaces E0 and E1 are members of security zone Z1.

•Interface E2 is a member of security zone Z2.

•Interface E3 is not a member of any security zone.

Figure 1 Security Zone Restrictions

The following situations exist:

•The zone pair and policy are configured in the same zone. Traffic flows freely between interfaces E0 and E1 because they are members of the same security zone (Z1).

•If no policies are configured, traffic will not flow between any other interfaces (for example, E0 and E2, E1 and E2, E3 and E1, and E3 and E2).

•Traffic can flow between E0 or E1 and E2 only when an explicit policy permitting traffic is configured between zone Z1 and zone Z2.

•Traffic can never flow between E3 and E0/E1/E2 unless default zones are enabled.

Virtual Interfaces as Members of Security Zones

A virtual template interface is a logical interface configured with generic configuration information for a specific purpose or for configuration common to specific users, plus router-dependent information. The template contains Cisco IOS software interface commands that are applied to virtual access interfaces, as needed. To configure a virtual template interface, use the interface virtual-template command.

Zone member information is acquired from a RADIUS server and then the dynamically created interface is made a member of that zone.

The zone-member security command puts the dynamic interface into the corresponding zone.

Zone Pairs

A zone pair allows you to specify a unidirectional firewall policy between two security zones.

To define a zone pair, use the zone-pair security command. The direction of the traffic is specified by specifying a source and destination zone. The source and destination zones of a zone pair must be security zones.

If desired, you can select the default or self zone as either the source or the destination zone. The self zone is a system-defined zone. It does not have any interfaces as members. A zone pair that includes the self zone, along with the associated policy, applies to traffic directed to the router or traffic generated by the router. It does not apply to traffic through the router.

The most common usage of firewalls is to apply them to traffic through a router, so you usually need at least two zones (that is, you cannot use the self zone).

To permit traffic between zone-member interfaces, you must configure a policy permitting (or inspecting) traffic between that zone and another zone. To attach a firewall policy map to the target zone pair, use the service-policy type inspect command.

Figure 2 shows the application of a firewall policy to traffic flowing from zone Z1 to zone Z2, which means that the ingress interface for the traffic is a member of zone Z1 and the egress interface is a member of zone Z2.

Figure 2 Zone Pairs

If there are two zones and you require policies for traffic going in both directions (from Z1 to Z2 and Z2 to Z1), you must configure two zone pairs (one for each direction).

If a policy is not configured between a pair of zones, traffic is dropped. However, it is not necessary to configure a zone pair and a service policy solely for return traffic. Return traffic is allowed, by default, if a service policy permits the traffic in the forward direction. In Figure 2, it is not mandatory that you configure a zone pair source Z2 destination Z1 solely for allowing return traffic from Z2 to Z1. The service policy on the Z1-Z2 zone pair takes care of it.

Zones and Inspection

Zone-based policy firewalls examine the source and destination zones from the ingress and egress interfaces for a firewall policy. It is not necessary that all traffic flowing to or from an interface be inspected; you can designate that individual flows in a zone pair be inspected through your policy map that you apply across the zone pair. The policy map will contain class maps that specify the individual flows.

You can also configure inspect parameters like TCP thresholds and timeouts on a per-flow basis.

Zones and ACLs

Pinholes are not punched for return traffic in interface access control lists (ACLs).

ACLs applied to interfaces that are members of zones are processed before the policy is applied on the zone pair. So, you must relax interface ACLs when there are policies between zones so that they cannot interfere with the policy firewall traffic.

Zones and VRF-Aware Firewalls

The Cisco IOS firewall is VPN routing and forwarding (VRF)-aware. It handles IP address overlap across different VRFs, separate thresholds and timeouts for VRFs, and so forth. All interfaces in a zone must belong to the same VRF.

However, you should not group interfaces from different VRFs in the same zone because VRFs belong to different entities that typically have their own policies.

You can configure a zone pair between two zones that contain different VRFs, as shown in Figure 3.

When multiple VRFs are configured on a router and an interface provides common services to all the VRFs (for example, internet service), you should place that interface in a separate zone. You can then define policies between the common zone and other zones. (There can be one or more zones per VRF.)

Figure 3 Zones and VRF

In Figure 3, the interface providing common services is a member of the zone "common." All of VRF A is in a single zone, vrf_A. VRF B, which has multiple interfaces, is partitioned into multiple zones vrf_B_1 and vrf_B_2. Zone Z1 does not have VRF interfaces. You can specify policies between each of these zones and the common zone. Additionally, you can specify polices between each of the zones vrf_A, vrf_B_n, and Z1 if VRF route export is configured and the traffic patterns make sense. You can configure a policy between zones vrf_A and vrf_B_1, but be sure that traffic can flow between them.

There is no need to specify the global thresholds and timers on a per-VRF basis. Instead, parameters are supplied to the inspect action through a parameter map.

Zones and Transparent Firewalls

The Cisco IOS firewall supports transparent firewalls where the interfaces are placed in bridging mode and IP firewalling is performed on the bridged traffic.

To configure a transparent firewall, use the bridge command to enable the bridging of a specified protocol in a specified bridge and the zone-member security command to attach an interface to a zone. The bridge command on the interface indicates that the interface is in bridging mode.

A bridged interface can be a member of a zone. In a typical case, the Layer 2 domain is partitioned into zones and a policy is applied the same way as for Layer 3 interfaces.

Transparent Firewall Restriction for P2P Inspection

A Cisco IOS firewall uses network-based application recognition (NBAR) for peer-to-peer (P2P) protocol classification and policy enforcement. NBAR is not available for bridged packets; thus, all P2P packet inspection is not supported for firewalls with transparent bridging.

Overview of Security Zone Firewall Policies

A class is a way of identifying a set of packets based on its contents. Normally you define a class so that you can apply an action on the identified traffic that reflects a policy. A class is designated through class maps.

An action is a specific functionality. It typically is associated with a traffic class. For example, inspect, drop, and pass are actions.

To create firewall policies, you should complete the following tasks:

•Define a match criterion (class map)

•Associate actions to the match criteria (policy map)

•Attach the policy map to a zone pair (service policy)

The class-map command creates a class map to be used for matching packets to a specified class. Packets arriving at the targets (such as the input interface, output interface, or zone pair), determined by how the service-policy command is configured, are checked against the match criteria configured for a class map to determine if the packet belongs to that class.

The policy-map command creates or modifies a policy map that can be attached to one or more targets to specify a service policy. Use the policy-map command to specify the name of the policy map to be created, added to, or modified before you can configure policies for classes whose match criteria are defined in a class map.

Class Maps and Policy Maps for Zone-Based Policy Firewalls

Quality of service (QoS) class maps have numerous match criteria; firewalls have fewer match criteria. Firewall class maps have type inspect; this information controls what shows up under firewall class maps.

A policy is an association of traffic classes and actions. It specifies what actions should be performed on the defined traffic classes. An action is a specific function, and it is typically associated with a traffic class. For example, inspect and drop are actions.

Layer 3 and Layer 4 Class Maps and Policy Maps

Layer 3 and Layer 4 class maps are used to identify traffic streams on which different actions should be performed.

A Layer 3 or Layer 4 policy map is sufficient for the basic inspection of traffic.

The following example shows how to configure class map c1 with the match criteria of ACL 101 and the HTTP protocol, and create an inspect policy map named p1 to specify that packets will be dropped on the traffic at c1:

Router(config)# class-map type inspect match-all c1 

Router(config-cmap)# match access-group 101

Router(config-cmap)# match protocol http 

Router(config)# policy-map type inspect p1 

Router(config-pmap)# class type inspect c1 

Router(config-pmap-c)# drop

To create a Layer 3 or Layer 4 policy, see the "Configuring Layer 7 Protocol-Specific Firewall Policies"section.

Class-Map Configuration Restriction

If traffic meets multiple match criteria, the match criteria must be applied in the order of specific to less specific. For example, consider the following class map example:

class-map type inspect match-any my-test-cmap

 match protocol http

 match protocol tcp

In this example, HTTP traffic must first encounter the match protocol http command to ensure that the traffic will be handled by the service-specific capabilities of HTTP inspection. If the "match" lines were reversed so traffic encountered the match protocol tcp command before it was compared to the match protocol http command, the traffic would simply be classified as TCP traffic and inspected according to the capabilities of the Firewall's TCP Inspection component. This configuration would be a problem for services such as FTP and TFTP, and for several multimedia and voice signaling services such as H.323, Session Initiation Protocol (SIP), Skinny, and RTSP. These services require additional inspection capabilities to recognize their more complex activities.

Rate Limiting (Policing) Traffic Within a Layer 3 and Layer 4 Policy Map

In Cisco IOS Release 12.4(9)T, you can use the police command within an inspect policy to limit the number of concurrent connections allowed for applications such as Instant Messenger and P2P.

To effectively use the police command, you must also enable Cisco IOS stateful packet inspection within the inspect policy map. If you configure the police command without configuring the inspect action (through the inspect command), you will receive an error message and the police command will be rejected.

Compatibility with Existing Police Actions

Police actions provisioned in a modular quality of service (QoS) CLI (MQC) policy map are applied as input and output policies on an interface. An inspect policy map can be applied only to a zone pair, not to an interface. The police action will be enforced on traffic that traverses the zone pair. (The direction is inherent to the specification of the zone pair.) Thus, a QoS policy containing a police action can be present on interfaces that make up a zone pair and a police action can also be present in an inspect policy map applied across the zone pair. If both police actions are configured, the zone pair policer is executed after the input, interface policer, but before the output, interface policer. There is no interaction between the QoS and the inspect policers.

Police Restrictions

•The police action is not allowed in policies that are attached to zone pairs involving a "self" zone. Use Control Plane Policing if you want to perform this task.

•Policing can be specified only in Layer 3 and Layer 4 policy maps; it cannot be specified in Layer 7 policy maps.

Layer 7 Class Maps and Policy Maps

Layer 7 class maps can be used in inspect policy maps only for deep packet inspection (DPI).

To create a Layer 7 class map, use the class-map type inspect command for the desired protocol. For example, for the HTTP protocol you would enter the class-map type inspect http command.

The type of class map (for example, HTTP) determines the match criteria that you can use. For example, if you want to specify HTTP traffic that contains Java applets, you must specify a "match response body java" statement in the context of an "inspect HTTP" class map.

A Layer 7 policy map provides application-level inspection of traffic. The policy map can include class maps only of the same type.

The DPI functionality is delivered through Layer 7 class maps and policy maps.

To create a Layer 7 policy map, specify the protocol in the applicable policy-map type inspect command. For example, to create a Layer 7 HTTP policy map, use the policy-map type inspect http command. In that command there is an argument where you enter the HTTP policy-map name.

If you do not specify a protocol name (for example, you use the policy-map type inspect command), you will be creating a Layer 3 or Layer 4 policy map, which can only be an inspect type policy map.

A Layer 7 policy map must be contained in a Layer 3 or Layer 4 policy map; it cannot be attached directly to a target. To attach a Layer 7 policy map to a top-level policy map, use the service-policy (policy-map) command and specify the application name (that is, HTTP, IMAP, POP3, SMTP, or SUNRPC). The parent class for a Layer 7 policy should have an explicit match criterion that matched only one Layer 7 protocol before the policy is attached.

If the Layer 7 policy map is in a lower level, you must specify the inspect action at the parent level for a Layer 7 policy map.

Layer 7 Supported Protocols

You can create Layer 7 class maps and policy maps for the following protocols:

•America Online (AOL) Instant Messenger (IM) protocol

•eDonkey P2P protocol

•FastTrack traffic P2P protocol

•Gnutella Version 2 traffic P2P protocol

•H.323 VoIP Protocol Version 4

•HTTP—The protocol used by web browsers and web servers to transfer files, such as text and graphic files

•Internet Message Access Protocol (IMAP)—Method of accessing e-mail or bulletin board messages kept on a mail server that can be shared

•I Seek You (ICQ) IM protocol

•Kazaa Version 2 P2P protocol

•MSN Messenger IM protocol

•Post Office Protocol, Version 3 (POP3)—Protocol that client e-mail applications use to retrieve mail from a mail server

•SIP—Session Initiation Protocol (SIP)

•SMTP—Simple Network Management Protocol

•SUNRPC—Sun RPC (Remote Procedure Call)

•Windows Messenger IM Protocol

•Yahoo IM protocol

For information on configuring a Layer 7 class map and policy map (policies), see the "Configuring Layer 7 Protocol-Specific Firewall Policies" section.

Class-Default Class Map

In addition to user-defined classes, a system-defined class map named class-default represents all packets that do not match any of the user-defined classes in a policy. It always is the last class in a policy map.

You can define explicit actions for this group of packets. If you do not configure any actions for class-default in an inspect policy, the default action is drop.

Note For a class-default in an inspect policy, you can configure only drop action or pass action.

The following example shows how to use class-default in a policy map. In this example, HTTP traffic is dropped and the remaining traffic is inspected. Class map c1 is defined for HTTP traffic, and class-default is used for a policy map p1.

Router(config)# class-map type inspect match-all c1 

Router(config-cmap)# match protocol http 

Router(config)# policy-map type inspect p1 

Router(config-pmap)# class type inspect c1 

Router(config-pmap-c)# drop 

Router(config-pmap)# class class-default 

Router(config-pmap-c)# drop 

Hierarchical Policy Maps

A policy can be nested within a policy. A policy that contains a nested policy is called a hierarchical policy.

To create a hierarchical policy, attach a policy directly to a class of traffic. A hierarchical policy contains a child and a parent policy. The child policy is the previously defined policy that is associated with the new policy through the use of the service-policy command. The new policy using the pre existing policy is the parent policy.

Note There can be a maximum of two levels in a hierarchical inspect service policy.

Parameter Maps

A parameter map allows you to specify parameters that control the behavior of actions and match criteria specified under a policy map and a class map, respectively.

There are three types of parameter maps:

•Inspect parameter map

An inspect parameter map is optional. If you do not configure a parameter map, the software uses default parameters. Parameters associated with the inspect action apply to all nested actions (if any). If parameters are specified in both the top and lower levels, those in the lower levels override those in the top levels.

•URL Filter parameter map

A parameter map is required for URL filtering (through the URL Filter action in a Layer 3 or Layer 4 policy map and the URL Filter parameter map).

•Protocol-specific parameter map

A parameter map is required for an Instant Messenger application (Layer 7) policy map.

WAAS Support for the Cisco IOS Firewall

The WAAS firewall software, which was introduced in Cisco IOS Release 12.4(15)T, provides an integrated firewall that optimizes security-compliant WANs and application acceleration solutions with the following benefits:

•Optimizes a WAN through full stateful inspection capabilities

•Simplifies Payment Card Industry (PCI) compliance

•Protects transparent WAN accelerated traffic

•Integrates WAAS networks transparently

•Supports the Network Management Equipment (NME) WAE modules or standalone WAAS device deployment

WAAS has an automatic discovery mechanism that uses TCP options during the initial three-way handshake used to identify WAE devices transparently. After automatic discovery, optimized traffic flows (paths) experience a change in the TCP sequence number to allow endpoints to distinguish between optimized and nonoptimized traffic flows.

Note Paths are synonymous with connections.

WAAS allows the Cisco IOS firewall to automatically discover optimized traffic by enabling the sequence number to change without compromising the stateful Layer 4 inspection of TCP traffic flows that contain internal firewall TCP state variables. These variables are adjusted for the presence of WAE devices.

If the Cisco IOS firewall notices that a traffic flow has successfully completed WAAS automatic discovery, it permits the initial sequence number shift for the traffic flow and maintains the Layer 4 state on the optimized traffic flow.

Note Stateful Layer 7 inspection on the client side can also be performed on nonoptimized traffic.

WAAS Traffic Flow Optimization Deployment Scenarios

The following sections describe three different WAAS traffic flow optimization scenarios for branch office deployments. WAAS traffic flow optimization works with the Cisco IOS firewall feature on a Cisco Integrated Services Router (ISR).

•WAAS Branch Deployment with an Off-Path Device

•WAAS Branch Deployment with an Inline Device

Figure 4 shows an example of an end-to-end WAAS traffic flow optimization with the Cisco IOS firewall. In this particular deployment, an NME-WAE device is on the same router as the Cisco IOS firewall. WCCP is used to redirect traffic for interception.

Figure 4 End-to-End WAAS Optimization Path

WAAS Branch Deployment with an Off-Path Device

A WAE device can be either an NME-WAE that is installed on an ISR as an integrated service engine (as shown in Figure 4) or a standalone WAE device.

Figure 5 shows a WAAS branch deployment that uses WCCP to redirect traffic to an off-path, standalone WAE device for traffic interception. The configuration for this option is the same as the WAAS branch deployment with an NME-WAE.

Figure 5 WAAS Off-Path Branch Deployment

WAAS Branch Deployment with an Inline Device

Figure 6 shows a WAAS branch deployment that has an inline WAE device that is physically in front of the ISR router. Because the WAE device is in front of the router, Layer 7 inspection on the client side is not supported because the Cisco IOS firewall receives WAAS optimized packets.

Figure 6 WAAS Inline Path Branch Deployment

An edge WAAS device with the Cisco IOS firewall is applied at branch office sites that must inspect traffic moving to and from a WAN connection. The Cisco IOS firewall monitors traffic for optimization indicators (TCP options and subsequent TCP sequence number changes) and allows optimized traffic to pass, while still applying Layer 4 stateful inspection and deep packet inspection to all traffic, maintaining security while accommodating WAAS optimization advantages.

Note If the WAE device is in the inline location, the device enters its bypass mode after the automatic discovery process. Although the router is not directly involved in WAAS optimization, the router must be aware that WAAS optimization is applied to the traffic in order to apply the Cisco IOS firewall inspection to network traffic and make allowances for optimization activity if optimization indicators are present.

Out-of-Order Packet Processing Support in the Zone-Based Firewall Application

Out-of-Order (OoO) packet processing support for Common Classification Engine (CCE) firewall application and CCE adoptions of the Intrusion Prevention System (IPS) allows for packets that arrive out of order to be copied and reassembled in the correct order. This enhancement reduces the need to retransmit dropped packets and reduces the bandwidth needed for transmission on a network. To configure OoO support, use the parameter-map type ooo global command.

Note IPS sessions use OoO parameters configured using the parameter-map type ooo global command.

Note OoO processing is not supported in SMTP because SMTP supports masking actions that require packet modification.

OoO packet processing support is enabled by default when a Layer 7 policy is configured for Deep Packet Inspection (DPI) for the following protocols:

•AOL IM protocol

•eDonkey P2P protocol

•FastTrack traffic P2P protocol

•Gnutella Version 2 traffic P2P protocol

•H.323 VoIP Protocol Version 4

•HTTP—The protocol used by web browsers and web servers to transfer files, such as text and graphic files

•IMAP—Method of accessing e-mail or bulletin board messages kept on a mail server that can be shared

•ICQ IM Protocol

•Kazaa Version 2 P2P protocol

•Match Protocol SIP—Match Protocol Session Initiation Protocol (SIP)

•MSN Messenger IM protocol

•POP3—Protocol that client e-mail applications use to retrieve mail from a mail server

•SUNRPC—Sun RPC (Remote Procedure Call)

•Windows Messenger IM Protocol

•Yahoo IM protocol

For information on configuring a Layer 7 class map and policy map (policies), see the "Configuring Layer 7 Protocol-Specific Firewall Policies" section.

Note OoO packets are dropped when Cisco IOS Intrusion Prevention System (IPS) and zone-based firewall with L4 inspection are enabled.

Intrazone Support in the Zone-Based Firewall Application

Intrazone support allows for zone configuration to include users both inside and outside a network. This allows for traffic inspection between users belonging to the same zone but different networks. Before Cisco IOS Release 15.0(1)M, traffic within a zone was allowed to pass uninspected by default. To configure a zone pair definition with the same zone for source and destination, use the zone-pair security command. This allows the functionality of attaching a policy map and inspecting the traffic within the same zone.

How to Configure Zone-Based Policy Firewall

•Configuring Layer 3 and Layer 4 Firewall Policies (required)

•Configuring a Parameter Map (required)

•Configuring OoO Packet Processing Support in the Zone-Based Firewall Applications (optional)

•Configuring Intrazone Support in the Zone-Based Firewall Applications (optional)

•Configuring Layer 7 Protocol-Specific Firewall Policies (optional)

•Creating Security Zones and Zone Pairs, and Attaching a Policy Map to a Zone Pair (required)

•Configuring the Cisco IOS Firewall with WAAS(optional)

Configuring Layer 3 and Layer 4 Firewall Policies

Layer 3 and Layer 4 policies are "top level" policies that are attached to the target (zone pair). Use the following tasks to configure Layer 3 and Layer 4 firewall policies:

•Configuring a Class Map for a Layer 3 and Layer 4 Firewall Policy

•Creating a Policy Map for a Layer 3 and Layer 4 Firewall Policy

Configuring a Class Map for a Layer 3 and Layer 4 Firewall Policy

Use this task to configure a class map for classifying network traffic.

Note You must perform at least one match step from Step 4, 5, or 6.

When packets are matched to an access group, protocol, or class map, a traffic rate is generated for these packets. In a zone-based firewall policy, only the first packet that creates a session matches the policy. Subsequent packets in this flow do not match the filters in the configured policy, but instead match the session directly. The statistics related to subsequent packets are shown as part of the inspect action.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map type inspect [match-any | match-all] class-map-name

4. match access-group {access-group | name access-group-name}

5. match protocol protocol-name [signature]

6. match class-map class-map-name

7. end

8. show policy-map type inspect zone-pair session

Creating a Policy Map for a Layer 3 and Layer 4 Firewall Policy

Use this task to create a policy map for a Layer 3 and Layer 4 firewall policy that will be attached to zone pairs.

Note If you are creating an inspect type policy map, note that only the following actions are allowed: drop, inspect, police, pass, service-policy, and urlfilter.

Note You must perform at least one step from Step 5, 8, 9, or 10.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map type inspect policy-map-name

4. class type inspect class-name

5. inspect [parameter-map-name]

6. police rate bps burst size

7. drop [log]

8. pass

9. service-policy type inspect policy-map-name

10. urlfilter parameter-map-name

11. exit

Configuring a Parameter Map

Depending on your policy, you can configure either an inspect, URL filter, or protocol-specific type parameter map. If you are configuring a URL filter type or protocol-specific type policy, you must configure a parameter map, as appropriate. However, a parameter map is optional if you are using an inspect type policy.

Note Changes to the parameter map are not reflected on connections already established through the firewall. Changes are applicable only to new connections permitted to the firewall. To ensure that your firewall enforces policies strictly, clear all the connections allowed in the firewall after you change the parameter map. To clear existing connections, use the clear zone-pair inspect sessions command.

Use one of the following tasks to configure a parameter map:

•Creating an Inspect Parameter Map

•Creating a URL Filter Parameter Map

•Configuring a Layer 7 Protocol-Specific Parameter Map

Creating an Inspect Parameter Map

Use this task to create an inspect type parameter map.

SUMMARY STEPS

1. enable

2. configure terminal

3. parameter-map type inspect {parameter-map-name | global | default}

4. log {dropped-packets {disable | enable} | summary [flows number] [time-interval seconds]}

5. alert {on | off}

6. audit-trail {on | off}

7. dns-timeout seconds

8. icmp idle-timeout seconds

9. max-incomplete {low | high} number-of-connections

10. one-minute {low | high} number-of-connections

11. sessions maximum sessions

12. tcp finwait-time seconds

13. tcp idle-time seconds

14. tcp max-incomplete host threshold [block-time minutes]

15. tcp synwait-time seconds

16. tcp window-scale-enforcement loose

17. udp idle-time seconds

18. exit

Creating a URL Filter Parameter Map

To create a URL filter parameter map, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. parameter-map type urlfilter parameter-map-name

4. alert {on | off}

5. allow-mode {on | off}

6. audit-trail {on | off}

7. cache number

8. exclusive-domain {deny | permit} domain-name

9. max-request number-of-requests

10. max-resp-pak number-of-requests

11. server vendor {n2h2 | websense} {ip-address | hostname [port port-number]} [outside] [log] [retrans retransmission-count] [timeout seconds]

12. source-interface interface-name

13. exit

Configuring a Layer 7 Protocol-Specific Parameter Map

Use this task to configure a Layer 7, protocol-specific parameter map.

Note Protocol-specific parameter maps can be created only for instant messenger applications (AOL, ICQ, MSN Messenger, Yahoo Messenger, and Windows Messenger).

Prerequisites

To enable name resolution to occur, you must also enable the ip domain name command and the ip name-server command.

SUMMARY STEPS

1. enable

2. configure terminal

3. parameter-map type protocol-info parameter-map-name

4. server {name string [snoop] | ip {ip-address | range ip-address-start ip-address-end}}

DETAILED STEPS

Router(config-profile)# server name 
sdsc.msg.example.com

Troubleshooting Tips

To display details of an IM protocol-specific parameter map, use the show parameter-map type protocol-info command.

Configuring OoO Packet Processing Support in the Zone-Based Firewall Applications

Use this task to configure OoO packet processing support in zone-based firewall applications.

Note If a TCP-based Layer 7 policy is configured for DPI, OoO is enabled by default. Use the parameter-map type ooo global command to configure the OoO packet support parameters or to turn off OoO processing.

SUMMARY STEPS

1. enable

2. configure terminal

3. parameter-map type ooo global

4. tcp reassembly alarm {on | off}

5. tcp reassembly memory limit memory-limit

6. tcp reassembly queue length queue-length

7. tcp reassembly timeout time-limit

8. exit

Note In Cisco IOS 12.4(15)T, OoO processing was enabled for zone-based firewall and Intrusion Prevention Systems (IPS) shared sessions with L4 match as match protocol, TCP match protocol http, or any TCP based L7 expecting packet ordering.

Configuring Intrazone Support in the Zone-Based Firewall Applications

Use this task to configure intrazone support when using a zone-based firewall.

SUMMARY STEPS

1. enable

2. configure terminal

3. zone-pair security zone-pair-name [source source-zone-name destination destination-zone-name]

4. policy-map type inspect policy-map-name

5. class type inspect protocol-type class-map-name

6. exit

Configuring Layer 7 Protocol-Specific Firewall Policies

Configure Layer 7 policy maps if you are interested in extra provisioning for Layer 7 inspection modules. It is not necessary that you configure all of the Layer 7 policy maps.

Use one of the following tasks to configure a Layer 7, protocol-specific firewall policy:

•Configuring an HTTP Firewall Policy (optional)

•Configuring a URL Filter Policy (optional)

•Configuring an IMAP Firewall Policy (optional)

•Configuring an Instant Messenger Policy (optional)

•Configuring a Peer-to-Peer Policy (optional)

•Configuring a POP3 Firewall Policy (optional)

•Configuring an SMTP Firewall Policy (optional)

•Configuring a SUNRPC Firewall Policy (optional)

•Configuring an MSRPC Firewall Policy (optional)

Layer 7 Class Map and Policy Map Restrictions

•DPI class maps for Layer 7 can be used in inspect policy maps of the respective type. For example, class-map type inspect http can only be used only in policy-map type inspect http.

•DPI policies require an inspect action at the parent level.

•A Layer 7 (DPI) policy map must be nested at the second level in a Layer 3 or Layer 4 inspect policy map, whereas a Layer 3 or Layer 4 inspect policy can be attached at the first level. Therefore, a Layer 7 policy map cannot be attached directly to a zone pair.

•If no action is specified in the hierarchical path of an inspect service policy, the packet is dropped. Traffic matching class-default in the top-level policy is dropped if there are no explicit actions configured in class-default. If the traffic does not match any class in a Layer 7 policy, the traffic is not dropped; control returns to the parent policy and subsequent actions (if any) in the parent policy are executed on the packet.

•Layer 7 policy maps include class maps only of the same type.

•You can specify the reset action only for TCP traffic; it resets the TCP connection.

•In Cisco IOS Release 15.1(4)M and later releases, removing a class that has a header with a regular expression from a Layer 7 policy map causes active HTTP sessions to reset. Prior to this change, when a class was removed from a Layer 7 policy map, the router reloaded.

Configuring an HTTP Firewall Policy

Use the following tasks to configure an HTTP firewall policy:

•Configuring an HTTP Firewall Class Map

•Configuring an HTTP Firewall Policy Map

If you want to configure match criteria on the basis of an element within a parameter map, you must configure a parameter map as shown in the task "Creating an Inspect Parameter Map."

You must specify at least one match criterion; otherwise, the firewall policy will not be effective.

Configuring an HTTP Firewall Class Map

Use this task to configure an HTTP firewall class map.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map type inspect http [match-any | match-all] class-map-name

4. match response body java-applet

5. match req-resp protocol violation

6. match req-resp body length {lt | gt} bytes

7. match req-resp header content-type {violation | mismatch | unknown}

8. match {request | response | req-resp} header [header-name] count gt number

9. match {request | response | req-resp} header [header-name] length gt bytes

10. match request {uri | arg} length gt bytes

11. match request method {connect | copy | delete | edit | get | getattribute | getattributenames | getproperties | head | index | lock | mkdir | move | options | post | put | revadd | revlabel | revlog | revnum | save | setattribute | startrev | stoprev | trace | unedit | unlock}

12. match request port-misuse {im | p2p | tunneling | any}

13. match req-resp header transfer-encoding {chunked | compress | deflate | gzip | identity | all}

14. match {request | response | req-resp} header [header-name] regex parameter-map-name

15. match request uri regex parameter-map-name

16. match {request | response | req-resp} body regex parameter-map-name

17. match response status-line regex parameter-map-name

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	class-map type inspect http [match-any | match-all] class-map-name Example: Router(config)# class-map type inspect http http-class	Creates a class map for the HTTP protocol so that you can enter match criteria and enters QoS class- map configuration mode.
Step 4	match response body java-applet Example: Router(config-cmap)# match response body java-applet	(Optional) Identifies Java applets in an HTTP connection.
Step 5	match req-resp protocol violation Example: Router(config-cmap)# match req-resp protocol violation	(Optional) Configures an HTTP class map to allow HTTP messages to pass through the firewall or to reset the TCP connection when HTTP noncompliant traffic is detected.
Step 6	match req-resp body length {lt | gt} bytes Example: Router(config-cmap)# match req-resp body length gt 35000	(Optional) Configures an HTTP class map to use the minimum or maximum message size, in bytes, as a match criterion for permitting or denying HTTP traffic through the firewall. •The number of bytes can be from 0 to 65535.
Step 7	match req-resp header content-type {violation | mismatch | unknown} Example: Router(config-cmap)# match req-resp header content-type mismatch	(Optional) This command configures an HTTP class map based on the content type of HTTP traffic.
Step 8	match {request | response | req-resp} header [header-name] count gt number Example: Router(config-cmap)# match req-resp header count gt 16	(Optional) Configure an HTTP firewall policy to permit or deny HTTP traffic on the basis of request, response, or both request and response messages whose header count does not exceed a maximum number of fields.
Step 9	match {request | response | req-resp} header [header-name] length gt bytes Example: Router(config-cmap)# match response header length gt 50000	(Optional) Permits or denies HTTP traffic based on the length of the HTTP request header. •header-name—Specific line in the header field. If a specific line is defined, only that specific field length will be used as a match criterion. •gt bytes—Maximum number of bytes that can be in the header of the HTTP request. Number of bytes range: 0 to 65535.
Step 10	match request {uri | arg} length gt bytes Example: Router(config-cmap)# match request uri length gt 500	(Optional) Configures an HTTP firewall policy to use the URI or argument length in the request message as a match criterion for permitting or denying HTTP traffic.
Step 11	match request method {connect | copy | delete | edit | get | getattribute | getattributenames | getproperties | head | index | lock | mkdir | move | options | post | put | revadd | revlabel | revlog | revnum | save | setattribute | startrev | stoprev | trace | unedit | unlock} Example: Router(config-cmap)# match request method connect	(Optional) Configures an HTTP firewall policy to use the request methods or the extension methods as a match criterion for permitting or denying HTTP traffic.
Step 12	match request port-misuse {im | p2p | tunneling | any} Example: Router(config-cmap)# match request port-misuse any	(Optional) Identifies applications misusing the HTTP port.
Step 13	match req-resp header transfer-encoding {chunked | compress | deflate | gzip | identity | all} Example: Router(config-cmap)# match req-resp header transfer-encoding compress	(Optional) Permits or denies HTTP traffic according to the specified transfer encoding of the message. •chunked—Encoding format (specified in RFC 2616, Hypertext Transfer Protocol—HTTP/1) in which the body of the message is transferred in a series of chunks; each chunk contains its own size indicator. •compress—Encoding format produced by the UNIX compress utility. •deflate—ZLIB format defined in RFC 1950, ZLIB Compressed Data Format Specification Version 3.3, combined with the deflate compression mechanism described in RFC 1951, DEFLATE Compressed Data Format Specification Version 1.3. •gzip—Encoding format produced by the gzip (GNU zip) program. •identity—Default encoding, which indicates that no encoding has been performed. •all—All of the transfer encoding types.
Step 14	match {request | response | req-resp} header [header-name] regex parameter-map-name Example: Router(config-cmap)# match req-resp header regex non_ascii_regex	(Optional) Configures HTTP firewall policy match criteria on the basis of headers that match the regular expression defined in a parameter map. •HTTP has two regular expression (regex) options. One combines the header keyword, content-type header name, and regex keyword and parameter-map-name argument. The other combines the header keyword and regex keyword and parameter-map-name argument. •If the header and regex keywords are used with the parameter-map-name argument, the parameter map does not require a period and asterisk in front of the parameter-map-name argument. For example, either "html" or ".*html" parameter-map-name argument can be configured. •If the header keyword is used with the content-type header name and regex keyword, then the parameter map name requires a period and asterisk (.*) in front of the parameter-map-name argument. For example, the parameter-map-name argument "html" is expressed as: .*html. Note If the period and asterisk are added in front of "html" (.*html), the parameter-map-name argument works for both HTTP regex options. •The mismatch keyword is valid only for the match response header content-type regex command syntax for messages that need to be matched that have a content-type header name mismatch. Tip It is a good practice to add ".*" to the regex parameter-map-name arguments that are not present at the beginning of a text string.
Step 15	match request uri regex parameter-map-name Example: Router(config-cmap)# match request uri regex uri_regex_cm	(Optional) Configures an HTTP firewall policy to permit or deny HTTP traffic on the basis of request messages whose URI or arguments (parameters) match a defined regular expression.
Step 16	match {request | response | req-resp} body regex parameter-map-name Example: Router(config-cmap)# match response body regex body_regex	(Optional) Configures a list of regular expressions that are to be matched against the body of the request, response, or both the request and response message.
Step 17	match response status-line regex parameter-map-name Example: Router(config-cmap)# match response status-line regex status_line_regex	(Optional) Specifies a list of regular expressions that are to be matched against the status line of a response message.

Configuring an HTTP Firewall Policy Map

Use this task to configure an HTTP firewall policy map.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map type inspect http policy-map-name

4. class-type inspect http http-class-name

5. allow

6. log

7. reset

DETAILED STEPS

Configuring a URL Filter Policy

Use this task to configure a URL filter policy.

SUMMARY STEPS

1. enable

2. configure terminal

3. parameter-map type urlfpolicy {local | n2h2 | websense} parameter-map-name

4. exit

5. class-map type urlfilter {class-map-name | match-any class-map-name | n2h2 {class-map-name | match-any class-map-name} | websense {class-map-name | match-any class-map-name}}

6. exit

7. policy-map type inspect urlfilter policy-map-name

8. service-policy urlfilter policy-map-name

DETAILED STEPS

parameter-map type urlfpolicy {local | n2h2 | 
websense} parameter-map-name

exit

Router(config-profile)# exit

class-map type urlfilter {class-map-name | 
match-any class-map-name | n2h2 {class-map-name 
| match-any class-map-name} | websense 
{class-map-name | match-any class-map-name}}

exit

Router(config-cmap)# exit

policy-map type inspect urlfilter 
policy-map-name

Router(config)# policy-map type inspect 
urlfilter websense-policy

service-policy urlfilter policy-map-name

Router(config)# service-policy urlfilter 
websense-policy

Configuring an IMAP Firewall Policy

Use the following tasks to configure an IMAP firewall policy:

•Configuring an IMAP Class Map

•Configuring an IMAP Policy Map

Configuring an IMAP Class Map

Perform this task to configure an IMAP class map.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip inspect name inspection-name protocol [alert {on | off}] [audit-trail {on | off}] [reset] [secure-login] [timeout seconds]

4. class-map type inspect imap [match-any] class-map-name

5. log

6. match invalid-command

7. match login clear-text

8. exit

DETAILED STEPS

Configuring an IMAP Policy Map

Use this task to configure an IMAP policy map.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map type inspect imap policy-map-name

4. class-type inspect imap imap-class-name

5. log

6. reset

DETAILED STEPS

Configuring an Instant Messenger Policy

Use the following tasks to configure an IM policy:

•Configuring an IM Class Map

•Configuring an IM Policy Map

You can create an IM policy for the following IM applications: America Online (AOL), ICQ, MSN Messenger, Yahoo Messenger, and Windows Messenger.

Configuring an IM Class Map

Use this task to configure a class map for any supported IM application.

SUMMARY STEPS

1. enable

2. configure terminal

3. class map type inspect {aol | msnmsgr | ymsgr | icq | winmsgr} [match-any] class-map-name

4. match service {any | text-chat}

DETAILED STEPS

Configuring an IM Policy Map

Use this task to configure a policy map for any supported IM application.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy map type inspect protocol-name policy-map-name

4. class type inspect {aol | msnmsgr | ymsgr | icq | winmsgr} class-map-name

5. reset

6. log

7. allow

DETAILED STEPS

What to Do Next

If you have not done so already, you must configure an IM-specific parameter map as shown in the task "Configuring a Layer 7 Protocol-Specific Parameter Map."

Configuring a Peer-to-Peer Policy

Use the following tasks to configure a P2P firewall policy:

•Configuring a P2P Class Map

•Configuring a P2P Policy Map

You can create a P2P policy for the following P2P applications: eDonkey, FastTrack, Gnutella, and Kazaa Version 2.

Configuring a P2P Class Map

Use this task to configure a class map for any supported P2P application.

SUMMARY STEPS

1. enable

2. configure terminal

3. class map type inspect {edonkey | fasttrack | gnutella | kazaa2} [match-any] class-map-name

4. match file-transfer [regular-expression]

5. match search-file-name [regular-expression]

6. match text-chat [regular-expression]

DETAILED STEPS

Configuring a P2P Policy Map

Use this task to configure a policy map for any supported P2P application.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy map type inspect p2p policy-map-name

4. class type inspect {edonkey | fasttrack | gnutella | kazaa2} class-map-name

5. reset

6. log

7. allow

Configuring a POP3 Firewall Policy

Use the following tasks to configure a POP3 firewall policy:

•Configuring a POP3 Firewall Class Map

•Configuring a POP3 Firewall Policy Map

Configuring a POP3 Firewall Class Map

Use this task to configure a POP3 firewall class map.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip inspect name inspection-name protocol [alert {on | off}] [audit-trail {on | off}] [reset] [secure-login] [timeout seconds]

4. class-map type inspect pop3 [match-any] class-map-name

5. match invalid-command

6. match login clear-text

DETAILED STEPS

Configuring a POP3 Firewall Policy Map

Use this task to configure a POP3 firewall policy map.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map type inspect pop3 policy-map-name

4. class-type inspect pop3 pop3-class-name

5. log

6. reset

DETAILED STEPS

Configuring an SMTP Firewall Policy

Use these tasks to configure an SMTP firewall policy:

•Configuring an SMTP Firewall Class Map

•Configuring an SMTP Firewall Policy Map

Configuring an SMTP Firewall Class Map

Use this task to configure an SMTP firewall class map.

Note To enable inspection for extended SMTP (ESMTP) in a class map, use the match protocol smtp extended command. See the "Restrictions for Zone-Based Policy Firewall" section for more information on using this command in Cisco IOS Release 12.4(15)T.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map type inspect smtp [match-all | match-any] class-map-name

4. match data-length gt max-data-value

DETAILED STEPS

Configuring an SMTP Firewall Policy Map

Use this task to configure an SMTP firewall policy map.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map type inspect smtp policy-map-name

4. class-type inspect smtp smtp-class-name

5. reset

DETAILED STEPS

Configuring a SUNRPC Firewall Policy

Use these tasks to configure a SUNRPC firewall policy:

•Configuring a SUNRPC Firewall Class Map

•Configuring a SUNRPC Firewall Policy Map

Note If you are inspecting an RPC protocol (that is, you specified the match protocol sunrpc command in the Layer 4 class map), the Layer 7 SUNRPC policy map is required.

Configuring a SUNRPC Firewall Class Map

Use this task to configure a SUNRPC firewall class map.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map type inspect sunrpc [match-any] class-map-name

4. match program-number program-number

DETAILED STEPS

Configuring a SUNRPC Firewall Policy Map

Use this task to configure a SUNRPC firewall policy map.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map type inspect sunrpc policy-map-name

4. class-type inspect sunrpc sunrpc-class-name

5. allow [wait-time minutes]

DETAILED STEPS

Configuring an MSRPC Firewall Policy

Note If you are inspecting an RPC protocol (that is, you specified the match protocol msrpc command in the Layer 4 class map), the Layer 7 Microsoft Remote Procedure Call (MSRPC) policy map is required.

Perform this task to configure an MSRPC firewall policy.

SUMMARY STEPS

1. enable

2. configure terminal

3. parameter-map type protocol-info msrpc parameter-map-name

4. timeout seconds

5. exit

6. class-map type inspect match-any class-map-name

7. match protocol msrpc

8. match protocol msrpc-smb-netbios

9. exit

10. policy-map type inspect policy-map-name

11. class type inspect class-map-name

12. inspect

13. exit

14. class class-default

15. drop

16. exit

17. exit

18. zone security security-zone-name

19. exit

20. zone security security-zone-name

21. exit

22. zone-pair security zone-pair-name source source-zone destination destination-zone

23. service-policy type inspect policy-map-name

24. end

DETAILED STEPS

Creating Security Zones and Zone Pairs, and Attaching a Policy Map to a Zone Pair

You need two security zones to create a zone pair. However, you can create only one security zone and use a system-defined security zone called "self." Note that if you select a self zone, you cannot configure inspect policing.

Use this process to complete the following tasks:

•Create at least one security zone

•Define zone pairs

•Assign interfaces to security zones

•Attach a policy map to a zone pair

Tip Before you create zones, think about what should constitute the zones. The general guideline is that you should group interfaces that are similar when they are viewed from a security perspective.

Security Zone Restrictions

•An interface cannot be part of a zone and legacy inspect policy at the same time.

•An interface can be a member of only one security zone.

•When an interface is a member of a security zone, all traffic to and from that interface is blocked unless you configure an explicit interzone policy on a zone pair involving that zone.

•Traffic cannot flow between an interface that is a member of a security zone and an interface that is not a member of a security zone because a policy can be applied only between two zones.

•For traffic to flow among all the interfaces in a router, all the interfaces must be members of one security zone or another. This is particularly important because after you make an interface a member of a security zone, a policy action (such as inspect or pass) must explicitly allow packets. Otherwise, packets are dropped.

•If an interface on a router cannot be part of a security zone or firewall policy, you may have to put that interface in a security zone and configure a "pass all" policy (that is, a "dummy" policy) between that zone and other zones to which a traffic flow is desired.

•You cannot apply an access control list (ACL) between security zones or on a zone pair.

•An ACL cannot be applied between security zones and zone pairs. Include the ACL configuration in a class map, and use policy maps to drop traffic.

•An ACL on an interface that is a zone member should not be restrictive (strict).

•All interfaces in a security zone must belong to the same virtual routing and forwarding (VRF) instance.

•You can configure policies between security zones whose member interfaces are in separate VRFs. However, traffic may not flow between these VRFs if the configuration does not allow it.

•If traffic does not flow between VRFs (because route-leaking between VRFs is not configured), the policy across the VRFs is not executed. This is a misconfiguration on the routing side, not on the policy side.

•Traffic between interfaces in the same security zone is not subjected to any policy; the traffic passes freely.

•The source and the destination zones in a zone pair must be the type security.

•The same zone cannot be defined as both the source and the destination.

SUMMARY STEPS

1. enable

2. configure terminal

3. zone security zone-name

4. description line-of-description

5. exit

6. zone-pair security zone-pair-name [source source-zone-name | self] destination [self | destination-zone-name]

7. description line-of-description

8. exit

9. interface type number

10. zone-member security zone-name

11. exit

12. zone-pair security zone-pair-name {source source-zone-name | self} destination [self | destination-zone-name]

13. service-policy type inspect policy-map-name

Configuring the Cisco IOS Firewall with WAAS

Use the task in this section to enable Cisco IOS firewall inspection so that WAAS optimization can be discovered.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip wccp service-id

4. ip inspect waas enable

5. class-map type inspect class-name

6. match protocol protocol-name [signature]

7. exit

8. policy-map type inspect policy-map-name

9. class class-default

10. class-map type inspect class-name

11. inspect

12. exit

13. exit

14. zone security zone-name

15. description line-of-description

16. exit

17. zone-pair security zone-pair name [source source-zone-name | self] destination [self | destination-zone-name]

18. description line-of-description

19. exit

20. interface type number

21. description line-of-description

22. zone-member security zone-name

23. ip address ip-address

24. ip wccp {service-id {group-listen | redirect {in | out}} | redirect exclude in | web-cache {group-listen | redirect {in | out}}

25. exit

26. zone-pair security zone-pair-name {source source-zone-name | self} destination [self | destination-zone-name]

27. service-policy type inspect policy-map-name

class class-default

inspect