Cisco APIC Layer 4 to Layer 7 Services Deployment Guide, Release 2.2(2)

About Policy-Based Redirect

Cisco Application Centric Infrastructure (ACI) policy-based redirect (PBR) enables provisioning service appliances, such as firewalls or load balancers, as managed or unmanaged nodes without needing a Layer 4 to Layer 7 package. Typical use cases include provisioning service appliances that can be pooled, tailored to application profiles, scaled easily, and have reduced exposure to service outages. PBR simplifies the deployment of service appliances by enabling the provisioning consumer and provider endpoint groups to be all in the same virtual routing and forwarding (VRF) instance. PBR deployment consists of configuring a route redirect policy and a cluster redirect policy, and creating a service graph template that uses the route and cluster redirect policies. After the service graph template is deployed, use the service appliance by enabling endpoint groups to consume the service graph provider endpoint group. This can be further simplified and automated by using vzAny. While performance requirements may dictate provisioning dedicated service appliances, virtual service appliances can also be deployed easily using PBR.

The following figure illustrates the use case of redirecting specific traffic to the firewall:

Figure 1. Use Case: Redirecting Specific Traffic to the Firewall

In this use case, you must create two subjects. The first subject permits HTTP traffic, which then gets redirected to the firewall. After the traffic passes through the firewall, it goes to the Web endpoint. The second subject permits all traffic, which captures traffic that is not redirected by the first subject. This traffic goes directly to the Web endpoint.

The following figure illustrates a sample ACI PBR physical topology:

Figure 2. Sample ACI PBR Physical Topology

The following figure illustrates a sample ACI PBR logical topology:

Figure 3. Sample ACI PBR Logical Topology

While these examples illustrate simple deployments, ACI PBR enables scaling up mixtures of both physical and virtual service appliances for multiple services, such as firewalls and server load balancers.

About Multi-Node Policy-Based Redirect

Multi-node policy-based redirect enhances PBR by supporting up to five function nodes in a single service graph. You can configure which service node connector terminates the traffic and based on this configuration, the source and destination class IDs for the service chain are determined. In the multi-node PBR feature, policy-based redirection can be enabled on the consumer, provider, or both of the service node connectors. It can also be configured for the forward or reverse directions. If the PBR policy is configured on a service node connector, then that connector does not terminate traffic.

About Symmetric Policy-Based Redirect

Symmetric policy-based redirect (PBR) configurations enable provisioning a pool of service appliances so that the consumer and provider endpoint groups traffic is policy-based. The traffic is redirected to one of the service nodes in the pool, depending on the source and destination IP equal-cost multi-path routing (ECMP) prefix hashing.

Note

Symmetric PBR configurations require 9300-EX hardware.

Sample symmetric PBR REST posts are listed below:

Under fvTenant svcCont

<vnsSvcRedirectPol name=“LoadBalancer_pool”>
          <vnsRedirectDest name=“lb1” ip=“1.1.1.1” mac=“00:00:11:22:33:44”/> 
          <vnsRedirectDest name=“lb2” ip=“2.2.2.2” mac=“00:de:ad:be:ef:01”/> 
          <vnsRedirectDest name=“lb3” ip=“3.3.3.3” mac=“00:de:ad:be:ef:02”/> 
</vnsSvcRedirectPol>

<vnsLIfCtx name=“external”> 
          <vnsRsSvcRedirectPol tnVnsSvcRedirectPolName=“LoadBalancer_pool”/> 
          <vnsRsLIfCtxToBD tDn=“uni/tn-solar/bd-fwBD”>
</vnsLIfCtx>

<vnsAbsNode name=“FW” routingMode=“redirect”>

Sample symmetric PBR NX-OS-style CLI commands are listed below.

The following commands under the tenant scope create a service redirect policy:

apic1(config-tenant)# svcredir-pol fw-external
apic1(svcredir-pol)# redir-dest 2.2.2.2 00:11:22:33:44:56

The following commands enable PBR:

apic1(config-tenant)# l4l7 graph FWOnly contract default
apic1(config-graph)# service FW svcredir enable

The following commands set the redirect policy under the device selection policy connector:

apic1(config-service)# connector external
apic1(config-connector)# svcredir-pol tenant solar name fw-external

Policy Based Redirect and Hashing Algorithms

Note

This feature is available in the APIC Release 2.2(3x) release and going forward with APIC Release 3.1(1). It is not supported in APIC Release 3.0(x).

In Cisco APIC, Release 2.2(3x), Policy Based Redirect feature (PBR) supports the following hashing algorithms:

Source IP address
Destination IP address
Source IP address, Destination IP address and Protocol Type (also called, Symmetric) based algorithm was supported in prior releases.

Policy-Based Redirect Resilient Hashing

In symmetric PBR, incoming and return user traffic uses the same PBR node in an ECMP group. If, however, one of the PBR nodes goes down/fails, the existing traffic flows are rehashed to another node. This can cause issues such as existing traffic on the functioning node being load balanced to other PBR nodes that do not have current connection information. If the traffic is traversing a stateful firewall, it can also lead to the connection being reset.

Resilient hashing is the process of mapping traffic flows to physical nodes and avoiding the rehashing of any traffic other than the flows from the failed node. The traffic from the failed node is remapped to a "backup" node. The existing traffic on the "backup" node is not moved.

The image below shows the basic functionality of symmetric PBR with incoming and return user traffic using the same PBR nodes.

The next image shows what occurs when one of the PBR nodes is disabled or fails. The traffic for IP1 is rehashed to the next node and IP2 and IP3's traffic is load balanced to another PBR node. As stated earlier, this could lead to connectivity interruptions or delays if the other PBR nodes do not have the current connection information for IP2 and IP3 traffic.

Figure 5. Disabled/Failed PBR node without resilient hashing

The final image shows how this same use case is addressed when resilient hashing is enabled. Only the user traffic from the disabled/failed node is moved. All other user traffic remains on their respective PBR nodes.

Figure 6. Disabled/Failed PBR node with resilient hashing

If the node returns to service, the traffic flows rehashed from the failed node to the active node are returned to the reactivated node.

Note

Adding or deleting PBR nodes from the ECMP group can cause all the traffic flows to be rehashed.

Enabling Resilient Hashing in L4-L7 Policy-Based Redirect

Before you begin

This task assumes that an L4-L7 Policy Based Redirect policy has been created.

Procedure

Step 1	On the menu bar, choose Tenants > All Tenants.
Step 2	In the Work pane, double-click the tenant's name.
Step 3	In the Navigation pane, choose Tenant *tenant_name* > Policies > Protocol > L4-L7 Policy Based Redirect > *L4-L7_PBR_policy_name* .
Step 4	In the Work pane, check the Resilient Hashing Enabled check box.
Step 5	Click Submit.

About Bypass Action

Prior to Cisco APIC Release 4.1(2), when Threshold Enable is selected when creating a Layer 4 to Layer 7 policy-based redirect, only two options were available: deny action or permit action.

With these two options, in a multi-node policy-based redirect graph, when one node crosses the low threshold, the following action would occur, depending on which of the two options you selected:

deny action: Traffic is dropped at this node.
permit action: Traffic is sent directly to the destination, and the rest of the service chain is skipped.

Beginning with Cisco APIC Release 4.1(2), a new bypass action option is available. With this option, in a multi-node policy-based redirect graph, when one node crosses the low threshold, traffic is still able to proceed through the rest of the service chain that is either up or cannot be bypassed.

The following sections describe how traffic is handled for each of these three options using this example two-node policy-based redirect graph.

When both nodes are up, this two-node policy-based redirect behaves in the following manner:


Source EPG	Destination EPG	Action
100	300	PBR to n1-external
201	300	PBR to n2-external
302	300	permit
300	100	PBR to n2-internal
202	100	PBR to n1-internal
101	100	permit

The following sections describe how the two-node policy-based redirect behaves when the first node goes down, based on the option that you select in the Threshold Down Action field.

deny action

Using the example configuration described above, if you select deny action in the Threshold Down Action field and the first node goes down, the PBR policies that use the first node are updated to "Drop", and communication between the Client EPG and the Web EPG will be dropped, as shown in the following table.


Source EPG	Destination EPG	Action
100	300	Drop
201	300	PBR to n2-external
302	300	permit
300	100	PBR to n2-internal
202	100	Drop
101	100	permit

permit action

Using the example configuration described above, if you select permit action in the Threshold Down Action field and the first node goes down, the PBR policies that use the first node are updated to "Permit". Traffic from the Client EPG to the Web EPG (from 100 to 300) proceeds directly, without the service node. Return traffic from the Web EPG to the Client EPG (from 300 to 100) is redirected to n2-internal, as shown in the following table; however, the second node might drop the packet because it is an asymmetric flow.


Source EPG	Destination EPG	Action
100	300	Permit
201	300	PBR to n2-external
302	300	permit
300	100	PBR to n2-internal
202	100	Permit
101	100	permit

bypass action

Beginning with Cisco APIC Release 4.1(2), if you select the new bypass action option in the Threshold Down Action field and the first node goes down, the PBR policies that use the first node are updated to "PBR to next device". In this case, the following occurs:

Traffic from the Client EPG to the Web EPG (from 100 to 300) is redirected to n2-external.
Return traffic from the Web EPG to the Client EPG (from 300 to 100) is redirected to n2-internal.
Return traffic from n2-external to consumer is set to "Permit".


Source EPG	Destination EPG	Action
100	300	PBR to n2-external
201	300	PBR to n2-external
302	300	permit
300	100	PBR to n2-internal
202	100	Permit
101	100	permit

Guidelines and Limitations

Following are the guidelines and limitations for the bypass action option:

The bypass action option is supported only on new generation ToR switches, which are switch models with "EX", "FX" or "FX2" at the end of the switch name.
The bypass action option is not needed on a one-node service graph. If bypass is configured in such a case, forwarding behavior is the same as permit action.
L3Out EPGs and regular EPGs can be consumer or provider EPGs.
A service node that has NAT enabled cannot be bypassed, as that will break the traffic flow.
The bypass action option is not supported in the following cases:
- Layer 4 to Layer 7 devices in one-arm mode
- Layer 1/Layer 2 PBR nodes
- Remote leaf switches
Do not use the same PBR policy in more than one service graph if bypass action is enabled. Cisco APIC will reject configurations if the same PBR policy with bypass action is used in multiple service graphs. To avoid this, configure different PBR policies that use the same PBR destination IP address, MAC address and Health Group.

Configuring the Threshold Down Action in Layer 4 to Layer 7 Policy-Based Redirect

Before you begin

This task assumes that an Layer 4 to Layer 7 Policy-Based Redirect policy has been created.

Procedure

Step 1	On the menu bar, choose Tenants > All Tenants.
Step 2	In the Work pane, double-click the tenant's name.
Step 3	In the Navigation pane, choose Tenant > `tenant_name` > Policies > Protocol > L4-L7 Policy Based Redirect > `L4-L7_PBR_policy_name` .
Step 4	In the Destination Type field, select L3.
Step 5	In the IP SLA Monitoring Policy field, select an existing policy or create a new IP SLA monitoring policy. For more information on creating a new IP SLA monitoring policy, see Configuring IP SLA Monitoring Policy Using the GUI.
Step 6	Check the Threshold Enable check box. The following fields appear: Min Threshold Percent (percentage) Max Threshold Percent (percentage) Threshold Down Action
Step 7	Select the minimum and maximum threshold percentage. For more information on the minimum and maximum thresholds, see Threshold Settings.
Step 8	In the Threshold Down Action area, select the threshold down action. The options are: bypass action deny action permit action
Step 9	Click Submit.

About Policy-Based Redirect with L3Out

Prior to Cisco APIC Release 4.1(2), if policy-based redirect is enabled on a node, both the consumer and the provider connectors of the node must be in bridge domains, as shown in the following illustration, even though the policy-based redirect is not required on an interface.

Beginning with Cisco APIC Release 4.1(2), uni-directional policy-based redirect with L3Out is now supported, as shown in the following illustration. In this example, policy-based redirect is enabled in the bridge domain in the consumer connector, but the policy-based redirect is not enabled on the provider connector in the L3Out.

Configuring Policy-Based Redirect with L3Out

The configuration steps for policy-based redirect with L3Out is essentially the same as a typical policy-based redirect configuration. It is assumed that you already have the necessary tenant, VRF, EPGs, and bridge domains for the EPGs and service bridge domains configured.

Create a Layer 4 to Layer 7 device. For the concrete interface, the path should match with the VLAN used in the L3Out logical interface.
Create a Service Graph template.
Create a PBR policy.
Create an L3Out.
Create a Device Selection Policy using the following settings:
- Enable the PBR on the consumer connector and select the L3Out on the provider connector.
- Deselect the L3 Destination (VIP) field (remove the check from the checkbox) on both the consumer and provider connector for the node with L3Out.
For example, you would make the following selections in the Logical Interface Connector page for each connector:
- On the consumer side, in the Associated Network field, select Bridge Domain and enable PBR in the L4-L7 Policy-Based Redirect field. Also deselect the L3 Destination (VIP) field.
- On the provider side, in the Associated Network field, select L3 External Network and select the L3Out in the L3 External Network field. Also deselect the L3 Destination (VIP) field.
Apply the Service Graph, where you attach the Service Graph to the contract.

Note that you can configure QoS as part of the L3Out configuration.

Example Use Case for Policy-Based Redirect with L3Out

An example situation where policy-based redirect with L3Out would be useful would be a configuration with symmetric PBR with multiple network address translation (NAT) devices, as shown in the following figure.

In this situation, for internal to external traffic, symmetric PBR is used to load balance traffic to one of the PBR nodes. In addition, the IP address from the NAT-pool is outside of the service bridge domain subnet range. The return traffic will go back to the same node in this situation, but for releases prior to Cisco APIC Release 4.1(2), the L3Out cannot be used on the NAT-external side because if the PBR is used on the service node, the other service node connector must be in the bridge domain as well.

However, beginning with Cisco APIC Release 4.1(2), support is available for enabling PBR on the consumer connector, with the provider connector as an L3Out, as shown in the following figure.

Guidelines and Limitations

Following are the guidelines and limitations for policy-based redirect with L3Out:

Use a specific L3Out EPG subnet if there are other L3Out EPGs in the same VRF; otherwise, the other L3Outs might be used by mistake.
Ensure that IP translation occurs on the service node. If the SNAT is not properly done on the firewall, it could be classified to the L3Out internal and could cause a loop.
L3Out is supported only on the provider side of the last node.

PBR Support for Service Nodes in Consumer and Provider Bridge Domains

Starting with the Cisco APIC 3.1(1) release, bridge domains (BDs) that contain a consumer or provider also support service nodes. Therefore, you are not required to provision separate PBR bridge domains any longer.

The Cisco Nexus 9300-EX and 9300-FX platform leaf switches support this feature.

Guidelines and Limitations for Configuring Policy-Based Redirect

Observe the following guidelines and limitations when planning policy-based redirect service nodes:

Select the same action for both service legs. In other words, if you select the deny action for the internal service leg, you should also select the deny action for the external service leg.
L3Out EPGs and regular EPGs can be consumer or provider EPGs.
For a Cold Standby active/standby deployment, configure the service nodes with the MAC address of the active deployment. In a Cold Standby active/standby deployment, when the active node goes down, the standby node takes over the MAC address of active node.
The next-hop service node IP address and virtual MAC address must be provided.
The policy-based redirect bridge domain must have the endpoint dataplane learning disabled.
Provision service appliances in a separate bridge domain. Starting with the Cisco Application Policy Infrastructure Controller (Cisco APIC) release 3.1(x), it is not mandatory to provision service appliances in a separate bridge domain. To support this, Cisco Nexus 9300-EX and 9300-FX platform leaf switches are required.
When downgrading from the Cisco APIC release 3.1 software, an internal code checks whether the policy-based redirect bridge domain uses the same bridge domain as a consumer or a provider. If it does, then the fault is disabled during the downgrade as such a configuration is not supported in earlier Cisco APIC versions.
The service appliance, source, and bridge domain can be in the same VRF.
For Cisco N9K-93128TX, N9K-9396PX, N9K-9396TX, N9K-9372PX, and N9K-9372TX switches, the service appliance must not be in the same leaf switch as either the source or destination endpoint group. For Cisco N9K-C93180YC-EX and N9K-93108TC-EX switches, the service appliance can be in the same leaf switch as either the source or destination endpoint group.
The service appliance can only be in a regular bridge domain.
The contract offered by the service appliance provider endpoint group can be configured to allow-all, but traffic should be routed by the Cisco Application Centric Infrastructure (Cisco ACI) fabric.
Starting with Cisco APIC release 3.1(1), if you use the Cisco Nexus 9300-EX and 9300-FX platform leaf switches, it is not necessary for you to have the endpoint dataplane learning disabled on policy-based redirect bridge domains. During service graph deployment, the endpoint dataplane learning will be automatically disabled only for policy-based redirect node EPG. If you use non-EX and non-FX platform leaf switches, you must have the endpoint dataplane learning disabled on policy-based redirect bridge domains.
Multi-node policy-based redirect (multi-node PBR):
- Supports up to five function nodes in a service graph that can be configured for policy-based redirect.
- Multi-node PBR Layer 3 destination guidelines for load balancers:
  - Layer 3 destination upgrade: The Layer 3 destination (VIP) parameter is enabled by default after the upgrade. No issues will occur from this because if the PBR policy was not configured on a specific service node (pre-3.2(1)), the node connector was treated as an Layer 3 destination and will continue to be in the new Cisco APIC version.
  - Traffic does not always need to be destined to only consumer/provider
  - In the forward direction, the traffic is destined to load balancer VIP
  - In the reverse direction, if SNAT is enabled, the traffic is destined to the load balancer’s internal leg
  - In both directions, enable (check) Layer 3 destination (VIP) on the Logical Interface Context
  - Enable (check) Layer 3 destination (VIP) in both directions to allow you to switch from SNAT to No-SNAT on the load balancer internal by configuring the PBR policy on the internal side
  - If SNAT is disabled:
    - Reverse direction traffic is destined to consumer but not to load balancer internal leg (enable PBR policy on the internal leg)
    - Layer 3 destination (VIP) is not applicable in this case because a PBR policy is applied
Multicast and broadcast traffic redirection is not supported.
Redirection to transparent services is not supported.
If you change a redirect policy's destination to a different group, the Cisco APIC raises a fault due to the change and the policy's operational status becomes disabled. You must clear the fault to re-enable the policy.
Supported policy-based redirect configurations in the same VRF instance include the following:

Figure 7. Supported Policy-based Redirect Configurations in the Same VRF Instance
Supported policy-based redirect configurations in a different VRF instance include the following:

Figure 8. Supported Policy-based Redirect Configurations in a Different VRF Instance
Unsupported policy-based redirect configurations include the following:

Figure 9. Unsupported Policy-based Redirect Configurations

Configuring Policy-Based Redirect Using the GUI

The following procedure configures policy-based redirect (PBR) using the GUI.

Note

The policy-based redirect feature is referred to as "policy-based routing" in the GUI.

Procedure

Step 1

On the menu bar, choose Tenants > All Tenants.

Step 2

In the Work pane, double click the tenant's name.

Step 3

In the Navigation pane, choose Tenant tenant_name > Services > L4-L7 > Devices.

Step 4

In the Work pane, choose Actions > Create L4-L7 Devices.

Step 5

In the Create L4-L7 Devices dialog box, complete the fields as required.

In the General section, the Service Type can be Firewall or ADC.

Note

For L1/L2 PBR configuration, create the L4-L7 device in Unmanaged mode, and perform the following steps:

Select the Service Type as Other.
Select the Device Type Physical (cloud/virtual is not supported).
Select a physical domain.
Select the Function Type L1 or L2 as required.
Create external and internal concrete interfaces and port connectivity on the corresponding leafs.

Create Cluster interfaces by selecting the previously created concrete interfaces (leave VLAN encapsulation blank for dynamic assignments).

Note

For static VLAN configuration, ensure external and internal legs have a different VLAN for L2, otherwise it is the same VLAN for L1.

Step 6

In the Navigation pane, choose Tenant tenant_name > Services > L4-L7 > Service Graph Templates.

Step 7

In the Work pane, choose Action > Create L4-L7 Service Graph Template.

Step 8

In the Create L4-L7 Service Graph Template dialog box, perform the following actions:

In the Graph Name field, enter a name for the service graph template.
For the Graph Type radio buttons, click Create A New Graph.
Drag and drop the device that you created from the Device Clusters pane to between the consumer endpoint group and provider endpoint group. This creates the service node.

As of APIC Release 4.2(1), you can optionally repeat step c to include up to five (5) service nodes.
Select the following based on the service type of the device:
For Firewall, select Routed and continue with the steps below. For ADC, select One-Arm or Two-Arm and continue with the steps below.
In the Profile drop-down list, select a function profile appropriate to the device. If no profiles exist, create one by following the instruction in the Creating a Function Profile Using the GUI.
Select the Route Redirect checkbox.
Click Submit.

The new service graph template appears in the Service Graph Templates table.

Step 9

In the Navigation pane, choose Tenant tenant_name > Policies > Protocol > L4-L7 Policy Based Redirect.

Step 10

In the Work pane, choose Action > Create L4-L7 Policy Based Redirect.

Step 11

In the Create L4-L7 Policy Based Redirect dialog box, complete the fields as required. This policy-based redirect policy is for the consumer connector.

Step 12

Create another policy-based redirect policy for the provider connector.

Step 13

In the Navigation pane, choose Tenant tenant_name > Services > L4-L7 > Service Graph Templates > service_graph_template_name .

Choose the service graph template that you just created.

Step 14

Right click the service graph template and choose Apply L4-L7 Service Graph Template.

Step 15

In the Apply L4-L7 Service Graph Template to EPGs dialog box, perform the following actions:

In the Consumer EPG/External Network drop-down list, choose the consumer endpoint group.
In the Provider EPG/External Network drop-down list, choose the provider endpoint group.
For the Contract radio buttons, click Create A New Contract.
In the Contract Name field, enter a name for the contract.
Do not put a check in the No Filter (Allow All Traffic) check box.
On the Filter Entries table, click + to add an entry.
For the new filter entry, enter "IP" for the name, choose IP for the Ether Type, and click Update.
Click Next.
For the Consumer Connector BD drop-down list, choose the external bridge domain that connects to the consumer endpoint group. Select No for IP Data-plane Learning.
For the Consumer Connector Redirect Policy drop-down list, choose the redirect policy that you created for the consumer connector.
For the Consumer Connector Cluster Interface drop-down list, choose the consumer cluster interface.
For the Provider Connector BD drop-down list, choose the internal bridge domain that connects to the provider endpoint group. Select No for IP Data-plane Learning.
For the Provider Connector Redirect Policy drop-down list, choose the redirect policy that you created for the provider connector.
For the Provider Connector Cluster Interface drop-down list, choose the provider cluster interface.
Click Next.
Configure the parameters as necessary for the device.
Cick Finish.

Configuring Policy-Based Redirect Using the NX-OS-Style CLI

The example commands in this procedure include the route redirect, the cluster redirect, and the graph deployment. The device is created under tenant T1. The device is a Cisco ASA virtual device in managed mode; only unmanaged mode devices can be configured using the CLI.

Procedure

Step 1	Create the device cluster. Example: l4l7 cluster name ifav-asa-vm-ha type virtual vlan-domain ACIVswitch service FW function go-to cluster-device Device2 vcenter ifav108-vcenter vm "ASAv_HA1" cluster-device Device1 vcenter ifav108-vcenter vm "ASAv_HA" cluster-interface provider member device Device1 device-interface GigabitEthernet0/1 interface ethernet 1/45 leaf 102 vnic "Network adapter 3" exit member device Device2 device-interface GigabitEthernet0/1 interface ethernet 1/45 leaf 102 vnic "Network adapter 3" exit exit cluster-interface failover_link member device Device1 device-interface GigabitEthernet0/8 interface ethernet 1/45 leaf 102 vnic "Network adapter 10" exit member device Device2 device-interface GigabitEthernet0/8 interface ethernet 1/45 leaf 102 vnic "Network adapter 10" exit exit cluster-interface consumer member device Device1 device-interface GigabitEthernet0/0 interface ethernet 1/45 leaf 102 vnic "Network adapter 2" exit member device Device2 device-interface GigabitEthernet0/0 interface ethernet 1/45 leaf 102 vnic "Network adapter 2" exit exit exit exit
Step 2	Under tenant PBRv6_ASA_HA_Mode, deploy the PBR service graph instance. Example: `tenant PBRv6_ASA_HA_Mode access-list Contract_PBRv6_ASA_HA_Mode_Filter match ip exit`
Step 3	Create a contract for PBR with the filter match IP protocol. Under the subject, specify the Layer 4 to Layer 7 service graph name. The contract offered by the service appliance provider endpoint group cannot be configured with the `allow-all` setting. Example: `contract Contract_PBRv6_ASA_HA_Mode scope tenant subject Subject access-group Contract_PBRv6_ASA_HA_Mode_Filter both l4l7 graph PBRv6_ASA_HA_Mode_Graph exit exit vrf context CTX1 exit vrf context CTX2 exit`
Step 4	Create a bridge domain for the client and server endpoint group. Both the client and server are in the same VRF instance. Example: `bridge-domain BD1 arp flooding l2-unknown-unicast flood vrf member CTX1 exit bridge-domain BD2 arp flooding l2-unknown-unicast flood vrf member CTX1 exit`
Step 5	Create a separate bridge domain for the external and internal leg of the firewall. PBR requires the learning of the source VTEP on remote leaf switches to be disabled, which is done using the no ip learning command. Example: `bridge-domain External-BD3 arp flooding no ip learning l2-unknown-unicast flood vrf member CTX1 exit bridge-domain Internal-BD4 arp flooding no ip learning l2-unknown-unicast flood vrf member CTX1 exit`
Step 6	Create the application profile and specify the endpoint groups. Example: `application AP1 epg ClientEPG bridge-domain member BD1 contract consumer Contract_PBRv6_ASA_HA_Mode exit epg ServerEPG bridge-domain member BD2 contract provider Contract_PBRv6_ASA_HA_Mode exit exit`
Step 7	Specify the default gateway for the bridge domains. Example: `interface bridge-domain BD1 ipv6 address 89:1:1:1::64/64 exit interface bridge-domain BD2 ipv6 address 99:1:1:1::64/64 exit interface bridge-domain External-BD3 ipv6 address 10:1:1:1::64/64 exit interface bridge-domain Internal-BD4 ipv6 address 20:1:1:1::64/64 exit`
Step 8	Import the device from tenant T1. Example: `l4l7 cluster import-from T1 device-cluster ifav-asa-vm-ha`
Step 9	Create the service graph using the service redirect policy. Example: l4l7 graph PBRv6_ASA_HA_Mode_Graph contract Contract_PBRv6_ASA_HA_Mode service N2 device-cluster-tenant T1 device-cluster ifav-asa-vm-ha mode FW_ROUTED svcredir enable connector consumer cluster-interface consumer_PBRv6 bridge-domain tenant PBRv6_ASA_HA_Mode name External-BD3 svcredir-pol tenant PBRv6_ASA_HA_Mode name External_leg exit connector provider cluster-interface provider_PBRv6 bridge-domain tenant PBRv6_ASA_HA_Mode name Internal-BD4 svcredir-pol tenant PBRv6_ASA_HA_Mode name Internal_leg exit exit connection C1 terminal consumer service N2 connector consumer connection C2 terminal provider service N2 connector provider exit
Step 10	Create the service redirect policy for the external and internal legs. IPv6 addresses are used in this example; you can also specify IPv4 addresses using the same command. Example: `svcredir-pol Internal_leg redir-dest 20:1:1:1::1 00:00:AB:CD:00:11 exit svcredir-pol External_leg redir-dest 10:1:1:1::1 00:00:AB:CD:00:09 exit exit`

Verifying a Policy-Based Redirect Configuration Using the NX-OS-Style CLI

After you have configured policy-based redirect, you can verify the configuration using the NX-OS-style CLI.

Procedure

Step 1

Show the running configuration of the tenant.

Example:

apic1# show running-config tenant PBRv6_ASA_HA_Mode svcredir-pol
# Command: show running-config tenant PBRv6_ASA_HA_Mode svcredir-pol
# Time: Wed May 25 00:57:22 2016
  tenant PBRv6_ASA_HA_Mode
    svcredir-pol Internal_leg
      redir-dest 20:1:1:1::1/32 00:00:AB:CD:00:11
      exit
    svcredir-pol External_leg
      redir-dest 10:1:1:1::1/32 00:00:AB:CD:00:09
      exit
    exit

Step 2

Show the running configuration of the tenant and its service graph.

Example:

apic1# show running-config tenant PBRv6_ASA_HA_Mode l4l7 graph PBRv6_ASA_HA_Mode_Graph
# Command: show running-config tenant PBRv6_ASA_HA_Mode l4l7 graph PBRv6_ASA_HA_Mode_Graph     
# Time: Wed May 25 00:55:09 2016                                                               
  tenant PBRv6_ASA_HA_Mode                                                                     
    l4l7 graph PBRv6_ASA_HA_Mode_Graph contract Contract_PBRv6_ASA_HA_Mode                     
      service N2 device-cluster-tenant T1 device-cluster ifav-asa-vm-ha mode FW_ROUTED svcredir enable
        connector consumer cluster-interface consumer_PBRv6                                           
          bridge-domain tenant PBRv6_ASA_HA_Mode name External-BD3                                    
          svcredir-pol tenant PBRv6_ASA_HA_Mode name External_leg                                     
          exit                                                                                        
        connector provider cluster-interface provider_PBRv6                                           
          bridge-domain tenant PBRv6_ASA_HA_Mode name Internal-BD4
          svcredir-pol tenant PBRv6_ASA_HA_Mode name Internal_leg
          exit
        exit
      connection C1 terminal consumer service N2 connector consumer
      connection C2 terminal provider service N2 connector provider
      exit
    exit

Step 3

Show the service graph configuration.

Example:

apic1# show l4l7-graph graph PBRv6_ASA_HA_Mode_Graph
Graph           : PBRv6_ASA_HA_Mode-PBRv6_ASA_HA_Mode_Graph
Graph Instances : 1

Consumer EPg     : PBRv6_ASA_HA_Mode-ClientEPG
Provider EPg     : PBRv6_ASA_HA_Mode-ServerEPG
Contract Name    : PBRv6_ASA_HA_Mode-Contract_PBRv6_ASA_HA_Mode
Config status    : applied
Service Redirect : enabled

Function Node Name : N2
 Connector   Encap       Bridge-Domain  Device Interface      Service Redirect Policy
 ----------  ----------  ----------     --------------------  -----------------------
 consumer    vlan-241    PBRv6_ASA_HA_  consumer_PBRv6        External_leg
                         Mode-
                         External-BD3
 provider    vlan-105    PBRv6_ASA_HA_  provider_PBRv6        Internal_leg
                         Mode-
                         Internal-BD4

About Layer 1/ Layer 2 Policy-Based Redirect

Prior to ACI release 4.1, you could only deploy a L4-L7 device operating in Layer 1 or Layer 2 mode by using Service Graph and defining the L4-L7 device in Go-Through mode.

Starting with ACI release 4.1, you can deploy a L4-L7 device operating in Layer 1 / Layer 2 mode with Service Graph PBR also.

Starting from APIC release 4.1, PBR can be configured to redirect traffic to a L4-L7 device configured in Layer 1/ Layer 2 device mode as well.

As part of L1/L2 PBR feature, APIC can verify whether the L4-L7 device is forwarding traffic by using L2 Ping packets for link layer tracking.

The advantages compared to configuring a Service Graph with a L4-L7 device in Go-Through mode with Layer 1 / Layer 2 PBR are that you don’t need to create two bridge domains to insert a L4-L7 device between endpoints in the same subnet, hence the configuration is simplified and there are less risks to introduce loops by bridging Bridge Domains.

Differently from Go-Through mode, which can forward also non-IP traffic, Layer 1 / Layer 2 PBR can only forward IP-packets.

The following list summarizes some of the key Layer 1 / Layer 2 PBR configuration concepts:

Deploying a L4-L7 device with Layer 1/ Layer 2 PBR requires the configuration of two service bridge domains, one for the consumer-side and one for the provider-side, unlike regular PBR, these bridge domains cannot be the same as the bridge domains where the endpoints (clients or servers) are configured.
The service bridge domains must be configured for routing.
The physical L4-L7 device can be connected with individual links or with vPC to the leaf switches.
With a Layer 1 device, the consumer side VLAN and the provider side VLAN are the same but on different bridge domains, hence the consumer and provider-side of the L4-L7 device must be on different physical leafs.
When the L4-L7 device is configured as a Layer 1 or Layer 2 device, it doesn’t have an IP address on the interface where it receives and sends traffic, hence the redirect policy is defined by entering the leaf/port and VLAN where it is connected to.
The redirect policy configuration requires only the definition of the leaf/port and VLAN, entering a MAC address is optional. If the MAC field is left empty, ACI generates dynamically one MAC address that is used to rewrite the destination MAC address when sending to the L4-L7 device on the service bridge domain. These MAC addresses are not the L4-L7 device MAC addresses. They are virtual MAC addresses that ACI uses to rewrite the destination MAC address of the traffic.
If the L4-L7 device is deployed in Layer 2 mode, it must be configured statically to forward the MAC addresses that PBR uses to forward traffic to the L4-L7 device. One MAC address identifies the consumer-to-provider destination MAC address used on the service bridge domains and the other MAC address defines the provider-to-consumer destination MAC address used on the service bridge domains. These MAC addresses can be entered manually by the user in APIC as part of the redirect policy definition, or they are auto-generated if the field is left empty. The admin has to enter these MAC addresses in the configuration of the L4-L7 device in the MAC address table and be associated with the provider-side port for the MAC address used in the consumer-to-provider direction and with the consumer-side port for the provider-to-consumer direction.
Layer 1/ Layer 2 PBR is based on forwarding to a leaf/port/VLAN, hence it can only be deployed with physical domains not with VMM domains. If you need to deploy Layer 1/ Layer 2 PBR with a virtual appliance, that must be configured with a physical domain.
From a high availability perspective, the L4-L7 device is deployed in Active/Standby mode and ACI has to perform tracking in order to verify which path (leaf/port) is active and which one is standby. With Layer 1/ Layer 2 PBR, the admin has to configure tracking as part of the HA configuration.
Layer 1 and Layer 2 devices use L2 ping for link layer tracking as the L4-L7 device does not respond to TCP or ICMP ping. IP SLA type should be l2ping.

Guidelines and Limitations for Layer 1/ Layer 2 Policy-Based Redirect

Observe the following guidelines and limitations when planning Layer 1/ Layer 2 Policy-Based Redirect service nodes:

Layer 1 / Layer 2 Policy-Based Redirect is not supported from CLI.
Active-active deployment/ECMP paths are not supported for Layer 1/ Layer 2 PBR devices.
The two legs of the Layer 1 service device need to be configured on a different leaf switch to avoid packet loops. Per port VLAN is not supported.
Shared bridge domain is not supported. A Layer 1/ Layer 2 device bridge domain cannot be shared with Layer 3 device or regular EPGs.
Service node in managed mode is not supported.
Layer 1/ Layer 2 devices support physical domain only, VMM domain is not supported.
As active-active is not supported, threshold is not applicable. Down action is deny when tracking is enabled. Down action permit can not be set.
Tracking is mandatory when service devices are in Active/Standby HA mode.
For both Layer 1 and Layer 2 PBR , MAC is an optional parameter. APIC assigns the MAC address if it is not configured. In both cases, traffic is routed to the device using the MAC address which can be user configured or implicitly assigned by APIC.

Configuring Layer 1/ Layer 2 PBR Using the APIC GUI

Before you begin

Create a L4-L7 device and service graph using the Layer 1/ Layer 2 function type, see configuration steps in Configuring Policy-Based Redirect Using the GUI.

Procedure

Step 1

On the menu bar, choose Tenants > All Tenants.

Step 2

In the Navigation pane, choose Tenant tenant_name > Policies > Protocol > L4-L7 Policy Based Redirect.

Step 3

In the Work pane, choose Action > Create L4-L7 Policy Based Redirect.

Step 4

In the Create L4-L7 Policy Based Redirect dialog box, complete the following fields:

In the Name field, provide a name.
In the Destination Type field, select L1 or L2.
Expand the L1/L2 Destinations table and complete the required fields to create the redirected destination.

Click OK.

Note

Do not enter an actual interface MAC address of ASA. Either leave it blank so the APIC generates MAC automatically or enter a dummy MAC address for external policy MAC A and internal PBR policy MAC B. Remember these MAC addresses are used in ASA configuration.

Step 5

Click Submit.

Step 6

In the Navigation pane, choose Services > L4-L7 > Device Selection Policies > Logical Device Context_name.

Step 7

Expand the Logical Device and apply the Layer 1/ Layer 2 PBR policy in the L4-L7 Policy-Based Redirect field for the consumer or provider.

Step 8

Click Submit.

Configuring ASA Requirements for Layer 1/ Layer 2 PBR Using CLI

Procedure

Step 1

The ASA interfaces (service legs) need to be configured in the same bridge-group.

Example:

interface GigabitEthernet0/0
nameif externalIf
brdige-group 1

interface GigabitEthernet0/1
nameif internalIf
bridge-group 1

The ASA does not have a flood behavior. It drops any packet with an unknown destination MAC address that it has not learned. The traffic and L2 ping packet does not use the service EP MAC address as the source MAC. It is always used as destination MAC. The ASA learns from the source MAC. MAC learning is disabled to avoid conflicting entries getting created on the ASA as L2 ping uses the same source MAC to track external and internal.

Note

Apart from the configuration inside the ASA, if the ASA is running as a VM in vcenter, the vswitch requires to be configured in promiscuous mode to allow L2 ping. For Layer 2, port-groups in vswitch need to be in different VLANs, while for Layer 1, they need to be in same VLAN.

Step 2

In the following example, externalIf is the interface name on ASA, which is used as a consumer connector of the Layer 1 / Layer 2 service node. internalIf is the interface name on ASA, which is used as a provider connector of the Layer 1 / Layer 2 service node. Disable MAC learning on externalIf and internalIf. L2 ping uses the same source MAC when it tries to track both the external and internal legs.

Example:

mac-learn externalIf disable
mac-learn internalIf disable

Step 3

Configure ASA rules to permit L2 ping custom ethertype.

Example:

access-list Permit-Eth ethertype permit any
access-group Permit-Eth in interface externalIf
access-group Permit-Eth in interface internalIf

Step 4

Static MAC address table entries need to be added for L2 ping and PBR traffic to be forwarded to the appropriate interface. For example, if the service EP for consumer to provider traffic redirection has MAC A and the service EP for provider to consumer traffic redirection has MAC B:

Example:

mac-address-table static externalIf (MAC B)
mac-address-table static internalIf (MAC A)

Verifying Layer 1/ Layer 2 PBR Policy On The Leafs Using CLI

The example commands in this procedure are for configuring Layer 1 and Layer 2 Policy-Based Redirect nodes.

Procedure

Step 1	Check whether PBR group and destination information are configured on the switch: Example: sdk74-leaf4# show service redir info GrpID Name destination operSt ===== ==== =========== ====== 1 destgrp-1 dest-[50.50.50.1]-[vxlan-2719744]] enabled 2 destgrp-2 dest-[20.20.20.1]-[vxlan-2719744]] enabled Name bdVnid ip vMac vrf vrfEncap operSt ==== ====== == ==== === = dest-[20.20.20.1]-[vxlan-2719744] vxlan-16514958 20.20.20.1 00:00:14:00:00:01 coke1:cokectx1 vxlan-2719744 enabled dest-[50.50.50.1]-[vxlan-2719744] vxlan-16711542 50.50.50.1 00:00:3C:00:00:01 coke1:cokectx1 vxlan-2719744 enabled
Step 2	Check whether zoning-rule is configured with correct action and group information: Example: `sdk74-leaf4# show zoning-rule \| grep redir 4103 49155 49154 18 enabled 2719744 redir(destgrp-2) fully_qual(6) 4106 49154 49155 17 enabled 2719744 redir(destgrp-1) fully_qual(6)`
Step 3	Aclqos subcommand for PBR: Example: module-1# sh system internal aclqos services redir ? <CR> dest Dest related info group Group related info module-1# sh system internal aclqos services redir group 1 Flag Legend : 0x1: In SDK 0x10: In local DB 0x20: Delete pending 0x40: Dummy adj ***** Service key redir-group(1) *** Service flags: 0x11 Num of reference: 0x1 Num of path: 1 path 0 key: redir-dest-ipv4(vrf vnid vxlan-2719744 prefix-50.50.50.1) module-1# sh system internal aclqos services redir dest 2719744 50.50.50.1 Flag Legend : 0x1: In SDK 0x10: In local DB 0x20: Delete pending 0x40: Dummy adj *** Service key redir-dest-ipv4(vrf vnid vxlan-2719744 prefix-50.50.50.1) ***** Service flags: 0x10 Num of reference: 0x1 Num of path: 1 Ifindx: 0x18010007 Bd_vnid: 16711542 Vmac: 00:00:3c:00:00:01
Step 4	Zoning-rule command: Example: `module-1# sh system internal aclqos zoning-rules 4106 ASIC type is Sug ============================================================= Rule ID: 4106 Scope 3 Src EPG: 49154 Dst EPG: 49155 Filter 17 Redir group: 1 Curr TCAM resource: ============================= unit_id: 0 === Region priority: 1539 (rule prio: 6 entry: 3)=== sw_index = 44 \| hw_index = 44 === SDK Info === Result/Stats Idx: 81876 30 Tcam Total Entries: 1 HW Stats: 0`

Configuring Layer 1/ Layer 2 PBR Using the REST API

Procedure

Layer 1/ Layer 2 Policy-Based Redirect configuration:

Example:

<polUni>
    <fvTenant name="coke" >

        <!—For L2 device -- >
        <vnsLDevVip name="N1"  funcType="L2" managed="no">
        </vnsLDevVip>

        <!—For L1 device -- >
        <vnsLDevVip name="N1"  funcType="L1" managed="no">
        </vnsLDevVip>

        <vnsAbsGraph descr="" dn="uni/tn-coke/AbsGraph-WebGraph" name="WebGraph" ownerKey="" ownerTag="" uiTemplateType="UNSPECIFIED">

        <!—For L2 device -- >
        <vnsAbsNode descr="" funcTemplateType="OTHER" funcType="L2" isCopy="no" managed="no" name="N1" ownerKey="" ownerTag="" routingMode="Redirect" sequenceNumber="0" shareEncap="no">
    </vnsAbsNode>

       <!—For L1 device -- >
      <vnsAbsNode descr="" funcTemplateType="OTHER" funcType="L1" isCopy="no" managed="no" name="N1" ownerKey="" ownerTag="" routingMode="Redirect" sequenceNumber="0" shareEncap="no">
    </vnsAbsNode>

    </vnsAbsGraph>

    <fvIPSLAMonitoringPol name="Pol2" slaType="l2ping"/>
<vnsSvcCont>
<vnsRedirectHealthGroup name="2" />
             <vnsSvcRedirectPol name="N1Ext"  destType="L2">
                   <vnsRsIPSLAMonitoringPol tDn="uni/tn-coke/ipslaMonitoringPol-Pol2"/>      
     <vnsL1L2RedirectDest destName="1">
             	 	<vnsRsL1L2RedirectHealthGroup tDn="uni/tn-coke/svcCont/redirectHealthGroup-2"/>
		         	<vnsRsToCIf tDn="uni/tn-coke/lDevVip-N1/cDev-ASA1/cIf-[Gig0/0]"/>
		</vnsL1L2RedirectDest>
             </vnsSvcRedirectPol>

             <vnsSvcRedirectPol name="N1Int" destType="L2">
                   <vnsRsIPSLAMonitoringPol tDn="uni/tn-coke/ipslaMonitoringPol-Pol2"/>       
      <vnsL1L2RedirectDest destName="2">
             	 	<vnsRsL1L2RedirectHealthGroup tDn="uni/tn-coke/svcCont/redirectHealthGroup-2"/>
	         	<vnsRsToCIf tDn="uni/tn-coke/lDevVip-N1/cDev-ASA1/cIf-[Gig0/1]"/>
  	 	</vnsL1L2RedirectDest>
          </vnsSvcRedirectPol>
        </vnsSvcCont>
</fvTenant>
</polUni>

Policy Based Redirect and Tracking Service Nodes

Note

This feature is available in the APIC Release 2.2(3x) release and going forward with APIC Release 3.1(1). It is not supported in APIC Release 3.0(x).

With Cisco APIC, Release 2.2(3x), Policy Based Redirect feature (PBR) supports tracking service nodes:

Redirect Destination nodes support dual IP stack. Therefore, both IPv4 and IPv6 addresses can be configured at the same time.

Switches internally use the Cisco IP SLA monitoring feature to support the PBR tracking. The tracking feature marks a Redirect Destination node down if the service node is not reachable. The tracking feature marks a Redirect Destination node up if the service node resumes connectivity. When a service node is marked down, it will not be used to send or hash the traffic. Instead, the traffic will be sent or hashed to a different service node in the cluster of Redirection Destination nodes.

To avoid black holing of the traffic in one direction, you can associate a service node’s ingress and egress Redirect Destination nodes with a Redirection Health Policy. Doing so ensures that if either an ingress or egress Redirection Destination node is down, the other Redirection Destination node will also be marked down. Hence, both ingress and egress traffic gets hashed to a different service node in the cluster of the Redirect Destination nodes.

Threshold Settings

The following threshold settings are available when configuring the PBR policy for tracking service nodes:

Threshold enabled or disabled: When the threshold is enabled, you an specify the minimum and maximum threshold percentages. Threshold enabled is required when you want to disable the redirect destination group completely and prevent any redirection. When there is no redirection, the traffic is directly sent between the consumer and the provider.
Minimum threshold: The minimum threshold percentage specified. If the traffic goes below the minimum percentage, the packet is permitted instead of being redirected. The default value is 0.
Maximum threshold: The maximum threshold percentage specified. Once the minimum threshold is reached, to get back to operational state, the maximum percentage must first be reached. The default value is 0.

Let us assume as an example that there are three redirect destinations in a policy. The minimum threshold is specified at 70% and the maximum threshold is specified at 80%. If one of the three redirect destination policies goes down, the percentage of availability goes down by one of three so 33% which is less than the minimum threshold. As a result, the minimum threshold percentage of the redirect destination group is brought down and traffic begins to get permitted instead of being redirected. Continuing with the same example, if the maximum threshold is 80%, to bring the redirect policy destination group back to an operational state, a percentage greater than the maximum threshold percentage must be reached first.

Guidelines and Limitations for Policy Based Redirect and Tracking Service Nodes

Follow these guidelines and limitations when utilizing PBR tracking and service nodes:

Destination groups that share destinations must have same health group and IP SLA monitoring policies configured.
Starting in release 4.0(1), remote leaf configurations support PBR tracking, but only if system-level Global GIPo is enabled. See Configuring Global GIPo for Remote Leaf Using the GUI.
Starting in release 4.0(1), remote leaf configurations support PBR resilient hashing.
Multipod fabric setup is supported. Multi-site setup is not supported.
Layer 3 Out is supported for consumer and provider EPGs.
TCP or ICMP protocol types are used to track the Redirect Destination nodes.
Maximum number of trackable IP addresses supported by Policy Based Redirect is 100 in leaf switches and 200 in the ACI fabric.
Maximum number graph instances in the ACI fabric is 1000 per fabric.
Maximum number of graph instances per device is 100.
Maximum number of service nodes that can be configured for PBR is 40 per policy.
Maximum number of service nodes supported in one Service Chain is three.
Shared services are supported with PBR tracking.
The following threshold down actions are supported:
- bypass action
- deny action
- permit action

Configuring PBR and Tracking Service Nodes Using the GUI

Procedure

Step 1

On the menu bar, click Tenant > tenant_name . In the navigation pane, click Policies > Protocol > L4-L7 Policy Based Redirect .

Step 2

Right-click L4 –L7 Policy Based Redirect, and click Create L4–L7 Policy Based Redirect.

Step 3

In the Create L4–L7 Policy Based Redirect dialog box, perform the following actions:

In the Name field, enter a name for the PBR policy.

In the dialog box, choose the appropriate settings to configure the hashing algorithm, IP SLA Monitoring Policy, and other required values.

Note

Destination groups that share destinations must have same IP SLA monitoring policy configured.

In the threshold setting fields, specify the settings as appropriate and if desired.
Expand Destinations to display Create Destination of Redirected Traffic.

In the Create Destination of Redirected Traffic dialog box, enter the appropriate details including the IP address and the MAC address fields.

The fields for IP address and Second IP address are provided where you can specify IPv4 and/or IPv6 addresses.

Note

This field is not mandatory. Use it if the L4-L7 device has multiple IP addresses and you want ACI to verify both of them.

If both the IP and Second IP parameters are configured, both must be up in order to mark the PBR destination as "UP".

In the Redirect Health Group field, associate an existing health group or create a new health group, as appropriate. Click OK.

Note

Destination groups that share destinations must have same health group configured.

In the Create L4–L7 Policy Based Redirect dialog box, click Submit.

The L4-L7 Policy Based Redirect and tracking of service nodes is configured after binding the redirect health group policy to the L4-L7 PBR policy and the settings to track the redirect destination group are enabled.

Configuring a Redirect Health Group Using the GUI

Procedure

Step 1

On the menu bar, click Tenant > tenant_name. In the navigation pane, click Policies > Protocol > L4-L7 Redirect Health Groups.

Step 2

Right-click L4 –L7 Redirect Health Groups, and click Create L4–L7 Redirect Health Group.

Step 3

In the Create L4–L7 Redirect Health Group dialog box, perform the following actions:

In the Name field, enter a name for the Redirect Health Group policy.
In the Description field, enter additional information if appropriate, and click Submit.

The L4-L7 Redirect Health Policy is configured.

Configuring IP SLA Monitoring Policy Using the GUI

To enable Cisco APIC to send monitoring probes for a specific SLA type using the APIC GUI, perform the following steps:

Procedure

Step 1

On the menu bar, click Tenant > tenant_name. In the navigation pane, click Policies > Protocol > IP SLA.

Step 2

Right-click IP SLA Monitoring Policies, and click Create IP SLA Monitoring Policy.

Step 3

In the Create IP SLA Monitoring Policy dialog box, perform the following actions:

In the Name field, enter a unique name for the IP SLA Monitoring policy.

In the SLA Frequency field, enter the interval probe time in seconds. The minimum interval time is 1 second.

Note

The failure detection time is three times the probe interval.

In the SLA Type field, choose the SLA type. Click Submit.

The SLA type can be TCP or ICMP. ICMP is the default value.

Note

L2Ping is supported only for L1/L2 PBR tracking.

If you chose TCP, enter a port number in the Destination Port field.

The IP SLA Monitoring Policy is configured.

Configuring Global GIPo for Remote Leaf Using the GUI

Performing this task allows PBR tracking to function in remote leaf configurations.

Note

This configuration must be performed for PBR tracking to function on a remote leaf. Without this configuration, PBR tracking will not work on the remote leaf, even when the main data center is reachable.

Procedure

Step 1	On the menu bar, click System > System Settings.
Step 2	In the System Settings navigation pane, click System Global GIPo.
Step 3	In the System Global GIPo Policy work pane, click Enabled.
Step 4	In the Policy Usage Warning dialog, review the nodes and policies that may be using the GIPo policy and, if appropriate, click Submit Changes.

Configuring PBR to Support Tracking Service Nodes Using the REST API

Procedure

Configure PBR to support tracking service nodes.

Example:


<polUni>
    <fvTenant name="coke" >
    <fvIPSLAMonitoringPol name="tcp_Freq60_Pol1" slaType="tcp" slaFrequency="60" slaPort="2222" />
    <vnsSvcCont>
        <vnsRedirectHealthGroup name="fwService1"/>
          <vnsSvcRedirectPol name="fwExt" hashingAlgorithm="sip" thresholdEnable="yes" minThresholdPercent="20" maxThresholdPercent="80">
            <vnsRedirectDest ip="40.40.40.100" mac="00:00:00:00:00:01">
               <vnsRsRedirectHealthGroup tDn="uni/tn-coke/svcCont/redirectHealthGroup-fwService1"/>
            </vnsRedirectDest>
            <vnsRsIPSLAMonitoringPol tDn="uni/tn-coke/ipslaMonitoringPol-tcp_Freq60_Pol1"/>
          </vnsSvcRedirectPol>
         <vnsSvcRedirectPol name="fwInt" hashingAlgorithm="sip" thresholdEnable="yes" minThresholdPercent="20" maxThresholdPercent="80">
             <vnsRedirectDest ip="30.30.30.100" mac="00:00:00:00:00:02">
                <vnsRsRedirectHealthGroup tDn="uni/tn-coke/svcCont/redirectHealthGroup-fwService1"/>
             </vnsRedirectDest>
             <vnsRsIPSLAMonitoringPol tDn="uni/tn-coke/ipslaMonitoringPol-tcp_Freq60_Pol1"/>
          </vnsSvcRedirectPol>
        </vnsSvcCont>
    </fvTenant>
</polUni>

About Location-Aware Policy Based Redirect

Location-Aware Policy Based Redirect (PBR) is now supported. This feature is useful in a multipod configuration scenario. Now there is pod-awareness support, and you can specify the preferred local PBR node. When you enable location-aware redirection, and Pod IDs are specified, all the redirect destinations in the Layer 4-Layer 7 PBR policy will have pod awareness. The redirect destination is programmed only in the leaf switches located in a specific pod.

The following image displays an example with two pods. PBR nodes A and B are in Pod 1 and PBR nodes C and D are in Pod 2. When you enable the location-aware PBR configuration, the leaf switches in Pod 1 prefer to use PBR nodes A and B, and the leaf switches in Pod 2 use PBR nodes in C and D. If PBR nodes A and B in Pod 1 are down, then the leaf switches in Pod 1 will start to use PBR nodes C and D. Similarly, if PBR nodes C and D in Pod 2 are down, the leaf switches in Pod 2 will start to use PBR nodes A and B.

Figure 10. An Example of Location Aware PBR Configuration with Two Pods

Guidelines for Location-Aware PBR

Follow these guidelines when utilizing location-aware PBR:

The Cisco Nexus 9300 (except Cisco Nexus 9300–EX and 9300–FX) platform switches do not support the location-aware PBR feature.
Use location-aware PBR for north-south firewall integration with GOLF host advertisement.

Configuring Location-Aware PBR Using the GUI

You must program two items for this feature to be enabled. Enable pod ID aware redirection and associate the Pod IDs with the preferred PBR nodes to program redirect destinations in the leaf switches located in the specific pods.

Procedure

Step 1

On the menu bar, click Tenant > tenant_name . In the Navigation pane, click Policies > Protocol > L4-L7 Policy Based Redirect .

Step 2

Right-click L4 –L7 Policy Based Redirect, and click Create L4–L7 Policy Based Redirect.

Step 3

In the Create L4–L7 Policy Based Redirect dialog box, perform the following actions:

In the Name field, enter a name for the PBR policy.
In the Enable Pod ID Aware Redirection check the check box.
In the dialog box, choose the appropriate settings to configure the hashing algorithm, IP SLA Monitoring Policy, and other required values.
In the threshold setting fields, specify the settings as appropriate and if desired.
Expand Destinations to display Create Destination of Redirected Traffic.
In the Create Destination of Redirected Traffic dialog box, enter the appropriate details including the IP address and the MAC address fields.

The fields for IP address and Second IP address are provided where you can specify an IPv4 address and an IPv6 address.
In the Pod ID field, enter the pod identification value.
In the Redirect Health Group field, associate an existing health group or create a new health group, as appropriate. Click OK.

Create additional destinations of redirected traffic with different Pod IDs as required.
In the Create L4–L7 Policy Based Redirect dialog box, click Submit.

The L4-L7 location-aware PBR is configured.

Configuring Location-Aware PBR Using the REST API

You must configure two items to enable location-aware PBR and to program redirect destinations in the leaf switches located in the specific pods. The attributes that are configured to enable location-aware PBR in the following example are: programLocalPodOnly and podId.

Procedure

Configure location-aware PBR.

Example:


<polUni>
    <fvTenant name="coke" >
    <fvIPSLAMonitoringPol name="icmp_Freq60_Pol1" slaType="icmp" slaFrequency="60"/>
    <vnsSvcCont>
        <vnsRedirectHealthGroup name="fwService1"/>
          <vnsSvcRedirectPol name="fwExt" hashingAlgorithm="sip" thresholdEnable="yes" minThresholdPercent="20" maxThresholdPercent="80" programLocalPodOnly="yes">
            <vnsRedirectDest ip="40.40.40.100" mac="00:00:00:00:00:01" podId="2">
               <vnsRsRedirectHealthGroup tDn="uni/tn-coke/svcCont/redirectHealthGroup-fwService1"/>
            </vnsRedirectDest>
            <vnsRsIPSLAMonitoringPol tDn="uni/tn-coke/ipslaMonitoringPol-icmp_Freq60_Pol1"/>
          </vnsSvcRedirectPol>
          <vnsSvcRedirectPol name="fwInt" hashingAlgorithm="dip" thresholdEnable="yes" minThresholdPercent="20" maxThresholdPercent="80">
             <vnsRedirectDest ip="30.30.30.100" mac="00:00:00:00:00:02">
                <vnsRsRedirectHealthGroup tDn="uni/tn-coke/svcCont/redirectHealthGroup-fwService1"/>
             </vnsRedirectDest>
             <vnsRsIPSLAMonitoringPol tDn="uni/tn-coke/ipslaMonitoringPol-icmp_Freq60_Pol1"/>
          </vnsSvcRedirectPol>
        </vnsSvcCont>
    </fvTenant>
</polUni>

Policy-Based Redirect and Service Graphs to Redirect All EPG-to-EPG Traffic Within the Same VRF Instance

You can configure Cisco Application Centric Infrastructure (Cisco ACI) to forward all traffic from any endpoint group to any other endpoint group in the same VRF instance through a Layer 4 to Layer 7 device by configuring vzAny with service graph redirect. vzAny is a construct that represents all the endpoint groups under the same VRF instance. vzAny is sometimes referred to as "any EPG."

Traffic between any endpoint group pair that is under the same VRF instance can be redirected to a Layer 4 to Layer 7 device, such as a firewall. You can also redirect traffic within the same bridge domain to a firewall. The firewall can filter traffic between any pair of endpoint groups, as illustrated in the following figure:

Figure 12. A firewall filtering traffic between any pair of EPGs

One use case of this functionality is to use Cisco ACI as a default gateway, but filter traffic through a firewall. With vzAny and a policy-based redirect policy, the security administrator manages the ACL rules and the network administrator manages routing and switching. Some of the benefits of this configuration include being able to use the Cisco Application Policy Infrastructure Controller's (Cisco APIC's) tools, such as endpoint tracking, first hop security with ARP inspection, or IP address source guard.

Applying a service graph with a policy-based redirect policy also enables the following functionality:

Firewall clustering
Firewall health tracking
Location-aware redirection

Prior to the Cisco APIC 3.2 release, you could use vzAny as the consumer of a contract. Starting in the Cisco APIC 3.2 release, you can also use vzAny as the provider of a contract. This enhancement enables the following configurations:

vzAny as the provider and vzAny as the consumer (policy-based redirect with one-arm only)
vzAny as the provider and a regular endpoint group as the consumer (policy-based redirect and non-policy-based redirect case)

After you have applied a service graph with a policy-based redirect policy that redirects traffic using vzAny, if you want some traffic to bypass the firewall, such as for data backup traffic between two servers, you can create a more specific contract between the endpoint groups. For example, two endpoint groups can transmit traffic to one another directly over a given port. More specific rules win over the "any EPG to any EPG" redirect rule.

Guidelines and Limitations for Configuring a Policy-Based Redirect Policy with a Service Graph to Redirect All EPG-to-EPG Traffic Within the Same VRF Instance

The following guidelines and limitations apply when configuring a policy-based redirect policy with a service graph to redirect all EPG-to-EPG traffic within the same VRF instance:

The Layer 4 to Layer 7 device and vzAny must belong to the same VRF instance.
You must deploy the Layer 4 to Layer 7 device in one-arm mode.
vzAny configured with a multinode service graph might work, but this configuration has not been tested and is unsupported; use at your own risk.
You can only deploy the Layer 4 to Layer 7 device in unmanaged mode.
The use in conjunction with VRF leaking is not implemented. You cannot have vzAny of a VRF instance providing or consuming a vzAny contract of another VRF instance.
You can have a contract between endpoint groups and vzAny in different tenants as long as they belong to the same VRF instance, such as if the VRF instance is in tenant Common.
In a multipod environment, you can use vzAny as a provider and consumer.
In a Cisco ACI Multi-Site environment, you cannot use vzAny as a provider and consumer across sites.

Configuring a Policy-Based Redirect Policy with a Service Graph to Redirect All EPG-to-EPG Traffic Within the Same VRF Instance

The following procedure configures a policy-based redirect policy with service graphs to redirect all EPG-to-EPG traffic within the same VRF instance:

Procedure

Step 1	Create the service bridge domain that you will dedicate to the connectivity of the Layer 4 to Layer 7 device. For information about creating a bridge domain, see the Cisco APIC Basic Configuration Guide. On the STEP 1 > Main screen: In the VRF drop-down list, choose the VRF instance that contains the endpoint groups. In the Forwarding drop-down list, if you choose Custom, then in the L2 Unknown Unicast drop-down list, you can choose Flood if desired. On the STEP 2 > L3 Configurations screen: Ensure that there is a check in the Unicast Routing check box. In the Subnets table, create a subnet. The Gateway IP address must be in the same subnet as the IP address that you will give to the Layer 4 to Layer 7 device interface. Remove the check from the Endpoint Dataplane Learning check box.
Step 2	Create the redirect policy. In the Navigation pane, choose Tenant tenant_name > Networking > Policies > Protocol > L4-L7 Policy Based Redirect. Right-click L4-L7 Policy Based Redirect and choose Create L4-L7 Policy Based Redirect. In the Name field, enter a name for the policy. In the Destinations table, click +. In the Create Destination of Redirected Traffic dialog, enter the following information: IP—Enter the IP address that you will assign to the Layer 4 to Layer 7 device. The IP address must be in the same subnet as the IP address that you have given to the bridge domain. MAC—Enter the MAC address that you will assign to the Layer 4 to Layer 7 device. You should use a MAC address that is valid also upon failover of the Layer 4 to Layer 7 device. For example, in the case of a ASA firewall, this is called a "virtual MAC." Enter any other desired values, then click OK. In the Create L4-L7 Policy Based Redirect dialog, enter any other desired values, then click Submit.
Step 3	Create the Layer 4 to Layer 7 device with one concrete interface and one logical interface. For information about creating a Layer 4 to Layer 7 device, see Creating a Layer 4 to Layer 7 Device Using the GUI.
Step 4	Create the service graph template with route redirect enabled. In the Navigation pane, choose Tenant tenant_name > Services > L4-L7 > Service Graph Template. Right-click Service Graph Template and choose Create Service Graph Template. In the Name field, enter a name for the service graph. If you did not previously create the Layer 4 to Layer 7 device, in the Device Clusters pane, create the device. Drag and drop the Layer 4 to Layer 7 device from the Device Clusters pane to in-between the consumer EPG and provider EPG. For the L4L7 radio buttons, click Routed. Put a check in the Routed Redirect check box. Click Submit.
Step 5	Apply the service graph to the vzAny (AnyEPG) endpoint group. On the STEP 1 > Contract screen: In the Navigation pane, choose Tenant tenant_name > Services > L4-L7 > Service Graph Template > `service_graph_name` . `service_graph_name` is the service graph template that you just created. Right-click the service graph template and choose Apply L4-L7 Service Graph Template. In the Consumer EPG / External Network drop-down list, choose the AnyEPG list item that corresponds to the tenant and VRF instance that you want to use for this use case. For example, if the tenant is "tenant1" and the VRF instance is "vrf1," choose tenant1/vrf1/AnyEPG. In the Provider EPG / Internal Network drop-down list, choose the same AnyEPG list item that you chose for the consumer EPG. In the Contract Name field, enter a name for the contract. Click Next. On the STEP 2 > Graph screen: For both BD drop-down lists, choose the Layer 4 to Layer 7 service bridge domain that you created in step 1. For both Redirect Policy drop-down lists, choose the redirect policy that you created for this use case. For the Consumer Connector Cluster Interface drop-down list, choose the cluster interface (logical interface) that you created in step 3. For the Provider Connector Cluster Interface drop-down list, choose the same cluster interface (logical interface) that you created in step 3. Click Finish.

Results

Chapter: Configuring Policy-Based Redirect

Configuring Policy-Based Redirect

About Policy-Based Redirect

About Multi-Node Policy-Based Redirect

About Symmetric Policy-Based Redirect

Policy Based Redirect and Hashing Algorithms

Policy-Based Redirect Resilient Hashing

Enabling Resilient Hashing in L4-L7 Policy-Based Redirect

Before you begin

Procedure

About Bypass Action

deny action

permit action

bypass action

Guidelines and Limitations

Configuring the Threshold Down Action in Layer 4 to Layer 7 Policy-Based Redirect

Before you begin

Procedure

About Policy-Based Redirect with L3Out

Configuring Policy-Based Redirect with L3Out

Example Use Case for Policy-Based Redirect with L3Out

Guidelines and Limitations

PBR Support for Service Nodes in Consumer and Provider Bridge Domains

Guidelines and Limitations for Configuring Policy-Based Redirect

Configuring Policy-Based Redirect Using the GUI

Procedure

Configuring Policy-Based Redirect Using the NX-OS-Style CLI

Procedure

Example:

Example:

Example:

Example:

Example:

Example:

Example:

Example:

Example:

Example:

Verifying a Policy-Based Redirect Configuration Using the NX-OS-Style CLI

Procedure

Example:

Example:

Example:

About Layer 1/ Layer 2 Policy-Based Redirect

Guidelines and Limitations for Layer 1/ Layer 2 Policy-Based Redirect

Configuring Layer 1/ Layer 2 PBR Using the APIC GUI

Before you begin

Procedure

Configuring ASA Requirements for Layer 1/ Layer 2 PBR Using CLI

Procedure

Example:

Example:

Example:

Example:

Verifying Layer 1/ Layer 2 PBR Policy On The Leafs Using CLI

Procedure

Example:

Example:

Example:

Example:

Configuring Layer 1/ Layer 2 PBR Using the REST API

Procedure

Example:

Policy Based Redirect and Tracking Service Nodes

Threshold Settings

Guidelines and Limitations for Policy Based Redirect and Tracking Service Nodes

Configuring PBR and Tracking Service Nodes Using the GUI

Procedure

Configuring a Redirect Health Group Using the GUI

Procedure

Configuring IP SLA Monitoring Policy Using the GUI

Procedure

Configuring Global GIPo for Remote Leaf Using the GUI

Procedure

Configuring PBR to Support Tracking Service Nodes Using the REST API

Procedure

Example:

About Location-Aware Policy Based Redirect