Distributed Firewall

This chapter contains the following sections:

About Distributed Firewall

The Distributed Firewall is a hardware-assisted firewall. It supplements—but does not replace—other security features in the Cisco Application Centric Infrastructure (ACI) fabric such as Cisco Adaptive Security Virtual Appliance (ASAv) or secure zones created by Microsegmentation with Cisco ACI Virtual Edge.

No additional software is required for the Distributed Firewall to work. However, you must configure policies in the Cisco Application Policy Infrastructure Controller (APIC) to work with the Distributed Firewall.

The Distributed Firewall is supported on all Virtual Ethernet (vEth) ports but is disabled for kni-opflex, kni-ave-ctrl dpdk interfaces and for all uplink ports.

Key Features of the Distributed Firewall

Feature

Description

Provides dynamic packet filtering (also known as stateful inspection)

Tracks the state of TCP and FTP connections and blocks packets unless they match a known active connection. Traffic from the Internet and internal network is filtered based on policies that you configure in the APIC GUI.

Is distributed

Tracks connections even if you use vMotion to move virtual machines (VMs) to other servers.

Prevents SYN-ACK attacks

When the provider VM initiates SYN-ACK packets, the Distributed Firewall on the provider Cisco ACI Virtual Edge drops these packets because no corresponding flow (connection) is created.

Supports TCP flow aging

Connections in ESTABLISHED state are maintained for 2 hours unless the per-port limit reaches the 75% threshold. Once that threshold is reached, any new connection can potentially replace the old connection (which has been inactive for at least 5 minutes).

Connections in non-ESTABLISHED TCP state are retained for 5 minutes of idle or inactive time.

Is implemented at the flow level

Enables a flow between VMs over the TCP connection, eliminating the need to establish a TCP/IP connection for each packet.

Not dependent on any particular topology or configuration

Works with either Local Switching and No Local Switching modes and with either VLAN and VXLAN.

Is hardware-assisted

In the ACI fabric, Cisco Nexus 9000 leaf switches store the policies, avoiding impact on performance.

Bases implementation on 5-tuple values

Uses the source and destination IP addresses, the source and destination ports, and the protocol in implementing policies.

Is in learning mode by default

Facilitates upgrades. Distributed Firewall must be in learning mode if you migrate to Cisco ACI Virtual Edge from Cisco AVS if the version of Cisco AVS is earlier than Release 5.2(1)SV3(1.5). Those versions do not support Distributed Firewall.

Benefits of Distributed Firewall

This section provides examples of how Distributed Firewall works with hardware in the Cisco ACI fabric to provide security.

Enhanced Security for Reflexive ACLs

An administrator creates a contract using subjects and filters in the Cisco APIC between consumer and provider EPGs to allow web traffic. The administrator creates a policy in Cisco APIC to allow traffic from any source port to destination port 80.

When the policy is configured in Cisco APIC, a reflexive access control list (ACL) entry from the provider to the consumer is automatically programmed in the ACI hardware. This reflexive ACL is created to allow the reverse traffic for the time when a connection remains established. This reflexive ACL entry is necessary to allow the reverse traffic to flow.

Because of the automatic reflexive ACL creation, the leaf switch allows the provider to connect to any client port when the connection is in the established state. But this may not be desirable for some data centers. That is because an endpoint in a provider EPG may initiate a SYN attack or a port-scan to the endpoints in the consumer EPGs using its source port 80.

However, the Distributed Firewall, with the help of the physical hardware, will not allow such attack. The physical leaf hardware evaluates the packet it receives from the hypervisor against the policy ternary content addressable memory (TCAM) entry.

Protecting Data When VMs Are Moved with VMotion

Every packet sent or received follows the flow-based entry in the Distributed Firewall in the Cisco ACI Virtual Edge and in the physical leaf. Since the flows are directly attached to a virtual machine (VM) virtual Ethernet (vEth) interface, even when VMs are moved by VMotion to a different hypervisor host, the flows and table entries move with it to the new hypervisor.

This movement is also reported back to physical leaf. The physical leaf allows the legitimate flow to continue and prevents attacks if they occur. So even when the VM is moved to the new hosts, VM is still communicating without losing protection.

Seamless FTP Traffic Handling

The behavior and inter-working of the FTP protocol is different than other TCP-based protocols. For this reason, it requires special treatment in the Distributed Firewall. FTP Server (Provider) listens on the Control port (TCP port 21) and a Data port (TCP port 20). When communication begins between FTP client (Consumer) and server (Provider), the control connection is set up initially between the FTP client and server. The data connection is set up on demand (only when there is data to be exchanged) and torn down immediately after the data transfer.

Distributed Firewall supports only Active-FTP mode handling. The data connections are not tracked for the Passive-FTP mode.

Distributed Firewall allows the FTP data connection only if it matches the FTP Client IP and Port information that was received during the control connection handshake. Distributed Firewall blocks the FTP data connections if there is no corresponding control connection; this is what prevents FTP attacks.

Distributed Firewall Configuration

You configure Distributed Firewall by setting it to one of its three modes:

  • Enabled—Enforces the Distributed Firewall.

  • Disabled—Does not enforce Distributed Firewall. Use this mode only if you do not want to use the Distributed Firewall. Disabling Distributed Firewall removes all flow information on the Cisco ACI Virtual Edge.

  • Learning—Cisco ACI Virtual Edge monitors all TCP communication and creates flows in a flow table but does not enforce the firewall. Learning is the default mode.

Distributed Firewall works with policies created in Cisco APIC; unless you create the policies, Distributed Firewall cannot work effectively.


Note
We recommend that you use vmxnet3 adapters for the VMs when using Distributed Firewall.

Important
When Distributed Firewall is enabled on a Cisco ACI Virtual Edge VMM domain, there are restrictions on vMotion. See the section Guidelines for Using VMware vMotion with Cisco ACI Virtual Edge in this guide for more information.

Workflow for Distributed Firewall Configuration

This section provides a high-level description of the tasks that you perform to configure Distributed Firewall.

  1. Create an interface policy group to enable the firewall policy in the Cisco APIC, or, if you already have an interface policy group, make sure that it contains a firewall policy.

  2. Configure a stateful policy for Distributed Firewall.

    Follow instructions in the section Configure a Stateful Policy for Distributed Firewall Using the GUI in this guide.

  3. Change the Distributed Firewall mode if necessary.

    Distributed Firewall is in learning mode by default. If you have not previously enabled Distributed Firewall, follow the instructions in this guide to for changing the Distributed Firewall mode.

  4. Cisco ACI Virtual Edge reports the flows that are permitted or denied by Distributed Firewall to the system log (syslog) server. You can configure parameters for the flows and view the denied flows on the syslog server. See the instructions in the sectionDistributed Firewall Flow Logging in this guide.

  5. Choose which Distributed Firewall flow count statistics that you want to view.

    Cisco ACI Virtual Edge collects Distributed Firewall flow information, but you must choose which statistics you want to know about before you can view them. See the section Distributed Firewall Flow Counts in this guide for instructions.

Configure a Stateful Policy for Distributed Firewall Using the GUI

Before you can configure a Distributed Firewall policy, configure a stateful policy for Distributed Firewall.

Procedure

Step 1

Log in to the Cisco APIC.

Step 2

Choose Tenants > tenant.

Step 3

In the navigation pane, expand the folder for the tenant.

Step 4

Right-click the Contracts folder and then choose Create Contract.

Step 5

In the Create Contract dialog box, in the Name field, type a name for the contract.

Step 6

In the Subjects area, click the + icon.

Step 7

In the Create Contract Subject dialog box, in the Name field, type a name for the subject.

Step 8

In the Filter Chain area, click the + icon next to Filters.

Step 9

Click the down arrow to display the Name drop-down filter list, and then click the + icon at the top of the Name list.

Step 10

In the Create Filter dialog box, complete the following actions:

  1. In the Name field, type a name for the filter.

  2. In the Entries area, click the + icon to display more fields.

  3. In the Name field, type a name to further describe the filter.

  4. From the Ether Type drop-down list, choose IP.

  5. From the IP Protocol field, choose tcp.

  6. Check the Stateful check box.

  7. (Optional) In the Source Port / Range field, from the To and the From drop-down lists, choose Unspecified, the default.

  8. In the Destination Port / Range field, from the To and the From drop-down lists, choose http.

  9. Click Update and then click Submit.

Step 11

In the Create Contract Subject dialog box, in the Filters area, click Update and then click OK.

Step 12

In the Create Contract dialog box, click Submit.

What to do next

Create a Distributed Firewall policy.

Create a Distributed Firewall Policy Using the GUI

You can create a Distributed Firewall policy using the Cisco APIC GUI.

Before you begin

You must have done the following:

  • Created an interface policy group to enable the Distributed Firewall policy in Cisco APIC.

  • Created a stateful policy for Distributed Firewall.

Procedure

Step 1

Log in to the Cisco APIC.

Step 2

Go to Fabric > Access Policies.

Step 3

In the Policies navigation pane, expand the Policies and Interface folders.

Step 4

Right-click the Firewall folder and choose Create Firewall Policy.

Step 5

In the Create Firewall Policy dialog box, in the Name field, type a name for the policy.

Step 6

In the Mode area, choose a mode.

The default mode is Learning to facilitate upgrades.

Distributed Firewall must be in Learning mode if you migrate to Cisco ACI Virtual Edge from Cisco AVS if the version of Cisco AVS is earlier than Release 5.2(1)SV3(1.5). Those versions do not support Distributed Firewall.

Otherwise, enable Distributed Firewall.

Note

 
Do not change the mode from Disabled directly to Enabled. Doing so can lead to traffic loss. Instead, from Disabled mode, change the mode to Learning, wait 5 minutes, and then change the mode to Enabled. The Create Firewall Policy dialog box includes a Syslog area. This is where you can configure the source for Distributed Firewall flow information that is sent to the syslog server. See the section Distributed Firewall Flow Logging in this guide for instructions.
 

Step 7

Click Submit.

Step 8

Associate the new policy with the VMM domain by completing the following steps:

  1. Go to Virtual Networking > Inventory.

  2. In the Inventory navigation pane, expand the VMM Domains folder and the VMware folder, and then choose the relevant VMM domain.

  3. In the VMM domain work pane, click the VSwitch Policies tab.

  4. In the Properties work pane, from the Firewall Policy drop-down list, choose the firewall policy that you created.

  5. Click Submit.

What to do next

Verify that the Distributed Firewall policy is created and is in the desired state by completing the following steps:

  1. Go to Fabric > Access Policies.

  2. In the Policies navigation pane, expand the Policies, Interface , and Firewall folders.

  3. Choose the policy.

  4. In the Properties work pane, verify that the policy appears and that the mode is correct.

Change Distributed Firewall Policy Mode Using the GUI

Use the following procedure to change the Distributed Firewall mode.


Note
Enable Distributed Firewall if you migrated from Cisco AVS to Cisco ACI Virtual Edge and did not have Distributed Firewall enabled for Cisco AVS.

Before you begin

Ensure that your Distributed Firewall policy is associated with a VMM domain.

Procedure

Step 1

Log in to the Cisco APIC.

Step 2

Go to Fabric > Access Policies.

Step 3

In the Policies navigation pane, expand the Policies, Interface, and Firewall folders.

Step 4

Click the policy that you want to modify.

Step 5

In the Properties work pane, in the Mode area, choose a mode, and then click Submit.

Note

 
Do not change the mode from Disabled directly to Enabled. Doing so can lead to traffic loss. Instead, from Disabled mode, change the mode to Learning, wait 5 minutes, and then change the mode to Enabled. Changing to Learning mode allows Cisco ACI Virtual Edge to add flow table entries for existing flows.
 

Note

 
The Properties work pane includes a Syslog area where you can configure the source for Distributed Firewall flow information that is sent to the syslog server. See the section Distributed Firewall Flow Logging in this guide for instructions.

What to do next

Verify that the Distributed Firewall is in the desired state by completing the following steps:

  1. In the Policies navigation pane, choose the policy in the Firewall folder.

  2. In the Properties dialog box, verify that the mode is correct.

Distributed Firewall Flow Logging

You can view flow information for Distributed Firewall with the Cisco APIC to assist with auditing network security.

Cisco ACI Virtual Edge reports the flows that are denied and permitted by Distributed Firewall to the system log (syslog) server. When you enable Distributed Firewall, Cisco ACI Virtual Edge monitors TCP, UDP, and ICMP traffic by default. It also tracks, logs, and—depending on how you configure parameters—permits or denies TCP traffic. You can view the denied and permitted flows on the syslog server.

Parameters for Distributed Firewall Flow Information

Cisco ACI Virtual Edge reports the flows that are denied or permitted by Distributed Firewall as well UDP and ICMP flows to the system log (syslog) server.

You configure Distributed Firewall logging in two tasks: configuring up to three syslog servers, referred to as remote destinations in the GUI, and configuring the syslog policy. You can configure the following parameters:

  • Syslog server parameters

    • Enable/disable


      Note
      Distributed Firewall logging is disabled by default.

    • Permitted flows, Denied flows, or both

    • Polling interval

      You can set the interval for exporting the flows from 60 seconds to 24 hours.


      Note
      A polling interval of 125 seconds is required to send data at maximum scale. We recommend that you configure the syslog timer with a polling interval of at least 150 seconds.

    • Log severity

      You can set the severity level from 0-7.

  • Syslog policy parameters

    • IP address

    • Port

    • Log severity

      You can set the severity level from 0-7.

    • Log facility

Cisco ACI Virtual Edge reports up to 250,000 denied or permitted flows to the syslog server for each polling interval. If you choose to log denied and permitted flows, Cisco ACI Virtual Edge reports up to 500,000 flows. Cisco ACI Virtual Edge also reports up to 100,000 short-lived flows—flows that are shorter than the polling interval.

Syslog messages are sent only if the syslog destination log severity is at or below the same log severity for the syslog policy. Severity levels for the syslog server and syslog policy are as follows:

  • 0: Emergency

  • 1: Alert

  • 2: Critical

  • 3: Error

  • 4: Warning

  • 5: Notification

  • 6: Information

  • 7: Debug

Guidelines for Configuring the Syslog Server

Follow the guidelines in this section when configuring the syslog server for Cisco ACI Virtual Edge.

  • The syslog server should always be reachable from the Cisco ACI Virtual Edge host management network or Cisco ACI Virtual Edge infra port group (overlay-1 vrf of tenant infra).

    If the syslog server is behind the Cisco ACI Virtual Edge, bring up the VM VNIC in the infra port group.

  • The syslog server should always be on a different host from Cisco ACI Virtual Edge.

    Sending log messages from a Cisco ACI Virtual Edge to a syslog server hosted behind the same Cisco ACI Virtual Edge is not supported.

  • If the syslog server destination is a VM, make sure that vMotion is disabled on it. If the syslog server destination VM is moved to another host for any reason, make sure that the static client endpoint (CEP) is configured accordingly. See the section Configure a Static End Point Using the GUI in this guide.

    The IP for the syslog server can be obtained using DHCP (Option 61 is needed during DHCP) or static configuration. Make sure that the IP address is in the same subnet as the other EPs in infra port group (overlay-1 VRF of tenant infra).

Distributed Firewall Flow Syslog Messages

This section provides the formats and examples of syslog messages for distributed Firewall flows.

  • Denied flows

    • Format
      <Syslog Server timestamp>  < PRI = Facility*8 + Severity > <syslog version>  <Host timestamp> <Host IP>  <Application name (ave-dfwlog)> - AVE IP: <AVEIP> AVE Hostname <hostname> DFWLOG-DENY_FLOW - <Deny Reason> AVE UUID: <UUID>, Source IP: <Source IP address>, Destination IP: <Destination IP address> , Source Port: <Port number>, Destination Port: <Port Number>, Source Interface: <Interface name>, Protocol: "TCP"(6), Hit-Count = <Number of Occurrences>, EPG Name: <EPG Name>, EpP DN: <EpP DN>
    • Example 
      Thu Apr 21 14:36:45 2016 10.197.139.205 <62>1 2017-12-06T18:58:30.835 10.197.139.205 ave-dfwlog - AVE IP: 10.197.139.205  AVE Hostname localhost, DFWLOG-DENY_FLOW - SYN ACK ingress AVE UUID: 42094298-4996-60EF-CE86-E2B7FC70C2EC, Source IP: 54.0.0.5, Destination IP: 54.0.0.6, Source Port: 53535, Destination Port: 5555, Source Interface: 00:50:56:89:4d:3e, Protocol: "TCP"(6), Hit-Count = 1, EPG Name = Tenant1|AP-1|EPG-54, EpP DN: uni/epp/fv-[uni/tn-Tenant1/ap-AP-1/epg-EPG-54]

  • Permitted flows

    • Format 

      <Syslog server timestamp> < PRI = Facility*8 + Severity> <syslog version> <Host timestamp> <Host IP>  <Application name (ave-dfwlog)> - AVE IP: <AVEIP> AVE Hostname <hostname> DFWLOG-PERMIT_FLOW -<flow status>  AVE UUID: <UUID>, Source IP: <Source IP address>, Destination IP: <Destination IP address>, Source Port: <Port Number>, Destination Port: <Port Number>, Source Interface: <Interface name>, Protocol: "TCP"(6), Age = <Age in seconds>, EPG Name: <EPG Name>, EpP DN: <EpP DN>
    • Example 
      Tue Apr 19 19:31:21 2016 10.197.139.205 <62>1 2017-12-06T18:45:13.458 10.197.139.205 ave-dfwlog - AVE IP: 10.197.139.205  AVE Hostname localhost, DFWLOG-PERMIT_FLOW - ESTABLISHED AVE UUID: 42094298-4996-60EF-CE86-E2B7FC70C2EC, Source IP: 54.0.0.5, Destination IP: 54.0.0.6, Source Port: 59846, Destination Port: 5001, Source Interface: 00:50:56:89:4d:3e, Protocol: "TCP"(6), Age = 0, EPG Name = Tenant1|AP-1|EPG-54, EpP DN: uni/epp/fv-[uni/tn-Tenant1/ap-AP-1/epg-EPG-54]

  • Short-lived permitted flows

    • Format 
      <Syslog Server timestamp>  < PRI = Facility*8 + Severity > <syslog version>  <Host timestamp> <Host IP>  <Application name (ave-dfwlog)> - AVE IP: <AVEIP> AVE Hostname <hostname> DFWLOG-PERMIT_SHORT_LIVED - <State of flow> AVE UUID: <UUID>, Source IP: <Source IP address>, Destination IP: <Destination IP address>, Source Port: <Port Number>, Destination Port: <Port Number>, Source Interface: <Interface Name>, Protocol: "TCP"(6), Timestamp = <Host Timestamp>, EPG Name: <EPG Name>, EpP DN: <EpP DN>
    • Example 
      Thu Apr 21 14:46:38 2016 10.197.139.205 <62>1 2017-12-06T18:59:37.702 10.197.139.205 ave-dfwlog - AVE IP: 10.197.139.205  AVE Hostname localhost, DFWLOG-PERMIT_SHORT_LIVED - CLOSED AVE UUID: 42094298-4996-60EF-CE86-E2B7FC70C2EC, Source IP: 54.0.0.5, Destination IP: 54.0.0.6, Source Port: 59847, Destination Port: 5001, Source Interface: 00:50:56:89:4d:3e, Protocol: "TCP"(6), Timestamp = 2017-12-06T18:59:37.702, EPG Name = Tenant1|AP-1|EPG-54, EpP DN: uni/epp/fv-[uni/tn-Tenant1/ap-AP-1/epg-EPG-54]

  • ICMP monitored flows

    • Format
      <Syslog server timestamp> < PRI = Facility*8 + Severity> <syslog version> <Host
timestamp> <Host IP> <Application name (ave-dfwlog)> - AVE IP: <AVEIP> AVE Hostname <hostname>
DFWLOG-ICMP_TRACKING - AVE UUID: <UUID>, Source IP: <Source IP address>,
Destination IP: <Destination IP address>, Type:<ICMP type field>, Source Interface:
<Interface name>, Protocol: "ICMP"(1), Timestamp= <Host time stamp>, Direction: <Egress/Ingress>, EPG Name:<EPG Name>, EpP DN: <EpP DN>
    • Example
      2016-11-28 11:02:43	News.Info	10.197.139.205	2017-12-06T19:01:05.061 10.197.139.205 ave-dfwlog - AVE IP: 10.197.139.205  AVE Hostname localhost, DFWLOG-ICMP_TRACKING AVE UUID: 42094298-4996-60EF-CE86-E2B7FC70C2EC, Source IP: 54.0.0.5, Destination IP: 54.0.0.6, Icmp type and code: Echo request (8,0) Source Interface: 00:50:56:89:4d:3e, Protocol: "ICMP"(1), Timestamp = 2017-12-06T19:01:05.061, Direction: Ingress, EPG Name = Tenant1|AP-1|EPG-54, EpP DN: uni/epp/fv-[uni/tn-Tenant1/ap-AP-1/epg-EPG-54]

  • UDP monitored flows

    • Format
      UDP: 
<Syslog server timestamp> < PRI = Facility*8 + Severity> <syslog version> <Host timestamp> <Host IP> <Application name (ave-dfwlog)> - AVE IP: <AVEIP> AVE Hostname <hostname> DFWLOG-UDP_TRACKING - AVE UUID: <UUID>, Source IP: <Source IP address>, Destination IP: <Destination IP address>, Source Port: <Port Number>, Destination Port: <Port Number>, Source Interface: <Interface name>, Protocol: "UDP"(17), Timestamp=<Host timestamp>, Direction: <Egress/Ingress>, EPG Name: <EPG Name>
    • Example
      2016-11-28 11:00:23	News.Info	10.197.139.205	1 2017-12-06T19:01:46.785 10.197.139.205 ave-dfwlog - AVE IP: 10.197.139.205  AVE Hostname localhost, DFWLOG-UDP_TRACKING AVE UUID: 42094298-4996-60EF-CE86-E2B7FC70C2EC, Source IP: 55.0.0.253, Destination IP: 55.0.0.5, Source Port: 67, Destination Port: 68, Source Interface: 00:50:56:00:55:05, Protocol: "UDP"(17), Timestamp = 2017-12-06T19:01:46.785, Direction: Egress, EPG Name = Tenant1|AP-1|EPG-55, EpP DN: uni/epp/fv-[uni/tn-Tenant1/ap-AP-1/epg-EPG-55]

Configure a Static End Point Using the GUI

Procedure

Step 1

Log in to Cisco APIC.

Step 2

In the Tenant infra navigation pane, open the following folders: Application Profiles > access > Application EPGs > default.

Step 3

Right-click the Static EndPoint folder and then choose Create Static EndPoint.

Step 4

In the Create Static Endpoint dialog box, complete the following steps:

  1. In the MAC field, enter the syslog server destination's MAC address.

  2. In the Type area, choose tep.

  3. In the Path Type area, choose the appropriate path type.

    The path type determines how the leaf is connected to the syslog server destination. The leaf can be connected by port, direct port channel, or virtual port channel.

  4. If you chose Port as the Path Type, choose a node from the Node drop-down list.

  5. In the Path field, enter the appropriate path.

    The path determines the policy group where the syslog server destination is attached.

  6. In the IP Address field, enter the syslog server destination IP address.

  7. In the Encap field, enter the overlay-1 VLAN (vlan-xxix).

  8. Click Submit.

Step 5

From the syslog server destination, ping any overlay-IP address—for example, 10.0.0.30.

This step ensures that the fabric learns the Syslog server destination IP address.

Configure Parameters for Distributed Firewall Flow Information Using the GUI

To configure parameters, you first configure the parameters for the syslog server or servers and then configure the parameters for the syslog policy. The syslog server is referred to as the Remote Destination in the GUI.

Before you begin

You must have Distributed Firewall enabled.

Procedure

Step 1

Log in to Cisco APIC.

Step 2

Go to Admin > External Data Collectors.

Step 3

In the External Data Collectors navigation pane, expand the Monitoring Destinations folder and then choose the Syslog folder.

Step 4

In the Syslog work pane, click the ACTIONS down arrow and then choose Create Syslog Monitoring Destination Group.

Step 5

In the Create Syslog Monitoring Destination Group STEP 1 > Profile dialog box, complete the following steps:

  1. In the Define Group Name and Profile area, enter a name in the Name field.

  2. In the Admin State area, make sure that enabled is chosen from the drop-down list.

  3. Accept the defaults in the rest of the dialog box and click NEXT.

Step 6

In the Create Syslog Monitoring Destination Group STEP 2 > Remote Destinations dialog box, click the + icon.

Step 7

In the Create Syslog Remote Destination dialog box, complete the following steps:

  1. In the Host field, enter the host IP address.

  2. In the Name field, enter the host name.

  3. In the Admin State area, make sure that enabled is chosen.

  4. In the Format area, make sure that aci is chosen.

  5. From the Severity drop-down list, choose a severity.

  6. From the Port drop-down list, accept the standard port unless you are using another port.

  7. From the Forwarding Facility drop-down list, choose a facility.

  8. Ignore the Management EPG drop-down list and click OK.

Step 8

(Optional) In the Create Syslog Monitoring Destination Group STEP 2 > Remote Destinations dialog box, create up to two additional remote destinations.

Step 9

In the Create Syslog Monitoring Destination Group STEP 2 > Remote Destinations dialog box, click FINISH.

The newly created destination appears in the Syslog folder in the External Data Collectors navigation pane.

Step 10

Choose Fabric > Access Policies.

Step 11

In the Policies navigation pane, open the Polices and Interface folders.

Step 12

Complete one of the following sets of steps:

If you want to... Then...
Configure a syslog policy with a new Distributed Firewall policy

  1. Right-click the Firewall folder and choose Create Firewall Policy.

  2. In the Create Firewall Policy dialog box, in the Specify the Firewall Policy Properties area, type a name for the policy in the Name field.

  3. In the Mode area, choose a mode.

    Distributed Firewall must be in Learning mode if you migrate to Cisco ACI Virtual Edge from Cisco AVS if the version of Cisco AVS is earlier than Release 5.2(1)SV3(1.5). Those versions do not support Distributed Firewall.

  4. In the Syslog area, make sure that enabled is chosen from the Administrative State drop-down list.

  5. From the Included Flows area, choose Permitted flows, Denied flows, or both.

  6. In the Polling Interval (seconds) area, choosing an interval from 60 seconds to 24 hours.

  7. From the Log Level drop-down list, choose a severity level.

    The logging severity level should be greater than or equal to severity level defined for the syslog server. See the section Parameters for Distributed Firewall Flow Information in this guide for information about severity.

  8. From the Dest Group drop-down list, choose the destination group that you just created.

  9. Click Submit.

  10. Go to the section "What To Do Next" and associate the new Distributed Firewall policy with a VMM domain.

Configure a syslog policy with an existing Distributed Firewall policy

  1. Expand the Firewall folder and choose the Distributed Firewall policy that you want to modify.

  2. In the policy work pane, change the Mode if desired.

    Distributed Firewall must be in Learning mode if you migrate to Cisco ACI Virtual Edge from Cisco AVS if the version of Cisco AVS is earlier than Release 5.2(1)SV3(1.5). Those versions do not support Distributed Firewall.

  3. In the Syslog area, make sure that enabled is chosen from the Administrative State drop-down list.

  4. From the Included Flows area, choose Permitted flows, Denied flows, or both.

  5. In the Polling Interval (seconds) area, choosing an interval from 60 seconds to 24 hours.

  6. From the Log Level drop-down list, choose a severity level.

    The logging severity level should be greater than or equal to severity level defined for the syslog server. See the section Parameters for Distributed Firewall Flow Information in this guide for information about severity.

  7. From the Dest Group drop-down list, choose the destination group that you just created.

  8. Click Submit.

  9. If you see the Policy Usage Warning dialog box, click SUBMIT CHANGES.

What to do next

If you configured a syslog policy with a new Distributed Firewall policy, you must associate the Distributed Firewall policy with a VMM domain.

  1. In Cisco APIC, choose Virtual Networking > Inventory.

  2. In the navigation pane, expand the VMM Domains folder and the VMware folder, and then choose the relevant VMM domain.

  3. In the work pane, click the VSwitch Policy tab under the Policy tab.

  4. In the Create VSwitch Policy Container dialog box, click Yes.

  5. In the work pane, from the Firewall Policy drop-down list, choose the policy.

  6. Click Submit.

  7. If you see the Policy Usage Warning dialog box, click SUBMIT CHANGES.

Distributed Firewall Flow Counts

You can view Distributed Firewall flow counts with the Cisco APIC.

Cisco ACI Virtual Edge collects Distributed Firewall flow information, but you must choose which statistics you want to know about before you can view them. You can choose a sampling interval with choices ranging from 10 seconds to 1 year; however, the default is 5 minutes.

You can choose statistics and view them from two different places in Cisco APIC: one beginning with Virtual Networking and one beginning with Tenants. However, the steps for choosing and viewing statistics are the same.

When you choose statistics in Cisco APIC, you see a list of different kinds of statistics, but only nine are relevant to Distributed Firewall:

  • aged connections (connections)

  • created connections (connections)

  • destroyed connections (connections)

  • denied global input connections (connections)

  • denied per port limit connections (connections)

  • invalid SYN ACK packets (packets)

  • invalid SYN packets (packets)

  • invalid connection packets (packets)

  • invalid ftp SYN packets (packets)

Choose Statistics to View for Distributed Firewall

Before you begin

You must have Distributed Firewall enabled.

Procedure

Step 1

Choose Virtual Networking > Inventory > VMM Domains > VMware > VMM_name > Controllers > controller instance name > DVS-VMM name > Portgroups > EPG_name > Learned Point MAC address (Node).

Step 2

Click the Stats tab.

Step 3

Click the tab with the check mark.

Step 4

In the Select Stats dialog box, click the statistics that you want to view in the Available pane and then click the arrow pointing right to put them in the Selected pane.

Step 5

(Optional) Choose a sampling interval.

Step 6

Click Submit.

View Statistics for Distributed Firewall

Once you have chosen statistics for Distributed Firewall, you can view them.

Before you begin

You must have chosen statistics to view for Distributed Firewall.

Procedure

Step 1

Choose Virtual Networking > Inventory > VMware > VMM Domains > VMM_name > Controllers > controller instance name > DVS-VMM name > Portgroups > EPG_name > Learned Point MAC address (Node)

Step 2

Click the Stats tab.

The central pane displays the statistics that you chose earlier. You can change the view by clicking the table view or chart view icon on the upper left side of the work pane.