Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 
 

Tunnel Inspection for EVPN-VXLAN by SRX Series Devices

SUMMARY Read this topic to understand how to setup your security device to perform tunnel inspection for EVPN-VXLAN to provide embedded security.

Overview

(Ethernet VPN) EVPN-(Virtual Extensible LAN) VXLAN provides enterprises a common framework used to manage their campus and data center networks.

The rapidly increasing usage of mobile and IoT devices adds a large number of endpoints to a network. Modern enterprise networks must scale rapidly to provide immediate access to devices and to extend security and control for these endpoints.

To provide endpoint flexibility, EVPN-VXLAN decouples the underlay network (physical topology) from the overlay network (virtual topology). By using overlays, you gain the flexibility of providing Layer 2/Layer 3 connectivity between endpoints across campus and data centers, while maintaining a consistent underlay architecture.

You can use SRX Series devices in your EVPN-VXLAN solution to connect end-points in your campus, data center, branch and public cloud environments while providing embedded security.

Starting in Junos OS Release 21.1R1, the SRX Series device can also apply following Layer 4/Layer 7 security services to the EVPN-VXLAN tunnel traffic:

  • Application Identification

  • IDP

  • Juniper ATP (formerly known as SKY ATP)

  • UTM

Figure 1 shows a typical deployment scenario of EVPN-VXLAN fabric based on Edge-routed bridging (ERB) with SRX Series devices functioning in an enhanced border leaf (EBL) role. EBL enhances the traditional role of a border leaf with the ability to perform inspection of traffic in VXLAN tunnels.

Figure 1: EVPN-VXLAN Architecture with SRX Series Device EVPN-VXLAN Architecture with SRX Series Device

In the figure VXLAN traffic originating at the leaf 1 device traverses through the SRX Series devices that function as EBLs. In this use case, the SRX Series device is placed at the border, that is, at the entry and exit point of the campus or data center, to provide stateful inspection to the VXLAN encapsulated packets traversing through it.

In the architecture diagram, you can notice that an SRX Series device is placed between two VTEP devices (devices that perform VXLAN encapsulation and decapsulation for the network traffic). The SRX Series device performs stateful inspection when you enable the tunnel inspection feature with an appropriate security policy.

Benefits

Adding SRX Series device in EVPN VXLAN provides:

  • Added security with the capabilities of an enterprise grade firewall in the EVPN-VXLAN overlay.
  • Enhanced tunnel inspection for VXLAN encapsulated traffic with Layer 4/Layer 7 security services.

Example - Configure Security Policies for EVPN-VXLAN Tunnel Inspection

Use this example to configure the security policies that enable inspection of EVPN EVPN-VXLAN tunnel traffic on your SRX Series devices.

Requirements

This example uses the following hardware and software components:

  • An SRX Series device or vSRX
  • Junos OS Release 20.4R1

This example assumes that you already have an EVPN-VXLAN based network and want to enable tunnel inspection on SRX Series device.

Before you Begin

  • Ensure you have a valid application identification feature license on your SRX Series device and installed application signature pack on the device.
  • Make sure you understand how EVPN and VXLAN works. See EVPN-VXLAN Campus Architectures to detail understanding EVPN-VXLAN
  • This example assumes that you already have an EVPN-VXLAN based network fabric and want to enable tunnel inspection on the SRX Series device. You can see the sample configuration of leaf and spine devices used in this example at Complete Device Configurations.

In this example, we are focusing on configuring the SRX Series device which is a part of a working EVPN-VXLAN network that consist of two DC locations each with an IP fabric. The SRX Series device is placed in a Data Center Interconnect (DCI) role between the two DCs. In this configuration, the SRX Series device performs stateful inspection of VXLAN encapsulated traffic flowing between the DCs when you enable tunnel inspection.

We are using the topology shown in Figure 2 in this example.

Overview

Figure 2: Topology for VXLAN Tunnel Inspection Topology for VXLAN Tunnel Inspection

As given in the topology, the SRX Series device is inspecting transit VLAN encapsulated traffic from the VXLAN tunnel endpoint (VTEP) on the leaves in both the DC-1 and DC-2 data centers. Any Juniper Networks device, both physical and virtual, that functions as a Layer 2 or Layer 3 VXLAN gateway can act as VTEP device to perform encapsulation and de-encapsulation.

Upon receipt of a Layer 2 or Layer 3 data packet from server 1, The leaf 1 VTEP adds the appropriate VXLAN header and then encapsulates the packet with a IPv4 outer header to facilitate tunneling the packet through the IPv4 underlay network. The remote VTEP at leaf 2 then de-encapsulates the traffic and forwards the original packet towards the destination host. With the Junos software release 20.4 SRX Series devices are able to perform tunnel inspection for VXLAN encapsulated overlay traffic passing through it.

In this example, you’ll create a security policy to enable inspection for traffic that is encapsulated in a VXLAN tunnel . We're using the parameters described Table 1 in this example.

Table 1: Configuration Parameters
Parameter Description Parameter Name
Security policy Policy to create a flow session triggered by VXLAN overlay traffic. This policy references the outer IP source and destination address. That is, the IP addresses of the source and destination VTEPs. In this example this is the loopback address of the leaves. P1
Policy set Policy for the inspection of inner traffic. This policy operates on the contents of matching VXLAN tunnel traffic. PSET-1
Tunnel inspection profile Specifies parameters for security inspection on VXLAN tunnels. TP-1
Name of a VXLAN network identifier (VNI) list or range Used to uniquely identify a list or range of VXLAN tunnel IDs. VLAN-100
VXLAN tunnel identifier name. Used to symbolically name a VXLAN tunnel in a tunnel inspection profile. VNI-1100

When you configure tunnel inspection security policies on the SRX Series device, it decapsulates the packet to access the inner header when a packet matches a security policy. Next, it applies the tunnel inspection profile to determine if the inner traffic is permitted. The security device uses inner packet content and the applied tunnel inspection profile parameters to do a policy lookup and to then perform stateful inspection for the inner session.

Configuration

In this example, you'll configure the following functionality on the SRX Series device:

  1. Define a trust and untrust zone to permit all host traffic. This supports the BGP session to the spine devices and allow SSH etc from either zone (DC).
  2. Inspect traffic flowing from DC1 to DC2 in VNI 1100 (Layer 2 stretched for VLAN 100) for all hosts in the 192.168.100.0/24 subnet. Your policy should permit pings but deny all other traffic.
  3. Allow all return traffic from DC2 to DC1 with no tunnel inspection.
  4. Allow all other underlay and overlay traffic without VXLAN tunnel inspection from DC1 to DC2.

Use the following steps to enable tunnel inspection on your security device in a VXLAN-EVPN environment:

Note:

Complete functional configurations for all devices used in this example are provided Complete Device Configurations to assist the reader in testing this example.

This example focuses on the configuration steps needed to enable and validate the VXLAN tunnel inspection feature. The SRX device is presumed to be configured with interface addressing, BGP peering, and policy to support its DCI role.

CLI Quick Configuration

To quickly configure this example on your SRX series device , copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

Configuration on SRX Series Device

Step-by-Step Procedure

  1. Configure security zones, interfaces, and address-books. Note that /24 prefix lengths are used to specify the outer (VTEP) and inner (server) addresses. While you could use /32 host routes for this simple example, using a /24 will match traffic from other leaves (VTEPs) or hosts in the 192.168.100/0/24 subnet.
  2. Define the tunnel-inspection profile. You can specify a range or a list of VNIs that should be inspected.

    In this example only one VNI is needed so the vni-id keyword is used instead of the vni-range option.

    The tunnel inspection profile links to both the VNI list/range as well as to the related policy that should be applied to VXLAN tunnel with matching VNIs.
  3. Create a security policy to match on the outer session. This policy refers to the global address book entries you defined earlier to match source and destination VTEP addresses. These addresses are used in the underlay to support VXLAN tunnels in the overlay. Matching traffic is directed to the TP-1 tunnel inspection profile you defined in the previous step. In this example the goal is to inspect VXLAN tunnels that originate in DC1 and terminate in DC2. As a result a second policy to match on return traffic (with DC2 Leaf 1 the source VTEP) is not needed.
  4. Create the policy-set for the inner session.

    This policy performs security inspection against the payload of matching VXLAN traffic. In this example this is the traffic sent from Server 1 on VLAN 100 in DC1 to Server 1 in DC2. By specifying the junos-icmp-all match condition you ensure that both ping request and replies can pass from server 1 ion DC1 to server 1 in DC2. If you specify junos-icmp-ping only pings that originate from DC1 will be permitted.

    Recall that in this example only ping is permitted to help facilitate testing of the resulting functionality. You can match on application any to permit all traffic, or alter the match criteria to suit your specific security needs.

  5. Define the policies needed to accept all other traffic between the data centers without any tunnel inspection.

Results

From configuration mode, confirm your configuration by entering the show security command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

[edit]

user@host# show security

If you are done configuring the feature on your device, enter commit from configuration mode.

Verification

At this time you should generate ping traffic between server 1 in DC1 to server 1 in DC2. The pings should succeed. Allow this test traffic to run in the background while you complete the verification tasks.

Verify Inner Policy Details

Purpose

Verify the details of the policy applied for the inner session.

Action

From operational mode, enter the show security policies policy-set PSET-1 command.

Check Tunnel Inspection Traffic

Purpose

Display the tunnel inspection traffic details.

Action

From operational mode, enter the show security flow tunnel-inspection statistics command.

Check Tunnel Inspection Profile and VNI

Purpose

Display the tunnel inspection profile and VNI details.

Action

From operational mode, enter the show security tunnel-inspection profiles command.

From operational mode, enter the show security tunnel-inspection vnis command.

Check Security Flows

Purpose

Display VXLAN security flow information on the SRX to confirm that VXLAN tunnel inspection is working.

Action

From operational mode, enter the show security flow session vxlan-vni 1100 command.

Confirm That SSH is Blocked

Purpose

Try to establish an SSH session between server 1 in DC1 and server 2 in DC2. Based on the policy that allows only ping traffic this session should be blocked at the SRX.

Action

From operational mode, enter the show security flow session vxlan-vni 1100 command.

Configuration for Zone-Level Inspection, IDP, UTM and Advanced Anti-Malware for Tunnel Inspection

Use this step if you want to configure zone-level inspection, and apply layer 7 services such as IDP, Juniper ATP, UTM, and advanced anti-malware to the tunnel traffic. This feature is supported from Junos OS Release 21.1R1 onwards.

This example uses the following hardware and software components:

  • An SRX Series device or vSRX
  • Junos OS Release 21.1R1

We are using the same configuration of address-books, security zones, interfaces, tunnel inspection profile, and security policy for the outer session as created in Configuration

This step assumes that you have Enrolled your SRX Series device with Juniper ATP. For details on how to enroll your SRX Series device, see Enrolling an SRX Series Device With Juniper Advanced Threat Prevention Cloud.

In this configuration, you'll create a policy set for the inner session and apply IDP, UTM, advanced antimalware to the tunnel traffic.

CLI Quick Configuration

To quickly configure this example on your SRX series device , copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

Configuration on SRX Series Device

Create Zone-Level Inspection for Tunnel Inspection

You can add zone-level policy control for EVPN-VXLAN tunnel inspection for the inner traffic. This policy performs security inspection against the payload of matching VXLAN traffic. In the following step, you'll specify from-zone and to-zone for the traffic.

Create IDP, UTM and Advanced Anti-Malware for Tunnel Inspection

You can add security services such as IDP, advanced aniti-malware, UTM, SSL proxy for the EVPN-VXLAN tunnel inspection for the inner traffic. This policy performs security inspection against the payload of matching VXLAN traffic.

In the following step, you'll enable service such as IDP, UTM, SSL proxy, security-intelligence, advanced anti-malware services by specifying them in a security policy permit action, when the traffic matches the policy rule.

The following steps show configuration snippets of UTM, IDP, and advanced anti-malware policies at-glance.

  • Configure advanced anti-malware policy.

  • Configure security intelligence profile.

  • Configure IDP policy.

  • Configure UTM policy.

  • Configure SSL profiles.

Results

From configuration mode, confirm your configuration by entering the show security command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

[edit]

user@host# show security

[edit]

user@host# show services

If you are done configuring the feature on your device, enter commit from configuration mode.

Complete Device Configurations

Refer to these configurations to better understand or recreate the context of this example. They include the complete ERB based EVPN-VXLAN configurations for the QFX Series switches that form the DC fabrics, as well as the ending state of the SRX Series device for both the basic and advanced VXLAN tunnel inspection examples.

Note:

The provided configurations do not show user login, system logging, or management related configuration as this varies by location is not related to the VXLAN tunnel inspection feature.

For more details and example on configuring EVPN-VXLAN, see the network configuration example at Configuring an EVPN-VXLAN Fabric for a Campus Network with ERB.

Configuration on Leaf 1 Device

Configuration on Spine 1 Device

Configuration on Leaf 2 Device

Configuration on Spine 2 Device

Basic Tunnel Inspection Configuration on SRX Series Device

Tunnel Inspection Configuration on SRX Series Device with Layer 7 Security Services