Example for Configuring Dynamic VXLAN in an Active-Active Scenario (Layer 3 Communication)

In a scenario where a data center is interconnected with an enterprise site, a CE is dual-homed to a VXLAN network. Carriers can enhance VXLAN access reliability to improve the stability of user services so that rapid convergence can be implemented in the case of a fault.

Networking Requirements

On the network shown in Figure 1, a VXLAN tunnel is required to be dynamically deployed using BGP EVPN between the CPE and the PE1-PE2 pair. An EVPN peer relationship needs to be established between PE1 and PE2 to deploy a bypass VXLAN tunnel. In addition, a CE needs to be dual-homed to PE1 and PE2 that are configured with the same anycast VTEP address to implement the active-active function. If one of the PEs fails, this function allows traffic to be quickly switched to the other PE.

Figure 1 Networking for configuring dynamic VXLAN in an active-active scenario

Interfaces 1 through 3 in this example represent GE 0/1/1, GE 0/1/2, and GE 0/1/3, respectively.

**Table 1** Interface IP addresses
Device	Interface	IP Address
PE1	GE 0/1/1	10.1.20.1/24
	GE 0/1/2	-
	GE 0/1/3	10.1.1.1/24
	Loopback 1	1.1.1.1/32
	Loopback 2	3.3.3.3/32
PE2	GE 0/1/1	10.1.20.2/24
	GE 0/1/2	-
	GE 0/1/3	10.1.2.1/24
	Loopback 1	2.2.2.2/32
	Loopback 2	3.3.3.3/32
CE	GE 0/1/1	-
CE	GE 0/1/2	-
CPE	GE 0/1/1	10.1.1.2/24
	GE 0/1/2	10.1.2.2/24
	Loopback 1	4.4.4.4/32

Configuration Roadmap

The configuration roadmap is as follows:

Configure a routing protocol on the CPE and each PE for the devices to communicate at Layer 3. In this example, an IGP is configured.
Configure CE1 to be dual-homed to PE1 and PE2 through Eth-Trunk Layer 2 sub-interfaces.
Configure EVPN instances on PE1, PE2, and the CPE.
Configure VPN instances on PE1, PE2, and the CPE.
Configure VBDIF interfaces on PE1 and PE2 for Layer 3 access.
Configure the same virtual anycast VTEP address on PE1 and PE2 as the source NVE interface address of the VXLAN tunnel to be established with the CPE. Create a VXLAN tunnel between the CPE and the PE1-PE2 pair using BGP EVPN, allowing the CPE to communicate with the PEs.
Enable the inter-chassis VXLAN function on PE1 and PE2, configure different bypass addresses for the PEs, establish a BGP EVPN peer relationship, and create a bypass VXLAN tunnel between the PEs, allowing the PEs to communicate with each other.
Enable auto FRR in the BGP VPN address family view on PE1 and PE2. In this way, if a PE fails, the downstream traffic of the CPE can be quickly switched to the other PE and then forwarded to a CE.

Procedure

Assign IP addresses to device interfaces, including loopback interfaces.
For configuration details, see Configuration Files in this section.
Configure an IGP. In this example, IS-IS is used.
For configuration details, see Configuration Files in this section.

Configure PE1 and PE2 to provide dual-homing access for CE1 through Eth-Trunk Layer 2 sub-interfaces.

# Configure PE1.

<PE1> system-view
[~PE1] interface eth-trunk 10
[*PE1-Eth-Trunk10] trunkport gigabitethernet 0/1/2
[*PE1-Eth-Trunk10] esi 0000.0000.0000.0000.1111
[*PE1-Eth-Trunk10] quit
[*PE1] bridge-domain 10
[*PE1-bd10] vxlan vni 10 split-horizon-mode
[*PE1-bd10] quit
[*PE1] interface eth-trunk 10.1 mode l2
[*PE1-Eth-Trunk10.1] encapsulation dot1q vid 10
[*PE1-Eth-Trunk10.1] rewrite pop single
[*PE1-Eth-Trunk10.1] bridge-domain 10
[*PE1-Eth-Trunk10.1] quit
[*PE1] commit

# Configure PE2.

<PE2> system-view
[~PE2] interface eth-trunk 10
[*PE2-Eth-Trunk10] trunkport gigabitethernet 0/1/2
[*PE2-Eth-Trunk10] esi 0000.0000.0000.0000.1111
[*PE2-Eth-Trunk10] quit
[*PE2] bridge-domain 10
[*PE2-bd10] vxlan vni 10 split-horizon-mode
[*PE2-bd10] quit
[*PE2] interface eth-trunk 10.1 mode l2
[*PE2-Eth-Trunk10.1] encapsulation dot1q vid 10
[*PE2-Eth-Trunk10.1] rewrite pop single
[*PE2-Eth-Trunk10.1] bridge-domain 10
[*PE2-Eth-Trunk10.1] quit
[*PE2] commit

Enable the inter-chassis VXLAN function.
# Configure PE1.
```
[~PE1] evpn
[*PE1-evpn] bypass-vxlan enable
[*PE1-evpn] quit
[*PE1] commit
```
The configuration of PE2 is similar to the configuration of PE1. For configuration details, see Configuration Files in this section.

Configure EVPN instances.

# Configure the CPE.

<CPE> system-view
[~CPE] evpn vpn-instance evrf1 bd-mode
[*CPE-evpn-instance-evrf1] route-distinguisher 11:11
[*CPE-evpn-instance-evrf1] vpn-target 1:1 import-extcommunity
[*CPE-evpn-instance-evrf1] vpn-target 1:1 export-extcommunity
[*CPE-evpn-instance-evrf1] quit
[*CPE] bridge-domain 10
[*CPE-bd10] vxlan vni 10 split-horizon-mode
[*CPE-bd10] evpn binding vpn-instance evrf1
[*CPE-bd10] quit
[*CPE] commit

# Configure PE1.

[~PE1] evpn vpn-instance evrf1 bd-mode
[*PE1-evpn-instance-evrf1] route-distinguisher 11:11
[*PE1-evpn-instance-evrf1] vpn-target 1:1 import-extcommunity
[*PE1-evpn-instance-evrf1] vpn-target 1:1 export-extcommunity
[*PE1-evpn-instance-evrf1] quit
[*PE1] bridge-domain 10
[*PE1-bd10] evpn binding vpn-instance evrf1
[*PE1-bd10] quit
[*PE1] commit