Example for Configuring Users on Different Network Segments to Communicate Through a VXLAN Layer 3 Gateway

This section provides an example for configuring users on different network segments to communicate through a VXLAN Layer 3 gateway. To achieve this, the default gateway address of the users must be the IP address of the BDIF interface of the Layer 3 gateway.

Networking Requirements

On the network shown in Figure 1, an enterprise has VMs deployed in different data centers. VM1 on Server1 belongs to VLAN10, and VM1 on Server2 belongs to VLAN20. VM1 on Server1 and VM1 on Server2 reside on different network segments. To allow VM1s in different data centers to communicate with each other, configure a VXLAN tunnel between Device1 and Device2 and one between Device2 and Device3.

Figure 1 Configuring users on different network segments to communicate through a VXLAN Layer 3 gateway

Interfaces 1 and 2 represent GE 0/1/1 and GE 0/1/2, respectively.

Configuration Roadmap

The configuration roadmap is as follows:

Configure a routing protocol on Device1, Device2, and Device3 to allow them to communicate at Layer 3.
Configure a service access point on Device1 and Device3 to differentiate service traffic.
Configure a VXLAN tunnel on Device1, Device2, and Device3 to forward service traffic.
Configure Device2 as a VXLAN Layer 3 gateway to allow users on different network segments to communicate.

Data Preparation

To complete the configuration, you need the following data:

VMs' VLAN IDs (10 and 20)
IP addresses of interfaces connecting devices
Interior Gateway Protocol (IGP) running between devices (OSPF in this example)
BD IDs (10 and 20)
VNI IDs (5010 and 5020)

Procedure

Configure a routing protocol.

Assign an IP address to each interface on Device1, Device2, and Device3 according to Figure 1.

# Configure Device1.

<HUAWEI> system-view
[~HUAWEI] sysname Device1
[*HUAWEI] commit
[~Device1] interface loopback 1
[*Device1-LoopBack1] ip address 2.2.2.2 32
[*Device1-LoopBack1] quit
[*Device1] interface gigabitethernet 0/1/1
[*Device1-GigabitEthernet0/1/1] ip address 192.168.1.1 24
[*Device1-GigabitEthernet0/1/1] quit
[*Device1] ospf
[*Device1-ospf-1] area 0
[*Device1-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0
[*Device1-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
[*Device1-ospf-1-area-0.0.0.0] quit
[*Device1-ospf-1] quit
[*Device1] commit

Repeat these steps for Device2 and Device3. For configuration details, see Configuration Files in this section.

After OSPF is configured, the devices can use OSPF to learn the IP addresses of loopback interfaces of each other and successfully ping each other. The following example shows the command output on Device1 after it pings Device3:

[~Device1] ping 4.4.4.4
  PING 4.4.4.4: 56  data bytes, press CTRL_C to break
    Reply from 4.4.4.4: bytes=56 Sequence=1 ttl=254 time=5 ms
    Reply from 4.4.4.4: bytes=56 Sequence=2 ttl=254 time=2 ms
    Reply from 4.4.4.4: bytes=56 Sequence=3 ttl=254 time=2 ms
    Reply from 4.4.4.4: bytes=56 Sequence=4 ttl=254 time=3 ms
    Reply from 4.4.4.4: bytes=56 Sequence=5 ttl=254 time=3 ms

  --- 4.4.4.4 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 2/3/5 ms

Configure a service access point on Device1 and Device3.

# Configure Device1.

[~Device1] bridge-domain 10
[*Device1-bd10] quit
[*Device1] interface gigabitethernet0/1/2.1 mode l2
[*Device1-GigabitEthernet0/1/2.1] encapsulation dot1q vid 10
[*Device1-GigabitEthernet0/1/2.1] rewrite pop single
[*Device1-GigabitEthernet0/1/2.1] bridge-domain 10
[*Device1-GigabitEthernet0/1/2.1] quit
[*Device1] commit

Repeat these steps for Device3. For configuration details, see Configuration Files in this section.

Configure a VXLAN tunnel on Device1, Device2, and Device3.

# Configure Device1.

[~Device1] bridge-domain 10
[*Device1-bd10] vxlan vni 5010
[*Device1-bd10] quit
[*Device1] interface nve 1
[*Device1-Nve1] source 2.2.2.2
[*Device1-Nve1] vni 5010 head-end peer-list 3.3.3.3
[*Device1-Nve1] quit
[*Device1] commit

# Configure Device2.

[~Device2] bridge-domain 10
[*Device2-bd10] vxlan vni 5010
[*Device2-bd10] quit
[*Device2] interface nve 1
[*Device2-Nve1] source 3.3.3.3
[*Device2-Nve1] vni 5010 head-end peer-list 2.2.2.2
[*Device2-Nve1] quit
[~Device2] bridge-domain 20
[*Device2-bd20] vxlan vni 5020
[*Device2-bd20] quit
[*Device2] interface nve 1
[*Device2-Nve1] vni 5020 head-end peer-list 4.4.4.4
[*Device2-Nve1] quit
[*Device2] commit

# Configure Device3.

[~Device3] bridge-domain 20
[*Device3-bd20] vxlan vni 5020
[*Device3-bd20] quit
[*Device3] interface nve 1
[*Device3-Nve1] source 4.4.4.4
[*Device3-Nve1] vni 5020 head-end peer-list 3.3.3.3
[*Device3-Nve1] quit
[*Device3] commit

Configure Device2 as a VXLAN Layer 3 gateway.

[~Device2] interface vbdif 10
[*Device2-Vbdif10] ip address 192.168.10.10 24
[*Device2-Vbdif10] quit
[*Device2] interface vbdif 20
[*Device2-Vbdif20] ip address 192.168.20.10 24
[*Device2-Vbdif20] quit
[*Device2-Vbdif20] commit

Verify the configuration.
After completing the configurations, run the display vxlan vni and display vxlan tunnel commands on Device1, Device2, and Device3 to check the VNI status and VXLAN tunnel information, respectively. The VNIs are Up on Device1, Device2, and Device3. The following example shows the command output on Device2.
```
[~Device2] display vxlan vni
Number of vxlan vni: 2
VNI            BD-ID            State
---------------------------------------
5010           10               up
5020           20               up
[~Device2] display vxlan tunnel
Number of Vxlan tunnel : 2
Tunnel ID   Source           Destination        State  Type    Uptime
---------------------------------------------------------------------
4026531841  3.3.3.3          2.2.2.2            up     static 0029h30m
4026531842  3.3.3.3          4.4.4.4            up     static 0029h44m
```
VM1 in VLAN10 on Server1 has the default gateway address as the IP address 192.168.10.10/24 of BDIF10.

VM1 in VLAN20 on Server2 has the default gateway address as the IP address 192.168.20.10/24 of BDIF20.

Therefore, VM1s on different network segments can communicate. In addition, if Device1 and Device3 need to communicate at the overlay network layer, they can use static routes or an IGP to advertise routes to each other on network segments 192.168.10.0/24 and 192.168.20.0/24. The next hop is the VBDIF interface address on Device2.

Configuration Files

Device1 configuration file

#
sysname Device1
#
bridge-domain 10
 vxlan vni 5010
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 192.168.1.1 255.255.255.0
#
interface GigabitEthernet0/1/2
 undo shutdown
#
interface GigabitEthernet0/1/2.1 mode l2
 encapsulation dot1q vid 10
 rewrite pop single
 bridge-domain 10
#
interface LoopBack1
 ip address 2.2.2.2 255.255.255.255
#
interface Nve1
 source 2.2.2.2
 vni 5010 head-end peer-list 3.3.3.3
#
ospf 1
 area 0.0.0.0
  network 2.2.2.2 0.0.0.0
  network 10.1.1.0 0.0.0.255
  network 192.168.1.0 0.0.0.255
#
return

Device2 configuration file

#
sysname Device2
#
bridge-domain 10
 vxlan vni 5010
#
bridge-domain 20
 vxlan vni 5020
#
interface Vbdif10
 ip address 192.168.10.10 255.255.255.0
#
interface Vbdif20
 ip address 192.168.20.10 255.255.255.0
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 192.168.1.2 255.255.255.0
#
interface GigabitEthernet0/1/2
 undo shutdown
 ip address 192.168.2.1 255.255.255.0
#
interface LoopBack1
 ip address 3.3.3.3 255.255.255.255
#
interface Nve1
 source 3.3.3.3
 vni 5010 head-end peer-list 2.2.2.2
 vni 5020 head-end peer-list 4.4.4.4
#
ospf 1
 area 0.0.0.0
  network 3.3.3.3 0.0.0.0
  network 192.168.1.0 0.0.0.255
  network 192.168.2.0 0.0.0.255
#
return

Device3 configuration file

#
sysname Device3
#
bridge-domain 20
 vxlan vni 5020
#
interface GigabitEthernet0/1/1
 undo shutdown
 ip address 192.168.2.2 255.255.255.0
#
interface GigabitEthernet0/1/2
 undo shutdown
#
interface GigabitEthernet0/1/2.1 mode l2
 encapsulation dot1q vid 20
 rewrite pop single
 bridge-domain 20
#
interface LoopBack1
 ip address 4.4.4.4 255.255.255.255
#
interface Nve1
 source 4.4.4.4
 vni 5020 head-end peer-list 3.3.3.3
#
ospf 1
 area 0.0.0.0
  network 4.4.4.4 0.0.0.0
  network 10.2.1.0 0.0.0.255
  network 192.168.2.0 0.0.0.255
#
return