Static VXLAN Tunnels
In VXLAN-based networks, there are a range of complexities and challenges in determining the destination virtual tunnel endpoints (VTEPs) for any given VXLAN. At scale, various solutions, including Lightweight Network Virtualization (LNV), controller-based options like Midokura MidoNet or VMware NSX and even new standards like EVPN are attempts to address these complexities, however do retain their own complexities.
Enter static VXLAN tunnels, which simply serve to connect two VTEPs in a given environment. Static VXLAN tunnels are the simplest deployment mechanism for small scale environments and are interoperable with other vendors that adhere to VXLAN standards. Because you are simply mapping which VTEPs are in a particular VNI, you can avoid the tedious process of defining connections to every VLAN on every other VTEP on every other rack.
Cumulus Networks supports static VXLAN tunnels only on switches in the Cumulus Linux HCL using the Broadcom Tomahawk, Trident II+, Trident II, and Maverick ASICs, as well as the Mellanox Spectrum ASIC.
For a basic VXLAN configuration, make sure that:
- The VXLAN has a network identifier (VNI); do not use 0 or 16777215 as the VNI ID, which are reserved values under Cumulus Linux.
- The VXLAN link and local interfaces are added to bridge to create the association between port, VLAN, and VXLAN instance.
Each traditional bridge on the switch has only one VXLAN interface. Cumulus Linux does not support more than one VXLAN ID per traditional bridge.
When deploying VXLAN with a VLAN-aware bridge, there is no restriction on using a single VNI. This limitation is only present when using the traditional bridge configuration.
The VXLAN registration daemon (
vxrd) is not running. Static VXLAN tunnels do not interoperate with LNV or EVPN. If
vxrdis running, stop it with the following command:
cumulus@switch:~ sudo systemctl stop vxrd.service
The following topology is used in this chapter. Each IP address corresponds to the loopback address of the switch.
Configure Static VXLAN Tunnels
To configure static VXLAN tunnels, do the following for each leaf:
- Specify an IP address for the loopback
- Create a VXLAN interface using the loopback address for the local tunnel IP address
- Create the tunnels by configuring the remote IP address to each other leaf switch’s loopback address
To configure leaf01, run the following commands:
cumulus@leaf01:~$ net add loopback lo ip address 10.0.0.11/32 cumulus@leaf01:~$ net add vxlan vni-10 vxlan id 10 cumulus@leaf01:~$ net add vxlan vni-10 vxlan local-tunnelip 10.0.0.11 cumulus@leaf01:~$ net add vxlan vni-10 vxlan remoteip 10.0.0.12 cumulus@leaf01:~$ net add vxlan vni-10 vxlan remoteip 10.0.0.13 cumulus@leaf01:~$ net add vxlan vni-10 vxlan remoteip 10.0.0.14 cumulus@leaf01:~$ net add vxlan vni-10 bridge access 10 cumulus@leaf01:~$ net pending cumulus@leaf01:~$ net commit
These commands create the following configuration in the
# The loopback network interface auto lo iface lo inet loopback address 10.0.0.11/32 # The primary network interface auto eth0 iface eth0 inet dhcp auto swp1 iface swp1 auto swp2 iface swp2 auto bridge iface bridge bridge-ports vni-10 bridge-vids 10 bridge-vlan-aware yes auto vni-10 iface vni-10 bridge-access 10 mstpctl-bpduguard yes mstpctl-portbpdufilter yes vxlan-id 10 vxlan-local-tunnelip 10.0.0.11 vxlan-remoteip 10.0.0.12 vxlan-remoteip 10.0.0.13 vxlan-remoteip 10.0.0.14
Repeat these steps for leaf02, leaf03, and leaf04:
Verify the Configuration
After you configure all the leaf switches, check for replication entries:
cumulus@leaf01:~$ sudo bridge fdb show | grep 00:00:00:00:00:00 00:00:00:00:00:00 dev vni-10 dst 10.0.0.14 self permanent 00:00:00:00:00:00 dev vni-10 dst 10.0.0.12 self permanent 00:00:00:00:00:00 dev vni-10 dst 10.0.0.13 self permanent
Caveats and Errata
Cumulus Linux does not support different
bridge-learning settings for
different VNIs of VXLAN tunnels between 2 VTEPs. For example, the
following configuration in the
/etc/network/interfaces file is not
... auto vni300 iface vni300 vxlan-id 300 vxlan-local-tunnelip 10.252.255.58 vxlan-remoteip 10.250.255.161 mtu 9000 auto vni258 iface vni258 vxlan-id 258 vxlan-local-tunnelip 10.252.255.58 vxlan-remoteip 10.250.255.161 bridge-access 258 bridge-learning off mtu 9000