Creating Tunnels

You can create tunnels to encapsulate protocols on the network. You can create tunnels for IP-in-IP, VXLAN, and NVGRE network traffic. However, tunnels are supported on the local scope only and do not use any discovery mechanism.

IP-in-IP protocol encapsulates an IP header with an outer IP header for tunneling. The outer IP header source and destination identifies the endpoints of a tunnel. The inner IP header source and destination identify the original sender and recipient of the datagram.

In addition to the IP header and the VXLAN header, the VTEP also inserts a UDP header. During ECMP, the switch includes this UDP header to perform the hash function. The VTEP calculates the source port by performing the hash of the inner Ethernet frame's header. The Destination UDP port is the VXLAN port.

The outer IP header contains the Source IP address of the VTEP performing the encapsulation. The destination IP address is the remote VTEP IP address or the IP Multicast group address.

Network Virtualization using Generic Routing Encapsulation (NVGRE) uses GRE to tunnel Layer 2 packets over Layer 3 networks. NVGRE is similar to VXLAN but it doesn’t rely on IP multicast for address learning.

To create a tunnel for IP-in-IP traffic, local IP address, and the router, tunnel-network, use the following syntax:

CLI (network-admin@switch) > tunnel-create scope local name ipinip type ip-in-ip local-ip router-if vrouter-hw-if eth0.0

To remove a tunnel, use the tunnel-delete command.

To modify a tunnel, use the tunnel-modify command.

Logging Changes to Tunnel States

This feature enables you to log tunnel state changes so you can view tunnel state historical data for debugging purposes. The following state changes are logged in tunnel history:

Creating tunnels.

Deleting tunnels.

Tunnel hardware state changes including:

  • Virtual Router ID (VRID) associated with the tunnel vrouter
  • the router interface associated with the tunnel local-ip
  • the tunnel next hop add or remove
  • tunnel next hop egress ports
  • Equal-Cost Multi-Path routing (ECMP) group updates

Tunnel History Commands

To update tunnel history settings, use the tunnel-history-settings-modify command:

CLI (network-admin@switch) > tunnel-history-settings-modify enable|disable disk-space disk-space-number log-file-count 1..20

To display tunnel history settings, use the tunnel-history-settings-show command:

CLI (network-admin@switch) > tunnel-history-settings-show

To display historical tunnel state history, us the tunnel-history-show command:

CLI (network-admin@switch) > tunnel-history-show