Configure Tunnel Interfaces

By encapsulating arbitrary packets inside a transport protocol, tunneling provides a private, secure path through an otherwise public network. Tunnels connect discontinuous subnetworks and enable encryption interfaces, virtual private networks (VPNs), and Multiprotocol Label Switching (MPLS). If you have a Tunnel PIC installed in your routing platform, you can configure unicast, multicast, and logical tunnels.

You can configure two types of tunnels for VPNs: one to facilitate routing table lookups and another to facilitate VPN routing and forwarding instance (VRF) table lookups.

For information about encryption interfaces, see Configure Encryption Interfaces and the JUNOS System Basics Configuration Guide. For information about VPNs, see the JUNOS VPNs Configuration Guide. For information about MPLS, see the JUNOS MPLS Applications Configuration Guide.

The JUNOS software supports the following tunnel encapsulations:

• Generic routing encapsulation (GRE)
• IP over IP (IP-IP)
• Virtual Private Network (VPN)
• PIM encapsulation

This chapter discusses the following tunnel interface configuration tasks:

• Configure a Unicast Tunnel
• Configure a Multicast Tunnel
• Configure a Logical Tunnel
• Configure a Tunnel Interface for Routing Table Lookup
• Configure a Tunnel Interface for VRF Table Lookup
• Configure PIM Tunnels
• Configure an IPv6-over-IPv4 Tunnel

For examples of tunnel interface configuration, see the following sections:

• Example: Configure Unicast Tunnels
• Example: Configure a Virtual Loopback Tunnel Interface for VRF Table Lookup
• Example: Configure an IPv6-over-IPv4 Tunnel