Vyatta Network OS Documentation

Learn how to install, configure and operate the Vyatta NOS, which helps drive our virtual networking & physical platforms portfolio.

interfaces tunnel <tunx> encapsulation <action>

Sets the encapsulation type for a tunnel interface.

set interfaces tunnel tunx encapsulation { gre | gre-bridge | gre-multipoint | ipip | ipip6 | ip6ip6 | sit }
set interfaces tunnel tunx encapsulation { gre | gre-bridge | gre-multipoint | ipip | ipip6 | ip6ip6 | sit }
show interfaces tunnel tunx encapsulation

GRE is the default encapsulation type.

tunx
The identifier of a tunnel interface. The identifier ranges from tun0 through tunx, where x is a non-negative integer.
gre
Uses GRE to encapsulate transported packets.
gre-bridge
Uses GRE to encapsulate transported packets. This encapsulation type is to be used only for bridging, that is, when the tunnel interface is to be added to a bridge group.
gre-multipoint
Uses multipoint GRE to encapsulate transported packets.
ipip
Uses IP-in-IP to encapsulate transported packets.
ipip6
Uses IP-in-IPv6 to encapsulate transported packets.
ipip
Uses IPv6-in-IPv6 to encapsulate transported packets.
sit
Uses SIT to encapsulate transported packets.

Configuration mode

 interfaces {
     tunnel tunx {
        encapsulation {
           gre      
           gre-bridge
           gre-multipoint
           ipip
           ipip6
           ip6ip6
           sit
         } 
      }

The Generic Routing Encapsulation (GRE) protocol provides a simple-general purpose mechanism for encapsulating packets from a wide variety of network protocols to be forwarded over another protocol. The original packet (the "passenger" packet) can be one of many arbitrary network protocols-for example a multicast packet, an IPv6 packet, or a non-IP LAN protocol such as AppleTalk, Banyen VINES, or Novell IPX. The delivery protocol can be one of a number of routable IP protocols.

A limitations of a regular GRE encapsulated tunnel is that it cannot be added to a bridge group. GRE for Bridging (using the gre-bridge keyword) provides this ability. It should be used only in cases in which tunnel interfaces are to be included in a bridge group. Refer to Ciena Vyatta Network OS Bridging Configuration Guide for further information.

GRE for multipoint (by using the gre-multipoint keyword) is used as part of DMVPN network configurations. Refer to Ciena Vyatta Network OS DMVPN Configuration Guide for further information. The main difference between a standard GRE configuration and a GRE-for-multipoint configuration is that, when configuring GRE for multipoint, you do not specify a remote IP. Everything else remains the same.

The IP-in-IP encapsulation protocol is used to tunnel between networks that have different capabilities or policies. For example, an IP-in-IP tunnel can be used to forward multicast packets across a section of a network (such as an IPsec tunnel) that does not support multicast routing. An IP-in-IP tunnel can also be used to influence the routing of the packet, or to deliver a packet to a mobile device using Mobile IP.

The SIT encapsulation is used to tunnel IPv6 across an IPv4 network.

Use the set form of this command to set the encapsulation type for a tunnel interface.

Use the delete form of this command to delete restore the default encapsulation type, which is GRE, for a tunnel interface.

Use the show form of this command to display the encapsulation type for a tunnel interface.