Restrictions and guidelines: IPv4 over IPv4 tunnel configuration

Follow these guidelines when you configure an IPv4 over IPv4 tunnel:

• The tunnel destination address specified on the local device must be identical with the tunnel source address specified on the tunnel peer device.

• Do not specify the same source and destination addresses for local tunnel interfaces in the same tunnel mode.

• The IPv4 address of the local tunnel interface cannot be on the same subnet as the destination address configured on the tunnel interface.

• To ensure correct packet forwarding, identify whether the destination IPv4 network and the IPv4 address of the local tunnel interface are on the same subnet. If they are not, configure a route reaching the destination IPv4 network through the tunnel interface. You can configure the route by using one of the following methods:

  • Configure a static route, and specify the local tunnel interface as the egress interface or specify the IPv4 address of the peer tunnel interface as the next hop.

  • Enable IS-IS or BGP on both the local and remote tunnel interfaces.

  For more information about route configuration, see Layer 3—IP Routing Configuration Guide.

• The destination address of the route passing the tunnel interface cannot be on the same subnet as the destination address configured on the tunnel interface.