IP over IP (IPIP) Tunnel Interface

Document revision 29-Nov-2002
This document applies to the MikroTik RouterOS V2.6

Overview

The IPIP tunneling implementation on the MikroTik RouterOS is RFC 2003 compliant. IPIP tunnel is a simple protocol that encapsulates IP packets in IP to make a tunnel between two routers. The IPIP tunnel interface appears as an interface under the interface list. Many routers, including Cisco and Linux based, support this protocol. This protocol makes multiple network schemes possible.

Network setups with IPIP interfaces:

Contents of the Manual

The following topics are covered in this manual:

Installation

The IP over IP tunnel feature is included in the 'system' package. No installation is needed for this feature.

Hardware Resource Usage

This protocol uses a minimum of resources.

IPIP Interface and Protocol Description

An IPIP interface should be configured on two routers that have the possibility for an IP level connection and are RFC 2003 compliant. The IPIP tunnel may run over any connection that transports IP. Each IPIP tunnel interface can connect with one remote router that has a corresponding interface configured. An unlimited number of IPIP tunnels may be added to the router. For more details on IPIP tunnels, see RFC 2003.

IPIP Setup

IP over IP Interface management can be accessed under the /interface ipip submenu.

You can add an IPIP tunnel interface using the /interface ipip add command: 

[admin@MikroTik] interface ipip> add name test_IPIP mtu 1480 local-address 10.0.0.204 \
\... remote-address 10.0.0.171
[admin@MikroTik] interface ipip> print
Flags: X - disabled, R - running
  #    NAME                 MTU   LOCAL-ADDRESS   REMOTE-ADDRESS
  0 X  test_IPIP            1480  10.0.0.204      10.0.0.171
[admin@MikroTik] interface ipip> enable 0
[admin@MikroTik] interface ipip> print
Flags: X - disabled, R - running
  #    NAME                 MTU   LOCAL-ADDRESS   REMOTE-ADDRESS
  0 R  test_IPIP            1480  10.0.0.204      10.0.0.171
[admin@MikroTik] interface ipip>

Descriptions of settings:

name - Interface name for reference
mtu - Maximum Transmit Unit. Should be set to 1480 bytes to avoid fragmentation of packets. May be set to 1500bytes if mtu path discovery is not working properly on links.
local-address - Local address on router which sends IPIP traffic to the remote side.
remote-address - The IP address of the other side of the IPIP tunnel - may be any RFC 2003 compliant router.

Use /ip address add command to assign an IP address to the IPIP interface.

There is no authentication or 'state' for this interface. The bandwidth usage of the interface may be monitored with the monitor feature from the interface menu.

The router at the other end should have the remote-address set to [MikroTik].

IPIP CISCO Example Our IPIP implementation has been tested with Cisco 1005. Sample of the Cisco 1005 configuration: 

interface Tunnel0
 ip address 10.3.0.1 255.255.255.0
 tunnel source 10.0.0.171
 tunnel destination 10.0.0.204
 tunnel mode ipip

Additional Resources

Links for IPIP documentation:

http://www.ietf.org/rfc/rfc1853.txt?number=1853
http://www.ietf.org/rfc/rfc2003.txt?number=2003
http://www.ietf.org/rfc/rfc1241.txt?number=1241

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