Internet Engineering Task Force Alain Durand INTERNET-DRAFT Jim Paugh March 2, 2001 SUN Microsystems, Inc Expires September 1, 2001 MIME TYPE definition for tunnels Status of Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ``work in progress.'' The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract Tunnels are very common in the Internet. They are often used to deploy new technologies such as multicast or IPv6 when the underlying infrastructure is not ready to natively support those new protocols. Virtual Private Network are also often build using IP in IP tunnels. This document describe a MIME type that provide configuration information for tunnels. 1. Introduction Managing IP in IP tunnels can be a complex task and various approaches have been developed to assist network administrators. In the context of IPv6 transition, the tunnel broker model [BROKER] has been developed for that very purpose and highlighted the need for a formal description of IPv6 in IPv4 tunnels. However, such a description can be made more generic and provide information about almost any kind of tunnels. 2. Related work [RADTUN] describe tunnel attributes in RADIUS format. 3. Tunnel management Tools and/or protocols to do the actual tunnel management are out of the scope of this document. 4. MIME type definition In conformance with [MIME], the MIME object to describe tunnels is defined in the IETF tree as a subtype of the "Application" MIME type. The proposed subtype is "tunnel". The tunnel described by this object is a unidirectional tunnel from host SRC to host DST. 4.1 Parameters Mandatory parameters: none Optional parameters: none 4.2 Mandatory MIME headers 4.2.1 Encapsulation type header name: encapsulation-type header type: Integer possible values: Tunnel encapsulation types values are taken from [RADTUN]. 1 Point-to-Point Tunneling Protocol [PPTP] 2 Layer Two Forwarding [L2F] 3 Layer Two Tunneling Protocol [L2TP] 4 Ascend Tunnel Management Protocol [ATMP] 5 Virtual Tunneling Protocol (VTP) 6 IP Authentication Header in the Tunnel-mode (AH) [IPsec] 7 IP-in-IP Encapsulation [IP-IP] 8 Minimal IP-in-IP Encapsulation [MIN-IP] 9 IP Encapsulating Security Payload in the Tunnel-mode [ESP] 10 Generic Route Encapsulation [GRE] 11 Bay Dial Virtual Services (DVS) 12 IP-in-IP Tunneling [IPinIP] 4.2.2 Tunnel inner medium type header name: inner-medium header type: Integer possible values: Tunnel inner medium type values are taken from [NUMBER]. A short exerpt is: 1 IPv4 (IP version 4) 2 IPv6 (IP version 6) 3 NSAP 4 HDLC (8-bit multidrop) 5 BBN 1822 6 802 (includes all 802 media plus Ethernet "canonical format") 7 E.163 (POTS) 8 E.164 (SMDS, Frame Relay, ATM) 9 F.69 (Telex) 10 X.121 (X.25, Frame Relay) 11 IPX 12 Appletalk 13 Decnet IV 14 Banyan Vines 15 E.164 with NSAP format subaddress 4.2.3 Tunnel outer medium type header name: outer-medium header type: Integer possible values: Tunnel outer medium type values are taken from [NUMBER]. A short exerpt is: 1 IPv4 (IP version 4) 2 IPv6 (IP version 6) 3 NSAP 4 HDLC (8-bit multidrop) 5 BBN 1822 6 802 (includes all 802 media plus Ethernet "canonical format") 7 E.163 (POTS) 8 E.164 (SMDS, Frame Relay, ATM) 9 F.69 (Telex) 10 X.121 (X.25, Frame Relay) 11 IPX 12 Appletalk 13 Decnet IV 14 Banyan Vines 15 E.164 with NSAP format subaddress 4.2.4 Inner source address header name: inner-src header type: string possible values: any textual representation of an address enclosed in square brackets. Inner source address is the source address in the inner header of any packet originated from host SRC through the tunnel. 4.2.4 Outer source address header name: outer-src header type: string possible values: any textual representation of an address enclosed in square brackets. Outer source address is the source address in the outer header of any packet originated from host SRC through the tunnel. 4.2.5 Inner destination address header name: inner-dst header type: string possible values: any textual representation of an address enclosed in square brackets. Inner destination address is the destination address in the inner header of any packet originated from host SRC through the tunnel. 4.2.6 Outer destination address header name: outer-dst header type: string possible values: any textual representation of an address enclosed in square brackets. Outer destination address is the destination address in the outer header of any packet originated from host SRC through the tunnel. 4.3 Optional MIME headers 4.3.1 Inner addresses lifetime header name: inner-lifetime header type: Integer possible values: the lifetime in second of the inner pair of addresses, source and destination. A value of zero means infinite lifetime. 4.3.2 Outer addresses lifetime header name: outer-lifetime header type: Integer possible values: the lifetime in second of the outer pair of addresses, source and destination. A value of zero means infinite lifetime. 4.3.3 E-mail contact for SRC header name: src-email header type: string possible values: any valid email address, according to [MAIL]. This is the administrative contact email address for host SRC. The exact semantic of this parameter is beyond the scope of this document. 4.3.4 E-mail contact for DST header name: dst-email header type: string possible values: any valid email address, according to [MAIL]. This is the administrative contact email address for host DST. The exact semantic of this parameter is beyond the scope of this document. 5. IANA registration To: ietf-types@iana.org Subject: Registration of MIME media type application/tunnel MIME media type name: application MIME subtype name: tunnel Required parameters: none Optional parameters: none Encoding considerations: None Required headers: encapsulation-type, inner-medium, outer-medium, inner-src, outer-src, inner-dst, outer-dst Optional headers: inner-lifetime, outer-lifetime, src-email, dst-email Security considerations: The information contained in this MIME type may be used by application to configured tunnel. Inaccurate information can introduce all kind of security hazards, thus it is of the utmost importance that these information are transferred over a secure channel, that their originator is authenticated and that they are guaranteed not to be corrupted. Interoperability considerations: The mandatory parameters are necessary to guarantee interoperability. Published specification: none Applications which use this media type: Tunnel Brokers, tunnel servers, tunnel clients, any database storing tunnel information. Additional information: Magic number(s): none File extension(s): none Macintosh File Type Code(s): none Person & email address to contact for further information: Alain Durand Jim Paugh Alain.Durand@sun.com Jim.Paugh@sun.com Intended usage: COMMON Author/Change controller: Alain.Durand@sun.com, Jim.Paugh@sun.com 6. Security Considerations The information contained in this MIME type may be used by application to configured tunnel. Inaccurate information can introduce all kind of security hazards, thus it is of the utmost importance that these information are transferred over a secure channel, that their originator is authenticated and that they are guaranteed not to be corrupted. The exact procedure/protocols to be used for this purpose is out of the scope of this document. 7. References [BROKER] Durand, A., Fasano, P., Guardini, I., Lento, D., IPv6 Tunnel Broker, RFC3052, February 2001 [MIME] Freed, N., Borenstein, N., "Multipurpose Internet Mail Extensions (MIME) Part four: MIME registration procedure, RFC2048, November 1996. [RADTUN] Zorn, G., Leifer, D., Rubens, A., Shriver, J., Holdrege, M., Goyret, I., RADIUS Attributes for Tunnel Protocol Support, RFC2868, June 2000. [MAIL] Crocker, D., Standard for the format of ARPA Internet text messages, RFC822, August 1982. [NUMBER] Reynolds, J. and J. Postel, "Assigned Numbers", STD 2, RFC 1700, October 1994. [PPTP] Hamzeh, K., Pall, G., Verthein, W., Taarud, J., Little, W. and G. Zorn, "Point-to-Point Tunneling Protocol (PPTP)", RFC 2637, July 1999. [L2F] Valencia, A., Littlewood, M. and T. Kolar, T., "Cisco Layer Two Forwarding (Protocol) 'L2F'", RFC2341, May 1998. [L2TP] Townsley, W., Valencia, A., Rubens, A., Pall, G., Zorn, G. and B. Palter, "Layer Two Tunnelling Protocol (L2TP)", RFC2661, August 1999. [ATMP] Hamzeh, K., "Ascend Tunnel Management Protocol - ATMP", RFC2107, February 1997. [IPsec] Kent, S. and R. Atkinson, "Security Architecture for the Internet Protocol", RFC2401, November 1998. [IP-IP] Perkins, C., "IP Encapsulation within IP", RFC2003, October 1996. [Min-IP] Perkins, C., "Minimal Encapsulation within IP", RFC2004, October 1996. [ESP] Atkinson, R., "IP Encapsulating Security Payload (ESP)", RFC1827, August 1995. [GRE] Hanks, S., Li, T., Farinacci, D. and P. Traina, "Generic Routing Encapsulation (GRE)", RFC 1701, October 1994. [INinIP] Simpson, W., "IP in IP Tunneling", RFC1853, October 1995. 8. Author's addresses Alain Durand SUN Microsystems, Inc 901 San Antonio Road MPK17-202 Palo Alto, CA 94303-4900 USA Mail: Alain.Durand@sun.com Jim Paugh SUN Microsystems, Inc 901 San Antonio Road MPK17-203 Palo Alto, CA 94303-4900 USA Mail: Jim.Paugh@sun.com