INTERNET-DRAFT Yuko Onoe Norihiro Ishikawa Megumi Kondo Shinji Kobayashi NTT Mobile Communications Network Inc. January 4, 2000 draft-onoe-proxy-server-option-00.txt Proxy Server Configuration Option for PPP IPCP Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 Point-to-Point Protocol(PPP) provides a standard method for transporting multi-protocol datagrams over point-to-point links and is generally used to connect personal computers at home or portable terminals to the Internet using TCP/IPs over phone lines. This document extends the Proxy Server Configuration Option for PPP IPCP (Internet Protocol Control Protocol) and defines negotiation of primary and secondary proxy server addresses for Web browsing applications. With this option, redundant communications for notification of proxy server addresses can be avoided. Moreover, automatic and easy configuration of proxy servers can be realized for Internet beginners. Expires July 4, 2000 Onoe [Page 1] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 Table of Contents 1. Introduction .......................................... 2 2. Proxy Server Configuration Option ..................... 3 2.1 Primary Proxy Server Configuration Option Format .... 3 2.2 Secondary Proxy Server Configuration Option Format .. 4 2.3 Technical overviews ................................. 5 2.4 Procedure of notification of Proxy Server Addresses . 6 2.4.1 Using notifications of Proxy Server Addresses .. 6 2.4.2 Without using notifications of Proxy Server Addresses ...................................... 7 REFRENCES .................................................... 8 SECURITY CONSIDERATIONS ...................................... 8 AUTHOR'S ADDRESS ............................................. 8 1. Introduction These days, PPP(Point-to-Point Protocol)[1] is generally used to connect personal computers at home or portable terminals to the Internet or the office LANs using TCP/IPs over phone lines. The use of PPP is one of the standard methods to transmit various kinds of protocol packets over point-to-point links. It enables users, for example, to connect to the Internet through phone lines, use Web applications over HTTP protocols and refer to Home Pages. In this case, proxy servers are generally located between Web clients and servers and requests for accesses to the servers are relayed and intermediated. At the same time, proxy servers provide some additional functions such as caching and translation of contents to attain communication efficiency and ensure security. The functions of proxy servers can be categorized as follows: (1) firewall functions for filtering out illegal accesses from outside, (2) prefetching, autopiloting and caching by processing requests in advance and (3) filtering of contents, i.e. adding to and changing contents and adjusting or deleting their formats. With the various functions proxy servers have, they play important roles and become indispensable functionality subjects. To use proxy servers over a PPP, the procedure is as follows: (1) LCP(Link Control Protocol)[5] negotiations and authentication of CHAP or PAP are processed. (2) By Configuration-Request/Ack/Nack clients aquire their IP addresses and DNS server addresses[4]. (3) Clients inquire IP addresses of proxy servers to the DNS servers. (4) Clients request connections to proxy servers. Expires July 4, 2000 Onoe [Page 2] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 At this time, if local peers acquire the IP addresses of proxy servers at the time of configuration such as (2), the address inquiry step of (3) becomes unnecessary, and it becomes possible to connect proxy servers after the communications of (2) have been made. Moreover, since configuring the host names of proxy servers is done automatically, beginners can connect to the Internet easily. Furthermore, even if the addresses of proxy servers change, users can continue to use Web applications without being aware of the change. Therefore, we propose to define Proxy Server Configuration Options as Internet Protocol Control Protocol(IPCP)[2]. By using these options, communications become more efficient and utilization of proxy servers becomes easier. 2. Proxy Server Configuration Option In this section, Proxy Server Configuration Option and its usages are described. 2.1. Primary Proxy Server Configuration Option Format Description This Configuration Option defines processes of negotiation of primary proxy servers with remote sides to be used by local sides of PPP links. If local sides specify invalid addresses of proxy servers, remote sides return NAK for this option and respond with valid addresses of proxy servers. By defaults, addresses of primary proxy servers are not specified. Primary Proxy Server Configuration Option for IPCP is defined as follows; 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Primary-Proxy-Server-Address +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Primary-Proxy-Addr(cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Expires July 4, 2000 Onoe [Page 3] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 Type 133 Length 6 Primary-Proxy-Server-Address IP addresses of primary proxy servers used by local sides are specified in 4 octets Primary-Proxy-Server-Address. If 0 is specified to all 4 octets, it indicates that Configure-Nak packets include address information at local sides. Default No address is specified. 2.2. Secondary Proxy Server Configuration Option Format Description This Configuration Option defines processes of negotiation of secondary proxy servers with remote sides to be used by local sides of PPP links. If local sides specify invalid addresses of proxy servers, remote sides return NAK for this option and respond with valid addresses of proxy servers. By defaults, addresses of secondary proxy servers are not specified. Secondary Proxy Server Configuration Option for IPCP is defined as follows; 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Secondary-Proxy-Server-Address +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Secondary-Proxy-Addr(cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Expires July 4, 2000 Onoe [Page 4] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 Type 134 Length 6 Secondary-Proxy-Server-Address IP addresses of secondary proxy servers used by local sides are specified in 4 octets Secondary-Proxy-Server-Address. If 0 is specified to all 4 octets, it indicates that Configure-Nak packets include address information at local sides. Default No address is specified. 2.3. Technical overviews The general procedure of IPCP negotiation is as follows; (1) LCP negotiation and CHAP[6] or PAP authentication is achieved between clients and servers. (2) IPCP Configuration-Request is issued from clients to servers and IP addresses of the clients and DNS servers are returned from servers as Configuration-Nak packets. (3) The clients inquire IP addresses of proxy servers to DNS servers. (4) The DNS servers respond with IP addresses of proxy servers. (5) Clients request connections to proxy servers. In this way, in the existing methods IP addresses of DNS servers and proxy servers are notified twice. PPP configuration takes much time, especially for narrow band and high delay physical links such as communications over phone links. Therefore, we propose to introduce Proxy-Server-Configuration-Option into IPCP. The procedure for using this Proxy-Server-Configuration-Option is as follows; Expires July 4, 2000 Onoe [Page 5] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 (1) LCP negotiation and CHAP or PAP authentication is achieved between clients and servers. (2) IPCP Configuration-Request is issued from the clients to the servers and IP addresses of the clients and proxy servers are returned from the servers as Configuration-Nak packets. (3) Clients request connections to the proxy servers. In this way, on PPP connections over narrow band and high speed physical links such as phone links, redundant communications for notification of server addresses can be avoided and communication overhead for PPP configuration can be reduced. Moreover, proxy server hostname configuration is done automatically and configuring Internet connectivity becomes easy. 2.4. Procedure of notification of Proxy Server Addresses 2.4.1. Using notifications of Proxy Server Addresses As configuration conditions, addresses are not configured at PPP clients and Primary-Proxy-Server-Address and Secondary-Proxy-Server-Address are specified at servers. PPP clients PPP servers | | |<--------------LCP negotiation-------------------->| | | |<--------------CHAP or PAP authentication--------->| | | | Configure-Request(IP[0.0.0.0],PDNS[0.0.0.0], | | PNBNS[0.0.0.0],PPS[0.0.0.0],SDNS[0.0.0.0], | |-------SNBNS[0.0.0.0],SPS[0.0.0.0])--------------->| | | |<-Configure-Reject(PNBNS[0.0.0.0],SNBNS[0.0.0.0])--| | | | Configure-Request(IP[0.0.0.0],PDNS[0.0.0.0], | |-------PPS[0.0.0.0],SDNS[0.0.0.0],SPS[0.0.0.0])--->| | | | Configure-Nak(IP[config-addr],PDNS[config-addr], | | PPS[config-addr],SDNS[config-addr], | |<------SPS[config-addr])---------------------------| | | | Configure-Request(IP[config-addr], | | PDNS[config-addr],PPS[config-addr], | |-------SDNS[config-addr],SPS[config-addr])-------->| | | | Configure-Ack(IP[config-addr],PDNS[config-addr], | | PPS[config-addr],SDNS[config-addr], | |<------SPS[config-addr])---------------------------| Expires July 4, 2000 Onoe [Page 6] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 IP:IP address PDNS:Primary-DNS-Address PNBNS:Primary-NBNS-Address PPS:Primary-Proxy-Server-Address SDNS:Secondary-DNS-Address SNBNS:Secondary-NBNS-Address SPS:Secondary-Proxy-Server-Address config-addr:configured IP address 2.4.2. Without using notification of Proxy Server Addresses As configuration conditions, addresses are not configured at PPP clients and configuration of notifying functions of Primary-Proxy-Server-Address and Secondary-Proxy-Server-Address are set at servers. PPP clients PPP servers | | |<--------------LCP negotiation-------------------->| | | |<--------------CHAP or PAP authentication--------->| | | | Configure-Request(IP[0.0.0.0],PDNS[0.0.0.0], | | PNBNS[0.0.0.0],PPS[0.0.0.0],SDNS[0.0.0.0], | |-------SNBNS[0.0.0.0],SPS[0.0.0.0])--------------->| | | | Configure-Reject(PNBNS[0.0.0.0],PPS[0.0.0.0], | |<------SNBNS[0.0.0.0],SPS[0.0.0.0])----------------| | | | Configure-Request(IP[0.0.0.0],PDNS[0.0.0.0], | |-------SDNS[0.0.0.0])----------------------------->| | | | Configure-Nak(IP[config-addr],PDNS[config-addr], | |<------SDNS[config-addr])--------------------------| | | | Configure-Request(IP[config-addr], | |-------PDNS[config-addr],SDNS[config-addr])------->| | | | Configure-Ack(IP[config-addr],PDNS[config-addr], | |<------SDNS[config-addr])--------------------------| Expires July 4, 2000 Onoe [Page 7] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 References [1] Simpson,W.,``The Point-to-Point Protocol'', RFC1331, May 1992. [2] McGregor,G., ``The PPP Internet Protocol Control Protocol'', RFC1332, Merit, May 1992. [3] Simpson,W., ``The Point-to-Point Protocol(PPP) for the Transmission of Multi-protocol Datagrams over Point-to-Point Links'', STD 51, RFC1661, July 1994. [4] Cobb,S., ``PPP Internet Protocol Control Protocol Extensions or Name Server Addresses'', RFC1877, December 1995. [5] Simpson,W., ``PPP LCP Extensions'', RFC1570, January 1994. [6] Simpson,W., ``PPP Challenge Handshake Authentication Protocol(CHAP)'', RFC1994, August 1996. Security Considerations Security issues are not discussed in this memo. Author's Address Questions about this memo can also be directed to: Yuko Onoe NTT Mobile Communications Network Inc. 3-5, Hikarinooka, Yokosuka, Kanagawa, 239-8536, Japan Phone: +81 468 40 3327 EMail: yuko@mml.yrp.nttdocomo.co.jp Norihiro Ishikawa NTT Mobile Communications Network Inc. 3-5, Hikarinooka, Yokosuka, Kanagawa, 239-8536, Japan Phone: +81 468 40 3819 EMail: ishikawa@mml.yrp.nttdocomo.co.jp Expires July 4, 2000 Onoe [Page 8] INTERNET-DRAFT Proxy Server Configuration Option January 4, 2000 Megumi Kondo NTT Mobile Communications Network Inc. Shin-nikko Bldg., 10-1, Toranomon 2-chome, Minato-ku Tokyo, 105-8436, Japan Phone: +81 3 5563 7204 EMail: megumi@serdev.nttdocomo.co.jp Shinji Kobayashi NTT Mobile Communications Network Inc. Shin-nikko Bldg., 10-1, Toranomon 2-chome, Minato-ku Tokyo, 105-8436, Japan Phone: +81 3 5563 7204 EMail: kobayash@serdev.nttdocomo.co.jp Expires July 4, 2000 Onoe [Page 9]