diff options
| -rw-r--r-- | doc/draft-ietf-dhc-dhcp-dns-02.txt (renamed from doc/draft-ietf-dhc-dhcp-dns-01.txt) | 78 | ||||
| -rw-r--r-- | doc/draft-ietf-dhc-options-1533update-06.txt (renamed from doc/draft-ietf-dhc-options-1533update-04.txt) | 263 |
2 files changed, 171 insertions, 170 deletions
diff --git a/doc/draft-ietf-dhc-dhcp-dns-01.txt b/doc/draft-ietf-dhc-dhcp-dns-02.txt index 273ec09e..b85ed12e 100644 --- a/doc/draft-ietf-dhc-dhcp-dns-01.txt +++ b/doc/draft-ietf-dhc-dhcp-dns-02.txt @@ -2,11 +2,11 @@ Network Working Group Yakov Rekhter Internet Draft Cisco Systems -Expiration Date: January 1997 July 1996 +Expiration Date: April 1997 October 1996 Interaction between DHCP and DNS - draft-ietf-dhc-dhcp-dns-01.txt + draft-ietf-dhc-dhcp-dns-02.txt 1. Status of this Memo @@ -57,7 +57,7 @@ Yakov Rekhter [Page 1] -Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 +Internet Draft draft-ietf-dhc-dhcp-dns-02.txt October 1996 3. Interaction between DHCP and DNS @@ -117,7 +117,7 @@ Yakov Rekhter [Page 2] -Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 +Internet Draft draft-ietf-dhc-dhcp-dns-02.txt October 1996 (2) DHCP server updates both the A and the PTR RRs @@ -135,7 +135,7 @@ Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 the client to convey its FQDN to the server this document defines a new option, called "Client FQDN". - The code for this option is TBD. Its minimum length is 2. + The code for this option is 81. Its minimum length is 4. @@ -177,7 +177,7 @@ Yakov Rekhter [Page 3] -Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 +Internet Draft draft-ietf-dhc-dhcp-dns-02.txt October 1996 The update shall be originated following the procedures described in @@ -191,6 +191,9 @@ Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 option shall be set to 1. + A client should set the RCODE1 and RCODE2 fields in the Client FQDN + option to 0 when sending the option. + Whether the client wants to be responsible for updating the FQDN to IP address mapping, or whether the client wants to delegate this responsibility to a server is a local to the client matter. The @@ -225,9 +228,6 @@ Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 option). The server shall originate the update before the server sends the DHCPACK message to the client. The update shall be originated following the procedures described in [DynDNS]. The RCODE - from the update [DynDNS] should be carried to the client in the - RCODE2 field of the Client FQDN option in the DHCPACK message. - @@ -237,12 +237,20 @@ Yakov Rekhter [Page 4] -Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 +Internet Draft draft-ietf-dhc-dhcp-dns-02.txt October 1996 + from the update [DynDNS] should be carried to the client in the + RCODE2 field of the Client FQDN option in the DHCPACK message. + When a server receives a DHCPREQUEST message from a client, and the message contains the Client FQDN option, the server shall ignore the - value carried in the RCODE field of the option. + value carried in the RCODE1 and RCODE2 fields of the option. + + When a DHCP server sends the Client FQDN option to a client in the + DHCPACK message, the server should copy the Flags and the Domain Name + fields from the Client FQDN option that the client sent to the server + in the DHCPREQUEST message. If a server originates updates for both the A and PTR RRs, then the @@ -271,23 +279,15 @@ Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 -6. Security Considerations - Security issues are not discussed in this document. -7. References - [RFC1034] P. Mockapetris, "Domain names - concepts and facilities", - RFC1034, 11/01/1987 - [RFC1035] P. Mockapetris, "Domain names - implementation and - specification", RFC1035, 11/01/1987 - [RFC1541] R. Droms, "Dynamic Host Configuration Protocol", RFC1541, - 10/27/1993 - [RFC1594] A. Marine, J. Reynolds, G. Malkin, "FYI on Questions and + + @@ -297,9 +297,26 @@ Yakov Rekhter [Page 5] -Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 +Internet Draft draft-ietf-dhc-dhcp-dns-02.txt October 1996 + + +6. Security Considerations + + Security issues are not discussed in this document. + + +7. References + + [RFC1034] P. Mockapetris, "Domain names - concepts and facilities", + RFC1034, 11/01/1987 + + [RFC1035] P. Mockapetris, "Domain names - implementation and + specification", RFC1035, 11/01/1987 + [RFC1541] R. Droms, "Dynamic Host Configuration Protocol", RFC1541, + 10/27/1993 + [RFC1594] A. Marine, J. Reynolds, G. Malkin, "FYI on Questions and Answer Answers to Commonly asked ``New Internet User'' Questions", RFC1594, 03/11/1994 @@ -334,23 +351,6 @@ Internet Draft draft-ietf-dhc-dhcp-dns-01.txt July 1996 - - - - - - - - - - - - - - - - - Yakov Rekhter [Page 6] diff --git a/doc/draft-ietf-dhc-options-1533update-04.txt b/doc/draft-ietf-dhc-options-1533update-06.txt index a57e691c..f62107ae 100644 --- a/doc/draft-ietf-dhc-options-1533update-04.txt +++ b/doc/draft-ietf-dhc-options-1533update-06.txt @@ -1,14 +1,15 @@ + Network Working Group S. Alexander INTERNET DRAFT Silicon Graphics, Inc. -Obsoletes: draft-ietf-dhc-options-1533update-03.txt R. Droms +Obsoletes: draft-ietf-dhc-options-1533update-05.txt R. Droms Bucknell University - May 1996 - Expires November 1996 + December 1996 + Expires June 1997 DHCP Options and BOOTP Vendor Extensions - <draft-ietf-dhc-options-1533update-04.txt> + <draft-ietf-dhc-options-1533update-06.txt> Status of this memo @@ -39,8 +40,8 @@ Abstract This document specifies the current set of DHCP options. Future options will be specified in separate RFCs. The current list of - valid options is also available in ftp://ftp.isi.edu/in- - notes/iana/assignments [22]. + valid options is also available in + ftp://ftp.isi.edu/in-notes/iana/assignments [22]. All of the vendor information extensions defined in RFC 1497 [2] may be used as DHCP options. The definitions given in RFC 1497 are @@ -52,7 +53,7 @@ Abstract Alexander & Droms [Page 1] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 extensions. @@ -68,11 +69,11 @@ Table of Contents 7. TCP Parameters ............................................ 20 8. Application and Service Parameters ........................ 21 9. DHCP Extensions ........................................... 29 - 10. Defining new extensions ................................... 36 - 11. Acknowledgements .......................................... 36 - 12. References ................................................ 37 - 13. Security Considerations ................................... 38 - 14. Authors' Addresses ........................................ 38 + 10. Defining new extensions ................................... 35 + 11. Acknowledgements .......................................... 35 + 12. References ................................................ 36 + 13. Security Considerations ................................... 37 + 14. Authors' Addresses ........................................ 37 1. Introduction @@ -108,18 +109,17 @@ Table of Contents Alexander & Droms [Page 2] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 appears in RFC1533. The classing mechanism has been extended to - include vendor classes and user classes as described in section 8.4, - 9.13 and 9.15. The new procedure for defining new DHCP/BOOTP options - in described in section 10. Several new options, including NIS+ - domain and servers, Mobile IP home agent, SMTP server, TFTP server - and Bootfile server, have been added. Text giving definitions used - throughout the document has been added in section 1.1. Text - emphasizing the need for uniqueness of client-identifiers has been - added to section 9.14. + include vendor classes as described in section 8.4 and 9.13. The new + procedure for defining new DHCP/BOOTP options in described in section + 10. Several new options, including NIS+ domain and servers, Mobile + IP home agent, SMTP server, TFTP server and Bootfile server, have + been added. Text giving definitions used throughout the document has + been added in section 1.1. Text emphasizing the need for uniqueness + of client-identifiers has been added to section 9.14. 1.1 Requirements @@ -162,12 +162,13 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 + Alexander & Droms [Page 3] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 -1. Terminology +1.2 Terminology This document uses the following terms: @@ -220,7 +221,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 4] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 dotted decimal 99.130.83.99 (or hexadecimal number 63.82.53.63) in @@ -276,7 +277,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 5] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 3.2. End Option @@ -310,8 +311,11 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 The time offset field specifies the offset of the client's subnet in seconds from Coordinated Universal Time (UTC). The offset is - expressed as a two's complement 32-bit integer. The code for the time - offset option is 2, and its length is 4 octets. + expressed as a two's complement 32-bit integer. A positive offset + indicates a location east of the zero meridian and a negative offset + indicates a location west of the zero meridian. + + The code for the time offset option is 2, and its length is 4 octets. Code Len Time Offset +-----+-----+-----+-----+-----+-----+ @@ -327,12 +331,9 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 - - - Alexander & Droms [Page 6] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 3.5. Router Option @@ -388,7 +389,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 7] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 3.8. Domain Name Server Option @@ -444,7 +445,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 8] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 3.11. LPR Server Option @@ -500,7 +501,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 9] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 3.14. Host Name Option @@ -556,7 +557,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 10] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 3.17. Domain Name @@ -612,7 +613,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 11] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 3.20. Extensions Path @@ -668,7 +669,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 12] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 4.2. Non-Local Source Routing Enable/Disable Option @@ -724,7 +725,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 13] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 4.4. Maximum Datagram Reassembly Size @@ -780,7 +781,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 14] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 4.7. Path MTU Plateau Table Option @@ -836,7 +837,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 15] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 5.2. All Subnets are Local Option @@ -892,7 +893,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 16] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 5.5. Mask Supplier Option @@ -948,7 +949,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 17] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 5.8. Static Route Option @@ -1004,7 +1005,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 18] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 6. Link Layer Parameters per Interface @@ -1060,7 +1061,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 19] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 7. TCP Parameters @@ -1116,7 +1117,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 20] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 8. Application and Service Parameters @@ -1172,7 +1173,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 21] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 8.4. Vendor Specific Information @@ -1228,7 +1229,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 22] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 8.5. NetBIOS over TCP/IP Name Server Option @@ -1284,7 +1285,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 23] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 The code for this option is 46. The length of this option is always @@ -1340,7 +1341,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 24] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 8.10. X Window System Display Manager Option @@ -1396,7 +1397,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 25] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 8.13. Mobile IP Home Agent option @@ -1452,7 +1453,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 26] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 8.16. Network News Transport Protocol (NNTP) Server Option @@ -1508,7 +1509,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 27] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 8.19. Default Internet Relay Chat (IRC) Server Option @@ -1564,7 +1565,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 28] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 9. DHCP Extensions @@ -1620,7 +1621,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 29] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 The code for this option is 52, and its length is 1. Legal values @@ -1676,7 +1677,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 30] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 9.6. DHCP Message Type @@ -1706,9 +1707,11 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 This option is used in DHCPOFFER and DHCPREQUEST messages, and may optionally be included in the DHCPACK and DHCPNAK messages. DHCP servers include this option in the DHCPOFFER in order to allow the - client to distinguish between lease offers. DHCP clients indicate - which of several lease offers is being accepted by including this - option in a DHCPREQUEST message. + client to distinguish between lease offers. DHCP clients use the + contents of the 'server identifier' field as the destination address + for any DHCP messages unicast to the DHCP server. DHCP clients also + indicate which of several lease offers is being accepted by including + this option in a DHCPREQUEST message. The identifier is the IP address of the selected server. @@ -1728,11 +1731,9 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 - - Alexander & Droms [Page 31] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 9.8. Parameter Request List @@ -1788,7 +1789,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 32] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 9.10. Maximum DHCP Message Size @@ -1844,7 +1845,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 33] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 9.13. Vendor class identifier @@ -1900,7 +1901,7 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Alexander & Droms [Page 34] -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 The code for this option is 61, and its minimum length is 2. @@ -1910,54 +1911,6 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 | 61 | n | t1 | i1 | i2 | ... +-----+-----+-----+-----+-----+--- -9.15. User Class Information - - This option is used by a DHCP client to optionally identify the type - or category of user or applications it represents. The information - contained in this option is an NVT ASCII text object that represents - the user class of which the client is a member. - - DHCP administrators may define specific user class identifiers to - convey information about a client's software configuration or about - its user's preferences. For example, an identifier may specify that - a particular DHCP client is a member of the class "accounting - auditors", which have special service needs such as a particular - database server. - - Servers not equipped to interpret any of user classes specified by a - client MUST ignore it (although it may be reported). Otherwise, - servers SHOULD respond with the set of options corresponding to the - user class specified by the client. Further, if the server responds, - it MUST return this option to the client. - - Clients which do not receive information for the user class requested - SHOULD make an attempt to operate without it, although they may do so - (and may announce they are doing so) in a degraded mode. - - The code for this option is 77. The minimum length for this option - is two. - - Code Len text1 - +-----+-----+-----+-----+----- - | 77 | N | c1 | c2 | ... - +-----+-----+-----+-----+----- - - - - - - - - - - - - - -Alexander & Droms [Page 35] - -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 - 10. Defining new extensions @@ -1998,21 +1951,26 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 11. Acknowledgements - The authors would like to thank Philip Almquist for his feedback - on this document. The comments of the DHCP Working Group are - also gratefully acknowledged. In particular, Mike Carney and - Jon Dreyer from SunSelect suggested the current format of the - Vendor-specific Information option. + The author thanks the many (and too numerous to mention!) + - RFC 1497 is based on earlier work by Philip Prindeville, with - help from Drew Perkins, Bill Croft, and Steve Deering. +Alexander & Droms [Page 35] + +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 + members of the DHC WG for their tireless and ongoing efforts in + the development of DHCP and this document. -Alexander & Droms [Page 36] - -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 + + The efforts of J Allard, Mike Carney, Dave Lapp, Fred Lien and + John Mendonca in organizing DHCP interoperability testing + sessions are gratefully acknowledged. + + The development of this document was supported in part by grants + from the Corporation for National Research Initiatives (CNRI), + Bucknell University and Sun Microsystems. 12. References @@ -2050,6 +2008,14 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 [10] McLaughlin, L., "Line Printer Daemon Protocol", RFC 1179, The Wollongong Group, August 1990. + + + +Alexander & Droms [Page 36] + +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 + + [11] Accetta, M., "Resource Location Protocol", RFC 887, CMU, December 1983. @@ -2063,14 +2029,6 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 U. C. Berkeley, April 1984. [15] Hornig, C., "Standard for the Transmission of IP Datagrams over - - - -Alexander & Droms [Page 37] - -DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 - - Ethernet Networks", RFC 894, Symbolics, April 1984. [16] Postel, J. and J. Reynolds, "Standard for the Transmission of @@ -2106,6 +2064,14 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 Steve Alexander Silicon Graphics, Inc. 2011 N. Shoreline Boulevard + + + +Alexander & Droms [Page 37] + +DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 + + Mailstop 510 Mountain View, CA 94043-1389 @@ -2122,5 +2088,40 @@ DRAFT DHCP Options and BOOTP Vendor Extensions May 1996 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Alexander & Droms [Page 38] - + |