Network Working Group R. Droms
Request for Comments: 2242 Bucknell University
Category: Standards Track K. Fong
Novell
November 1997
NetWare/IP Domain Name and Information
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1997). All Rights Reserved.
The Dynamic Host Configuration Protocol (DHCP) [RFC 2131] provides a
framework for passing configuration information to hosts on a TCP/IP
network. DHCP includes options for specific configuration parameters
[RFC 2132]. This document defines options that carry NetWare/IP
domain name and NetWare/IP sub-options to DHCP clients.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY" and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC 2119].
This document uses the following terms:
o "DHCP client"
A DHCP client is an Internet host using DHCP to obtain
configuration parameters such as a network address.
Droms & Fong Standards Track [Page 1]
RFC 2242 NetWare/IP Domain Name and Information November 1997
o "DHCP server"
A DHCP server is an Internet host that returns configuration
parameters to DHCP clients.
This option code is used to convey the NetWare/IP domain name used by
the NetWare/IP product. The NetWare/IP Domain in the option is an NVT
ASCII [RFC 854] string whose length is inferred from the option 'len'
field.
The code for this option is 62, and its maximum length is 255.
Code Len NetWare/IP Domain Name
+-----+-----+------+------+------+-----
| 62 | n | c1 | c2 | c3 | ...
+-----+-----+------+------+------+-----
The 'len' field gives the length of the NetWare/IP Domain Name.
The NetWare/IP option code will be used to convey all the NetWare/IP
related information except for the NetWare/IP domain name.
The code for this option is 63, and its maximum length is 255. A
number of NetWare/IP sub-options will be conveyed using this option
code. The 'len' field for this option gives the length of the option
data, which includes the sub-option code, length and data fields.
Each sub-option contains in sequential order, a one byte sub-option
code, a one byte length, and an optional multiple byte value field.
The sub-option length gives the length of the value field for the
sub-option. The example below illustrates the use of the 'len' and
sub-option length fields in this option.
One and only one of the following four sub-options must be the first
sub-option to be present in option 63 encoding. Each of them is
simply a type length pair with length set to zero.
Sub-options:
NWIP_DOES_NOT_EXIST (code 1)
The responding DHCP server does not have any NetWare/IP
information configured.
Droms & Fong Standards Track [Page 2]
RFC 2242 NetWare/IP Domain Name and Information November 1997
NWIP_EXIST_IN_OPTIONS_AREA (code 2)
All NetWare/IP information is present in the 'options' area of the
DHCP response packet.
NWIP_EXIST_IN_SNAME_FILE (code 3)
All NetWare/IP information is present in the 'sname' and, if
necessary, 'file' fields of the DHCP response packet. If used, the
following DHCP server behavior is required: within the 'options'
area, option 63 is present with its length field set to 2. The
first byte of the value field is set to NWIP_EXIST_IN_SNAME_FILE
tag and the second byte is set to zero. Both option 62 and option
63 will be placed in the area covered by the sname and file
fields. Option 62 is encoded normally. Option 63 is encoded with
its tag, length and value. The value field does not contain any of
the first four sub-options described herein.
NWIP_EXIST_BUT_TOO_BIG (code 4)
Neither 'options' area nor 'sname' field can accommodate the
NetWare/IP information.
If either NWIP_EXIST_IN_OPTIONS_AREA or NWIP_EXIST_IN_SNAME_FILE
sub-options is set, one or more of the following sub-options may be
present.
NSQ_BROADCAST (code 5)
Length is 1 and a value of 1 or 0. If the value is 1, the client
SHOULD perform a NetWare Nearest Server Query to find out its
nearest NetWare/IP server.
PREFERRED_DSS (code 6)
Length is (n * 4) and the value is an array of n IP addresses,
each four bytes in length. The maximum number of addresses is 5
and therefore the maximum length value is 20. The list contains
the addresses of n NetWare Domain SAP/RIP Server (DSS).
NEAREST_NWIP_SERVER (code 7)
Length is (n * 4) and the value is an array of n IP addresses,
each four bytes in length. The maximum number of addresses is 5
and therefore the maximum length value is 20. The list contains
the addresses of n Nearest NetWare/IP servers.
Droms & Fong Standards Track [Page 3]
RFC 2242 NetWare/IP Domain Name and Information November 1997
AUTORETRIES (code 8)
Length is 1 and the value is a one byte integer value indicating
the number of times a NetWare/IP client should attempt to
communicate with a given DSS server at startup.
AUTORETRY_SECS (code 9)
Length is 1 and the value is a one byte integer value indicating
the amount of delay in seconds in between each NetWare/IP client
attempt to communicate with a given DSS server at startup.
NWIP_1_1 (code 10)
Length is 1 and the value is 1 or 0. If the value is 1, the
NetWare/IP client SHOULD support NetWare/IP Version 1.1
compatibility. A NetWare/IP client only needs this compatibility
if it will contact a NetWare/IP version 1.1 server.
PRIMARY_DSS (code 11)
Length of 4, and the value is a single IP address. This field
identifies the Primary Domain SAP/RIP Service server (DSS) for
this NetWare/IP domain. NetWare/IP administration utility uses
this value as Primary DSS server when configuring a secondary DSS
server.
An example of option 63 encoding is provided below.
Code Len NetWare/IP General Info
+-----+-----+----+----+
| 63 | 11 | 2 | 0 |
+-----+-----+----+----+
NWIP_EXIST_IN_OPTIONS_AREA (length 0)
+----+----+----+
| 5 | 1 | 1 |
+----+----+----+
NSQ_BROADCAST_SERVER (length 1)
value is YES
+----+----+------------+
| 7 | 4 | IP address |
+----+----+------------+
NEAREST_NWIP_SERVER (length 4)
value is IP address of server
Droms & Fong Standards Track [Page 4]
RFC 2242 NetWare/IP Domain Name and Information November 1997
[RFC 854] Postel, J. and J. Reynolds, "Telnet Protocol
Specification", RFC 854, May 1983.
[RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[RFC 2131] Droms, R., "Dynamic Host Configuration Protocol", RFC
2131, March 1997.
[RFC 2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.
DHCP currently provides no authentication or security mechanisms.
Potential exposures to attack are discussed in section 7 of the DHCP
protocol specification [RFC 2131].
The NetWare/IP options can be used by unauthorized DHCP servers to
misconfigure NetWare/IP clients with potentially disruptive
information.
Ralph Droms
Computer Science Department
323 Dana Engineering
Bucknell University
Lewisburg, PA 17837
Phone: (717) 524-1145
EMail: droms@bucknell.edu
Kester Fong
Information Access Division
Novell Inc.
SJF-8-265
2010 Fortune Dr,
San Jose, CA95131
Phone:(408)-577-8959
EMail: kfong@novell.com
Droms & Fong Standards Track [Page 5]
RFC 2242 NetWare/IP Domain Name and Information November 1997
Copyright (C) The Internet Society (1997). All Rights Reserved.
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Droms & Fong Standards Track [Page 6]