分享
 
 
 

RFC2097 - The PPP NetBIOS Frames Control Protocol (NBFCP)

王朝other·作者佚名  2008-05-31
窄屏简体版  字體: |||超大  

Network Working Group G. Pall

Request for Comments: 2097 Microsoft Corp.

Category: Standards Track January 1997

The PPP NetBIOS Frames Control Protocol (NBFCP)

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.

Abstract

The Point-to-Point Protocol (PPP) [1] provides a standard method for

transporting multi-protocol datagrams over point-to-point links. PPP

defines an extensible Link Control Protocol, and proposes a family of

Network Control Protocols for establishing and configuring different

network-layer protocols.

The NBF protocol [3] was originally called the NetBEUI protocol. This

document defines the Network Control Protocol for establishing and

configuring the NBF protocol over PPP.

The NBFCP protocol is only applicable for an end system to connect to

a peer system or the LAN that peer system is connected to. It is not

applicable for connecting two LANs together due to NetBIOS name

limitations and NetBIOS name defense mechanisms.

Table of Contents

1. IntrodUCtion .......................................... 2

1.1 Specification of Requirements ................... 2

1.2 Terminology ..................................... 3

2. A PPP Network Control Protocol for NBF ................ 3

2.1 Sending NBF Datagrams ........................... 4

2.2 Bridging NBF Datagrams........................... 5

2.3 NetBIOS Name Defense............................. 5

3. NBFCP Configuration Options ........................... 6

3.1 Name-Projection.................................. 6

3.2 Peer-Information................................. 8

3.3 Multicast-Filtering.............................. 10

3.4 IEEE-MAC-Address-Required........................ 11

SECURITY CONSIDERATIONS ...................................... 12

REFERENCES ................................................... 12

ACKNOWLEDGEMENTS ............................................. 13

CHAIR'S ADDRESS .............................................. 13

AUTHOR'S ADDRESS ............................................. 13

1. Introduction

PPP has three main components:

1. A method for encapsulating multi-protocol datagrams.

2. A Link Control Protocol (LCP) for establishing, configuring,

and testing the data-link connection.

3. A family of Network Control Protocols for establishing and

configuring different network-layer protocols.

In order to establish communications over a point-to-point link, each

end of the PPP link must first send LCP packets to configure and test

the data link. After the link has been established and optional

facilities have been negotiated as needed by the LCP, PPP must send

NBFCP packets to choose and configure the NBF network-layer protocol.

Once NBFCP has reached the Opened state, NBF datagrams can be sent

over the link.

The link will remain configured for communications until eXPlicit LCP

or NBFCP packets close the link down, or until some external event

occurs (an inactivity timer expires or network administrator

intervention).

1.1. Specification of Requirements

In this document, several Words are used to signify the requirements

of the specification. These words are often capitalized.

MUST This word, or the adjective "required", means that the

definition is an absolute requirement of the specification.

MUST NOT This phrase means that the definition is an absolute

prohibition of the specification.

SHOULD This word, or the adjective "recommended", means that there

may exist valid reasons in particular circumstances to

ignore this item, but the full implications should be

understood and carefully weighed before choosing a

different course.

MAY This word, or the adjective "optional", means that this

item is one of an allowed set of alternatives. An

implementation which does not include this option MUST be

prepared to interoperate with another implementation which

does include the option.

1.2. Terminology

This document frequently uses the following terms:

peer The other end of the point-to-point link.

silently discard

This means the implementation discards the packet without

further processing. The implementation SHOULD provide the

capability of logging the error, including the contents of

the silently discarded packet, and SHOULD record the event

in a statistics counter.

end-system

A user's machine. It only sends packets to servers and

other end-systems. It doesn't pass any packets through

itself.

router Allows packets to pass through, usually from one ethernet

segment to another. Sometimes these are called

"intermediate-systems".

bridge Allows packets to pass through with the data field

unmodified. Usually from one ethernet segment to another

or from one ethernet segment to a token-ring segment.

gateway Allows packets to be sent from one network protocol to

the same or different network protocol. For example,

NetBIOS packets from an NBF network to a TCP/IP network

which has implemented RFC1001 and RFC1002.

local Access only server A server which does not pass any packets

through itself to other servers.

2. A PPP Network Control Protocol for NBF

The NBF Control Protocol (NBFCP) is responsible for configuring,

enabling, and disabling the NBF protocol modules on both ends of the

point-to-point link. NBFCP uses the same packet exchange mechanism

as the Link Control Protocol. NBFCP packets MUST NOT be exchanged

until PPP has reached the Network-Layer Protocol phase. NBFCP

packets received before this phase is reached should be silently

discarded.

The NBF Control Protocol is exactly the same as the Link Control

Protocol [1] with the following exceptions:

Frame Modifications

The packet may utilize any modifications to the basic frame format

which have been negotiated during the Link Establishment phase.

Data Link Layer Protocol Field

Exactly one NBFCP packet is encapsulated in the Information field

of a PPP Data Link Layer frame where the Protocol field indicates

type hex 803f (NBF Control Protocol).

Code field

Only Codes 1 through 7 (Configure-Request, Configure-Ack,

Configure-Nak, Configure-Reject, Terminate-Request, Terminate-Ack

and Code-Reject) are used. Other Codes should be treated as

unrecognized and should result in Code-Rejects.

Timeouts

NBFCP packets MUST NOT be exchanged until PPP has reached the

Network-Layer Protocol phase. An implementation should be

prepared to wait for Authentication and Link Quality Determination

to finish before timing out waiting for a Configure-Ack or other

response. It is suggested that an implementation give up only

after user intervention or a configurable amount of time. Also,

because NetBIOS name defense takes time (typically a minimum of

3 seconds if names are added in parallel), it is suggested that

if Name-Projection is negotiated, the timeouts are increased to 10

seconds.

Configuration Option Types

NBFCP has a distinct set of Configuration Options.

2.1. Sending NBF Datagrams

Before any NBF packets may be communicated, PPP must reach the

Network-Layer Protocol phase, and the NBF Control Protocol must reach

the Opened state.

Unless otherwise negotiated, exactly one NBF packet is encapsulated

in the Information field of a PPP Data Link Layer frame where the

Protocol field indicates type hex 003f (NBF datagram).

Since NBF datagrams for PPP do not contain a datagram length field,

the encapsulated NBF packet MUST NOT contain any extra octet padding

except when Self-Defining-Padding is negotiated.

The maximum length of an NBF datagram transmitted over a PPP link is

the same as the maximum length of the Information field of a PPP data

link layer frame. Since there is no standard method for fragmenting

and reassembling NBF datagrams, PPP links supporting NBF MUST allow

at least 576 octets in the information field of a data link layer

frame. It is recommended that an implementation allow 1500 octets in

the information field unless the IEEE-MAC-Address-Required boolean

option is negotiated (see below).

2.2 Bridging NBF Datagrams

There exist at least four different MAC header implementations for

NBF packets: 802.3 Ethernet, 802.5 Token-Ring, DIX Ethernet, and

FDDI. Because NBF is not a routable protocol, some PPP

implementations may require IEEE MAC addresses to properly route or

bridge NBF packets. Some PPP implementations may require the entire

MAC media header in order to properly route or bridge NBF packets.

Other smarter implementations may only require the IEEE MAC addreses,

and still other implementations (such as NetBIOS gateways) may not

require any MAC address fields. NBFCP implementations which require

IEEE Addresses should negotiate the NBFCP IEEE-MAC-Address-Required

boolean configuartion option so that the MAC header can be provided

in the NBF packet.

If IEEE-MAC-Address-Required boolean configuration option is

negotiated, all NBF datagrams MUST be sent with the specified 12

octet IEEE MAC address header. Since negotiation of this option

occurs after the LCP phase, NBF packets MAY exceed the negotiated PPP

MRU size. A PPP implementation which negotiates this option MUST

allow reception of PPP NBF packets 12 octets larger than the

negotiated MRU size.

2.3 NetBIOS Name Defense

In order to guarantee uniqueness of NetBIOS Names on the network,

NBFCP requires that end-system implementations MUST negotiate the

Name-Projection configuration option.

3. NBFCP Configuration Options

NBFCP Configuration Options allow modifications to the standard

characteristics of the network-layer protocol to be negotiated. If a

Configuration Option is not included in a Configure-Request packet,

the default value for that Configuration Option is assumed.

NBFCP uses the same Configuration Option format defined for LCP [1],

with a separate set of Options.

Up-to-date values of the NBFCP Option Type field are specified in the

most recent "Assigned Numbers" RFC[2]. Current values are assigned

as follows:

1 Name-Projection

2 Peer-Information

3 Multicast-Filtering

4 IEEE-MAC-Address-Required

3.1. Name-Projection

Description

This Configuration Option provides a method for the peer to

provide the NetBIOS names registered on its network. The sender

of the Configure-Request states which NetBIOS names should be

added by the remote peer. More than one Name-Projection option

MAY appear in a single Configure-Request.

Implementations which do not attempt to add any NetBIOS names MUST

Configure-Reject the Name-Projection Configuration Option.

If the Name-Projection Configuration Option is not offered by the

remote peer, but is required by the local peer, the local peer

should Configure-Nak the request and indicate that it wishes the

remote peer to add zero NetBIOS names because it is the only known

acceptable value. The remote peer may then terminate NBFCP,

attempt to add zero NetBIOS names, or attempt add one or more

NetBIOS names.

When the receiving peer cannot add all the requested names, it

MUST Configure-Nak with the complete list of names requested.

Those names which could be added should have the Added field set

to zero. Those names which could not be added should have the

Added field set to an appropriate non-zero return code. The

sender of this Configuration Option SHOULD then resend the

Configure-Request with the successfully added names.

The implementation may choose to fail configuration if the

complete list of NetBIOS names is not accepted. By failing, the

implementation should terminate NBFCP by sending a Terminate-

Request packet.

Because adding NetBIOS names can take time (usually 3 seconds) and

because PPP may default the restart timer to 3 seconds, the

restart timer SHOULD default to 10 seconds when configuring

NetBIOS names.

A summary of the Name-Projection Configuration Option format is shown

below. The fields are transmitted from left to right.

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 1st NetBIOS-Name

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

1st NetBIOS-Name (cont.)

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

1st NetBIOS-Name (cont.)

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

1st NetBIOS-Name (cont.)

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

1st NetBIOS-Name (cont.) Added 2nd NetBIOS Name...

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type

1

Length

2 + (Number of NetBIOS names * 17)

NetBIOS-Names

This group of zero or more sixteen octet NetBIOS-Name fields

contains a list of all the NetBIOS names the peer wishes to add to

the remote network if the packet is Configure-Request. If the

packet is Configure-Reject, the peer does not support this

configuration option and it can be assumed that no NetBIOS names

were added.

Because the length field is only one octet, only 14 NetBIOS names

can be added per Name-Projection option. If more than 14 NetBIOS

names should be added, then more than one Name-Projection option

packet will have to be sent in the Configure-Request packet.

Added

This is a one octet field which plays a dual role. The Added

field in the Name-Projection Request packet contains the type of

NetBIOS name added. A summary of name types is listed below.

01 Unique Name.

02 Group Name.

If the packet is a Configure-Reject the Added field should contain

the NetBIOS return code for the NetBIOS Add Name or NetBIOS Add

Group Name command as defined in the NetBIOS 3.0 specification =

[3].

A summary of common result codes is listed below in type hex.

00 Name successfully added.

0D Duplicate name in local name table.

0E Name table full.

15 Name not found or cannot specify "*" or null.

16 Name in use on remote NetBIOS.

19 Name conflict detected.

30 Name defined by another environment.

35 Required system resources exhausted.

3.2. Peer-Information

Description

This Configuration Option provides a way for the peer to

communicate NetBIOS pertinent configuration information. Although

negotiation of this option is not mandatory, it is suggested.

A summary of the Peer-Information Option format is shown below. The

fields are transmitted from left to right.

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 Peer-class

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Peer-version (major) Peer-version(minor)

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Peer-name ....

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type

2

Length

>=3D8

If the length is 8, there is no Peer-name. If the length is

greater than 8, the Peer-name's length is Length - 8.

Peer-class

The Peer-class field is one octet. It identifies the sender's

implementation type.

Initial values are assigned as follows:

Value Class

1 Reserved for legacy implementations.

2 PPP NetBIOS Gateway Server.

3 Reserved for legacy implementations.

4 PPP Local Access Only Server.

5 Reserved for legacy implementations.

6 PPP NBF Bridge.

7 Reserved for legacy implementations.

8 PPP End-System.

Peer-version

The Peer-version field is four octets and indicates the version of

the communication peer providing one side of the PPP connection.

The first two octets are the major version number and the last two

octets are the minor version number. The major and minor version

represent a 16 bit unsigned number sent with the most significant

octet first.

Peer-name

The name of the peer. A suggested name is the NetBIOS workstation

name of the peer. If the length field is 8, no peer name is

provided. The peer-name may not be greater than 32 octets in

length.

3.3. Multicast-Filtering

Description

This Configuration Option provides a way to negotiate the use of

the Multicast-Forward-Period and the Multicast-Priority. This

Configuration Option provides a way to negotiate how to handle

mulicast packets. It allows the sender of the Configure-Request

to state the current handling of multicast packets. The peer can

request parameters by NAKing the option, and returning valid

Multicast-Filtering parameters.

If negotiation about the remote Multicast-Filtering is required,

and the peer did not provide the option in its Configure-Request,

the option SHOULD be appended to a Configure-Nak.

Controlling the multicast rate is important because some NetBIOS

applications use multicasts to communicate and withholding

multicasts may prevent these applications from working. It is

also true that other NetBIOS applications do not need to receive

any multicast packets and therefore it is best to quench the rate

at which the peer will send multicast packets.

By default, the peer is pre-configured to an administrator

assigned Multicast-Forward-Period and Priority. A Multicast-

Forward-Period specified as hex type FFFF in a Configure-Request

is interpreted as requesting the receiving peer to specify a value

in its Configure-Nak. A Multicast-Forward-Period value specified

as hex type FFFF in a Configure-Nak is interpreted as agreement

that no value exists. A Multicast-Forward-Period of zero indicates

that all multicast packets SHOULD be forwarded.

Peers that rely on all multicast packets being forwarded SHOULD

request a Multicast-Forward-Period of zero and a Multicast-

Priority of one by NAKing the Configure-Request option and

appending the proper parameters to a Configure-Nak.

A summary of the Multicast-Filtering Configuration Option format is

shown below. The fields are transmitted from left to right.

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 Multicast-Forward-Period

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Priority

+-+-+-+-+-+-+-+-+

Type

3

Length

5

Multicast-Forward-Period

The Multicast-Forward-Period field is two octets and indicates

the maximum period in seconds at which multicast packets can

be sent. The maximum value for this field is 60 (one minute).

A value of zero indicates that there is no maximum period at

which multicast packets can be sent. A value of hex type FFFF

indicates that the Multicast-Forward-Period is unknown. A value

of five indicates that multicast packets will not be sent at a

rate more frequent than once every five seconds. This two

octet value represents a 16 bit unsigned number sent with

the most significant octet first.

Priority

The Priority field is one octet long and indicates if multicast

packets have priority over other packets when being sent. A value

of 0 indicates that directed packets have priority. A value of 1

indicates that multicast packets have priority.

3.4. IEEE-MAC-Address-Required

Description

This boolean Configuration Option provides a method for the peer

to require that all NBF datagrams be sent with a 12 octet IEEE MAC

Address header. By default, it is assumed that no MAC header is

required.

A summary of the IEEE-MAC-Address-Required Boolean Configuration

Option format is shown below. The fields are transmitted from left

to right.

0 1

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type Length

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type

4

Length

2

Requirements

By default the NBF datagram is sent without any MAC header

information. The NBF datagram information field is equivalent to

the data field in 802.3, 802.5, and FDDI frames.

If this option is negotiated successfully, each NBF datagram is

sent with a 12 octet IEEE MAC Address header prepended to the

information field. A summary of the information field when using

12 octet IEEE MAC Headers is shown below. The fields are

transmitted from left to right. The MAC Address is in non-

canonical form. This means that the first bit to be transmitted in

every byte is the most significant bit.

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

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Destination MAC Address

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Destination MAC Address Source MAC Address

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Source MAC Address

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

802.3/802.5/FDDI data field...

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Security Considerations

Security issues are not discussed in this memo.

References

[1] Simpson, W., Editor, "The Point-to-Point Protocol (PPP)",

STD 51, RFC1661, July 1994.

[2] Reynolds, J., and J. Postel, "Assigned Numbers", STD 2,

RFC1700, October 1994.

[3] IBM Corp., "IBM Local Area Network Technical Reference",

Third Edition, Document Number SC30-3383-2, November 4, 1988.

[4] Baker, F., and R. Bowen "PPP Bridging Control Protocol (BCP)",

Work in Progress.

Acknowledgments

Some of the text in this document is taken from previous documents

produced by the Point-to-Point Protocol Working Group of the Internet

Engineering Task Force (IETF).

Thomas J. Dimitri (previously at Microsoft Corporation) authored the

original draft.

Special thanks go to coworkers at Microsoft, Bill Simpson

(Daydreamer), Tom Coradetti (DigiBoard), Marty Del Vecchio (Shiva),

Russ Gocht (Shiva) and several members of the IETF PPP Working Group.

Chair's Address

The working group can be contacted via the current chair:

Karl Fox

Ascend Communications

3518 Riverside Drive, Suite 101

Columbus, Ohio 43221

karl@MorningStar.com

karl@Ascend.com

Author's Address

Questions about this memo can also be directed to:

Gurdeep Singh Pall

Microsoft Corporation

1 Microsoft Way

Redmond, WA 98052-6399

EMail: gurdeep@microsoft.com

 
 
 
免责声明:本文为网络用户发布,其观点仅代表作者个人观点,与本站无关,本站仅提供信息存储服务。文中陈述内容未经本站证实,其真实性、完整性、及时性本站不作任何保证或承诺,请读者仅作参考,并请自行核实相关内容。
2023年上半年GDP全球前十五强
 百态   2023-10-24
美众议院议长启动对拜登的弹劾调查
 百态   2023-09-13
上海、济南、武汉等多地出现不明坠落物
 探索   2023-09-06
印度或要将国名改为“巴拉特”
 百态   2023-09-06
男子为女友送行,买票不登机被捕
 百态   2023-08-20
手机地震预警功能怎么开?
 干货   2023-08-06
女子4年卖2套房花700多万做美容:不但没变美脸,面部还出现变形
 百态   2023-08-04
住户一楼被水淹 还冲来8头猪
 百态   2023-07-31
女子体内爬出大量瓜子状活虫
 百态   2023-07-25
地球连续35年收到神秘规律性信号,网友:不要回答!
 探索   2023-07-21
全球镓价格本周大涨27%
 探索   2023-07-09
钱都流向了那些不缺钱的人,苦都留给了能吃苦的人
 探索   2023-07-02
倩女手游刀客魅者强控制(强混乱强眩晕强睡眠)和对应控制抗性的关系
 百态   2020-08-20
美国5月9日最新疫情:美国确诊人数突破131万
 百态   2020-05-09
荷兰政府宣布将集体辞职
 干货   2020-04-30
倩女幽魂手游师徒任务情义春秋猜成语答案逍遥观:鹏程万里
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案神机营:射石饮羽
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案昆仑山:拔刀相助
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案天工阁:鬼斧神工
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案丝路古道:单枪匹马
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:与虎谋皮
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:李代桃僵
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:指鹿为马
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案金陵:小鸟依人
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案金陵:千金买邻
 干货   2019-11-12
 
推荐阅读
 
 
 
>>返回首頁<<
 
靜靜地坐在廢墟上,四周的荒凉一望無際,忽然覺得,淒涼也很美
© 2005- 王朝網路 版權所有