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Using NetBIOS

This document describes the OpenROUTE implementation of NetBIOS over bridged networks and over DLSw networks. It includes the following topics:

About NetBIOS

Reducing NetBIOS Traffic

About NetBIOS Configuration and Monitoring Commands

Displaying the NetBIOS Configuration Prompt

Displaying the NetBIOS Monitoring Prompt

Configuring NetBIOS Filtering and Caching

NetBIOS Commands

About NetBIOS

 NetBIOS was designed only for use on a LAN. It is not a routable protocol and is typically bridged or switched using DLSw.

NetBIOS relies on broadcast frames for most of its functions. While this may not present a problem in LAN environments, these broadcasts can be costly in internetwork environments by causing congestion, as well as increased costs for WAN links.

NetBIOS uses LLC type 1 (LLC1) and LLC type 2 (LLC2) services:

NetBIOS Names

 NetBIOS names are the key to communication between NetBIOS stations. A NetBIOS station must know its name in order to communicate with other NetBIOS stations.

NetBIOS names have 16 ASCII characters. IBM and Microsoft reserve the 16th character of the NetBIOS name.

There are two types of NetBIOS names:

A single NetBIOS station can have multiple individual or group names. The NetBIOS application generates names based on the name or names the network administrator configures.

NetBIOS Name Conflict Resolution

Before a NetBIOS station uses an individual NetBIOS name, it makes sure that the name is unique. To do so, the station repeatedly broadcasts a Name Conflict Resolution frame to all NetBIOS stations. If the station does not receive a response, it presumes the name is unique and it uses the name.

NetBIOS Session Setup Procedure

To establish a NetBIOS session for data transfer types of operations, the NetBIOS client first determines the MAC address of the NetBIOS server. In Token Ring networks, the client also uses source routing techniques to determine the LLC route to the server.

The following is the process of establishing a session:

1. The client repeatedly broadcasts a Spanning Tree Explorer (STE) NetBIOS UI frame that contains the NetBIOS name of the server to all NetBIOS stations.

2. When the server receives the frame, it responds to the client with a corresponding All Routes Explorer (ARE) NetBIOS UI frame that contains the MAC address of the server and, for Token Ring, the route to the server.

The client can then do either of the following:

a. Establish an LLC2 connection to communicate with the server using I-frames.
b. Begin communicating with the server, using specifically-routed NetBIOS UI frames.

Reducing NetBIOS Traffic

 There are two ways to reduce the amount of broadcast NetBIOS traffic:

Table 1 lists the NetBIOS filters that OpenROUTE provides.

Table 1 NetBIOS Filters
Filter Type Filters . . .
MAC Address Frames by either the source or destination MAC address.

Frame Type Specific types of NetBIOS frames.

Duplicate Frame Duplicate frames.

Response Responses for which the router did not forward a NetBIOS broadcast frame.

Byte Frames by byte offset and field length within a frame.

Name Frames by NetBIOS source and destination names.

Once the router filters frames, name caching and route caching control how the router forwards the remaining frames.

Using MAC Filtering describes MAC address filtering.

The following sections describe frame type, duplicate frame, and response filtering, name and route caching, and name and byte filtering.

Frame Type Filtering

Frame type filtering lets you filter the following types of frames:

Name Conflict Resolution

 NetBIOS stations use Name Conflict Resolution frames to make sure their name is unique. Name Conflict Resolution frames are Add-Name-Query, Add-Group-Name-Query, Add-Name Response, and Name-In-Conflict.

Use the following guidelines to determine when to filter Name Conflict Resolution frames:

General Broadcast

 NetBIOS stations use General Broadcast frames to send data to all NetBIOS stations in a network. Stations rarely use this frame, and you can typically filter it. The NetBIOS General Broadcast frame is Datagram-Broadcast.

Trace Control Frames

Trace Control frames terminate NetBIOS traces in all NetBIOS stations in a network. This frame is rarely used and you can typically filter it. The NetBIOS Trace Control frame is Terminate-Trace.

Configuring Frame Type Filtering

For bridged traffic, the router does not filter any of the above frame types as the default. However, if you are bridging NetBIOS traffic on WAN links, it may be beneficial to filter these frames. To turn frame type filtering on or off for bridging, enter set filters bridge.

For DLSw traffic, the router filters all of the above frame types as the default. To turn frame type filtering on or off for DLSw, enter set filters dlsw.

For example:

NetBIOS config>set filters bridge

Filter Name Conflict frames? [No]: yes

Name conflict filtering is              ON

Filter General Broadcast frames? [No]: yes

General broadcast filtering is          ON

Filter Trace Control frames? [No]: yes

Trace control filtering is              ON

Duplicate Frame Filtering

 When a station sends broadcast frames, it typically sends up to 10 (the default is 6) frames at fixed intervals (the default is .5 seconds).

Duplicate frame filtering causes the router to forward only one instance of each frame within a configurable amount of time. Figure 1 shows how duplicate frame filtering reduces the number of broadcast frames forwarded over the DLSw WAN.

Figure 1 Setting Up a NetBIOS Session Over DLSw

Here is the process that the originating NetBIOS client in Figure 1 uses to set up a session with the target NetBIOS server.

1. After verifying that its name is unique, the originating NetBIOS client sends six Name-Query frames at half-second intervals.

2. The originating DLSw router receives the first Name-Query frame and forwards it to the target DLSw router. The originating router filters the remaining five frames.

3. The target DLSw router receives the first Name-Query frame. It then assumes responsibility for setting up the session and sends Name-Query frames to its attached LAN as though it were the originating NetBIOS station.

4. The target NetBIOS station responds to the Name-Query frames with a corresponding Name-Recognized frame that contains its MAC address. For Token Ring frames, the target NetBIOS station also sends the route to the server.

5. The target DLSw router then returns a Specifically-Routed Frame (SRF) to the originating DLSw router, which forwards the frame to the originating NetBIOS station.

How Duplicate Frame Filtering Works

 Duplicate frame filtering works by keeping a database of NetBIOS command frames. These include the following: Name-Query, Status-Query, Datagram, Add-Name-Query, Add-Group-Name-Query, and Name-In-Conflict.

Figure 2 shows the duplicate frame filtering process for bridged traffic. In this example, the router receives six Name-Query frames in half-second intervals. The Duplicate Frame Filter Timeout is set to 1.5 seconds, and the Duplicate Frame Detect Timeout is set to 5 seconds.

Figure 2 Duplicate Frame Filtering Process for Bridged Traffic

Here are the steps for duplicate frame filtering:

1. When the router receives a new frame, it creates an entry for that frame in the duplicate frame database and forwards the frame.

2. The router filters any duplicate frames that it receives within the duplicate frame filter timeout (in this case, 1.5 seconds).

3. If the router receives a duplicate frame after the timer expires, it forwards the frame and resets the timer.

The router repeats this process until the duplicate frame detect timer expires.

For DLSw traffic, the duplicate frame filtering process is the same, except that DLSw does not use the duplicate frame filter timer. DLSw uses only the duplicate frame detect timer. Once the originating router creates an entry, it filters all duplicate frames until the duplicate frame detect timer expires. For DLSw, you can also control how many query frames the target DLSw router sends during a configurable time period.

Configuring Duplicate Frame Filtering

Duplicate frame filtering is always enabled for DLSw traffic. You cannot enable or disable it.

Duplicate frame filtering is disabled for bridged traffic as the default. You can enable or disable it for bridging using the enable duplicate-filtering and disable duplicate-filtering commands.

To change the timers, enter the following:

NetBIOS config>set general

WARNING! Setting Duplicate Frame Filter Timeout to zero...
         disables duplicate frame checking!

Duplicate frame filter timeout value in seconds [1.5]? 
Duplicate frame detect timeout value in seconds [5.0]? 

General parameters set
If you enabled DLSw, the router also prompts you for the following:

Command frame retry count [5]? 
Command frame retry timeout value in seconds [0.5]?
These parameters control how many query frames the target DLSw router sends during a configurable time period.

Response Frame Filtering

NetBIOS stations expect a response frame to Name-Query and Status-Query frames. If a station does not receive a response, it continues to send queries.

If the router receives a response to a command frame that it did not forward, it drops the response and does not forward it.

You cannot disable response frame filtering on the router.

Response Frame Filtering for DLSw

For DLSw traffic, make sure the duplicate frame detect timeout is set high enough for the router to have time to set up a session.

As described in Duplicate Frame Filtering, a target DLSw router takes responsibility for setting up a session.

A router takes responsibility for setting up a session if it matches Name-Query and Name-Recognized frames within the duplicate frame detect timeout period. If the router does not match those frames within that time period, it does not forward Name-Recognized response frames, and it does not set up the session.

The default duplicate frame detect timeout is five seconds. Do not set the duplicate frame detect timeout to zero, or the router will have no time to set up the session. You can increase the duplicate frame detect timeout using the set general command. 

NetBIOS config>set general

WARNING! Setting Duplicate Frame Filter Timeout to zero...
         disables duplicate frame checking!

Duplicate frame filter timeout value in seconds [1.5]? 
Duplicate frame detect timeout value in seconds [5.0]? 

General parameters set

NetBIOS Name Caching and Route Caching

 Name caching and route caching apply to both DLSw and bridging. Once the router filters all possible NetBIOS broadcast frames, it uses NetBIOS name caching and route caching to reduce the number of frames that the router forwards.

With name caching, the router maintains a database of NetBIOS names and routes. Each time the router receives a Name-Recognized frame, it extracts the MAC address and route and enters that information into the database.

When the router receives a Name-Query or Status-Query, it checks to see if the name being queried is already in its database. If it is, route caching converts the frame from an STE frame to a Specifically-Routed Frame (SRF). A timer on the entry invalidates the database information, if the server does not respond before the timer expires.

Enabling Caching

Name caching is always enabled. You cannot disable it. The default for route caching is disabled. Enter enable route-caching to enable it.

Types of Name Cache Entries

There are three types of name cache entries:

There are three types of NetBIOS names kept in the name cache:

The router also distinguishes between local and remote entries:

Adding Name Cache Entries

 You can add permanent or static entries for DLSw neighbors to the name cache. Although the router lets you add entries other than DLSw neighbors, it ignores those entries.

You can enter NetBIOS names in ASCII and hexadecimal, either separately or intermixed. For example, you would need to enter an adapter address in hexadecimal mode. The default data entry mode is ASCII. To enter hexadecimal mode, type a left angle bracket (<). To return to ASCII mode, type a right angle bracket (>).

Enter add cache-entry at the NetBIOS config> prompt to add permanent entries.

Enter add cache-entry at the NetBIOS> prompt to add static entries.

NetBIOS config>add cache-entry

Enter up to 15 characters of NetBIOS name(no wild cards)[]? nbs<F8>
Enter IP Address [0.0.0.0]? 20.15.8.2

Name cache entry has been created

Setting Cache Parameters

 Use the set cache-parms command to change the following parameters:

NetBIOS config>set cache-parms

Significant characters in name [15]? 
Best path aging timeout value in seconds [60.0]? 
Reduced search timeout value in seconds [1.5]? 
Unreferenced entry timeout value in minutes [5000]? 
Max nbr local name cache entries [500]? 
Max nbr remote name cache entries [100]? 

Cache parameters set

Displaying Cache Entries

 The router provides the following commands that let you view cache entries.

From the NetBIOS configuration prompt, you can use the list cache commands in Table 2.

Table 2 NetBIOS List Cache Configuration Commands
Command Displays . . .
list cache all All active entries in the router's name cache, including permanent, static, and dynamic entries.

list cache entry-number A cache entry according to its entry number.

list cache name A cache entry for a specific NetBIOS name.

list cache ip-address A cache entry for a specific IP address.

From the NetBIOS monitoring prompt, you can use the list cache commands in Table 3.

Table 3 NetBIOS List Cache Monitoring Commands
Command Displays . . .
list cache active All active entries in the router's name cache, including permanent, static, and dynamic entries.

list cache config Static and permanent entries. Does not show dynamic entries.

list cache group Entries that exist for NetBIOS group names.

list cache local Local cache entries. Local cache entries are those that the router learns over the bridge.

list cache name A cache entry for a specific NetBIOS name.

list cache remote Remote cache entries. Remote cache entries are those that the router learns over the DLSw WAN.

list cache unknown Entries where the type of NetBIOS entry is unknown. The router considers all entries unknown until it learns the type of entry.

NetBIOS Name Filtering

NetBIOS name filters apply to both bridging and DLSw. You can use them to filter NetBIOS packets that have specific NetBIOS host names. The router examines the source name or destination name field of the following NetBIOS UI packet types:

For information on how to create name filters, see Configuring and Monitoring NetBIOS Name and Byte Filters.

NetBIOS Byte Filtering

NetBIOS byte filters apply to both bridging and DLSw. Byte filtering lets you filter NetBIOS packets based on fields in the NetBIOS packet.

To build a byte filter, you specify

For information on how to create byte filters, see Configuring and Monitoring NetBIOS Name and Byte Filters.

About NetBIOS Configuration and Monitoring Commands

Enter NetBIOS configuration commands at the NetBIOS config> prompt. This document refers to changes you make at the configuration prompt as permanent. Changes you make at this prompt do not take effect immediately. They become part of the router's configuration memory when you restart the router.

Enter NetBIOS monitoring commands at the NetBIOS> prompt. This document refers to changes you make at the monitoring prompt as static. Monitoring commands take effect immediately, but the router does not save them after you restart the router.

Displaying the NetBIOS Configuration Prompt

You can access the NetBIOS config> prompt from either the Bridge or DLSw configuration environments.

Changes you make at the NetBIOS config> prompt affect both bridging and DLSw.

1. To display the NetBIOS config> prompt from the Bridge configuration environment, enter protocol bridge at the Config> prompt and netbios at the Bridge Config> prompt. 

Config>protocol bridge
Transparent Bridge user configuration
Bridge Config>netbios

NetBIOS Support User Configuration

NetBIOS config>
2. To display the NetBIOS config> prompt from the DLSw configuration environment, enter protocol dls at the Config> prompt and netbios at the DLSw config> prompt. 

Config>protocol dls
DLSw protocol user configuration
DLSw config>netbios

NetBIOS Support User Configuration

NetBIOS config>

Displaying the NetBIOS Monitoring Prompt

 You can access the NetBIOS> prompt from either the Bridge or DLSw monitoring environments.

Changes you make at the NetBIOS> prompt affect both bridging and DLSw.

1. To display the NetBIOS> prompt from the Bridge monitoring environment, enter protocol bridge at the + prompt and netbios at the Bridge> prompt. 

+protocol bridge
Bridge>netbios

NetBIOS Support User Console

NetBIOS>
2. To display the NetBIOS> prompt from the DLSw monitoring environment, enter protocol dls at the + prompt and netbios at the DLSw> prompt. 

+protocol dls
DLSw>netbios

NetBIOS Support User Console

NetBIOS>

Configuring NetBIOS Filtering and Caching

 You can configure the following NetBIOS filtering and caching parameters:

Configuring NetBIOS for DLSw

 If you are sending NetBIOS traffic over DLSw, you can also configure the following parameter, according to the procedures below:

Adding Name Cache Entries for DLSw Neighbors

 Add name cache entries for DLSw neighbors. You can add multiple entries with different IP addresses for a single NetBIOS name. This allows DLSw to send the frame to multiple DLSw neighbors.

You can enter NetBIOS names in ASCII and hexadecimal, either separately or intermixed. See cache-entry for more information. NetBIOS names are case sensitive and must match the case of the network NetBIOS names.

NetBIOS config>add cache-entry


Enter up to 15 characters of NetBIOS name (no wild cards)[] Accounting<0000>


Enter IP Address [0.0.0.0]? 20.2.1.3

Name cache entry has been created

Opening NetBIOS SAPs

 At the DLSw config> prompt, open NetBIOS SAPs on both sides of the link to enable DLSw to transmit NetBIOS frames. 

DLSw config>open-sap
Interface # [0]? 
Enter SAP in hex(range 0-F4),'SNA', 'NB' or 'LNM'[4]? nb
SAP F0 opened on interface 0

Setting a Priority for SNA and NetBIOS Sessions

 Prioritize SNA and NetBIOS traffic to prevent one type of session from using too much of the available bandwidth during network congestion.

To do so, at the DLSw config> prompt, enter set priority to set a priority of Critical, High, Medium, or Low for SNA sessions and NetBIOS sessions. Also, set a message allocation that corresponds to a session's priority. 

DLSw config>set priority
Priority for SNA DLSw sessions (C/H/M/L) [M]?  H 
Priority for NetBIOS DLSw sessions (C/H/M/L) [M]? M
Message allocation by C/H/M/L priority (4 digits) [4/3/2/1]? 
Maximum NetBIOS frame size (516, 1470, 2052, or 4399) [2052]?
The router uses the priority and message allocation to selectively limit the burst-length of specific types of traffic. For example, if you assign

the router processes 4 SNA frames before it processes 2 NetBIOS frames. Once the router processes 2 NetBIOS frames, it processes 4 SNA frames, and so on. In this scenario, the router dedicates two-thirds of available bandwidth to SNA traffic (a ratio of 4 to 2). Note that the router counts frames, rather than bytes, when allocating bandwidth according to the priorities you assign.

You can change the message allocation for sessions from the default of 4/3/2/1. You must always enter four digits, between 1 and 9, in descending order. For example, if the SNA priority is Critical, the NetBIOS traffic is Medium, and you change the message allocation to 8/7/6/5, the router processes 8 SNA frames before it processes 6 NetBIOS frames, and so on.

Setting the Maximum NetBIOS Frame Size

To change the maximum NetBIOS frame size, enter set priority at the DLSw config> prompt. The default is 2052. Set this parameter to the largest frame size you expect to need, and no larger. Setting the frame size larger than needed reduces the number of available buffers.

Setting the Memory Allocation for NetBIOS UI Frames

Enter set memory at the DLSw config> prompt to set the number of bytes the router allocates as a buffer for NetBIOS UI frames. If the TCP transmit buffer becomes full, the router uses this buffer to collect NetBIOS UI frames.

Note that the number of bytes allocated for NetBIOS is global, and not per session. 

DLSw config>set memory
Number of bytes to allocate for DLSw (at least 26368) [141056]? 
Number of bytes to allocate per LLC session [8192]? 
Number of bytes to allocate per SDLC session [4096]? 
Number of bytes to allocate for NetBIOS UI-frames [40960]?

NetBIOS Commands

 Table 4 lists the NetBIOS commands. Not all parameters apply to all router platforms. Press Space twice after you type a command to display the available parameters for each command for your router. Enter help for information about using the command line interface.

[C] means the command is available at the NetBIOS config> prompt.

[M] means the command is available at the NetBIOS> prompt.

Table 4 NetBIOS Commands

Command Function
Add [C] [M] Adds cache entries to the router's name cache.

Delete [C] [M] Deletes cache entries that you added using the add cache-entry command.

Disable [C] [M] Disables duplicate frame filtering and route caching.

Enable [C] [M] Enables duplicate frame filtering and route caching.

Exit [C] [M] Returns to the previous prompt.

List [C] [M] Displays various cache entries and configuration information depending on whether you are at the configuration prompt or the monitoring prompt.

Set [C] [M] Configures parameters for name caching, duplicate frame filtering, and frame type filtering. Also, displays the NETBIOS Filter config> prompt.

Add [C] [M]

Adds a new name cache entry to the router's permanent or static configuration.

From the configuration prompt, adds a permanent entry. From the monitoring prompt, adds a static entry.

Syntax: add

cache-entry

cache-entry

Adds a new entry to the router's name cache. You can add name cache entries for DLSw neighbors only. The router ignores entries that you add for bridge traffic.

You can add multiple entries with different IP addresses for a single NetBIOS name. This allows DLSw to send the frame to multiple DLSw neighbors.

You can enter NetBIOS names in ASCII and hexadecimal, either separately or intermixed. For example, you would need to enter an adapter address in hexadecimal mode. The default data entry mode is ASCII. To enter hexadecimal mode, type a left angle bracket (<). To return to ASCII mode, type a right angle bracket (>).

Note: NetBIOS names are case sensitive and must match the case of the network NetBIOS names.

Example: add cache-entry

Enter up to 15 characters of NetBIOS name (no wild cards)[] nbserve<F1>
Enter IP Address [0.0.0.0]? 20.2.1.3

Name cache entry has been created

Delete [C] [M]

Deletes name cache entries from the router's permanent or static configuration.

Delete [C]

Deletes name cache entries from the router's permanent configuration. The router prompts for a record number, which is the number of the entry you want to delete. To see a list of entry numbers, enter list cache all.

Syntax: delete

cache-entry
Example: delete cache-entry

Enter name cache record number [1]? 2

Name cache entry has been deleted

Delete [M]

Deletes name cache entries from the router's static configuration or active cache. The router prompts for a cache entry name. To see a list of entries, enter list cache conf or list cache active.

Note: NetBIOS names are case sensitive.

Syntax: delete

cache-entry
Example: delete cache-entry

Enter up to 15 characters of NetBIOS name (no wild cards) []? ADMIN
Name cache entry NOT found in Active list for name entered
Name cache entry has NOT been deleted from Active list

Static name cache entry deleted from Config list

Disable [C] [M]

Disables duplicate frame filtering or route caching for the bridge.

Syntax: disable

duplicate-filtering
route-caching

duplicate-filtering

 Disables duplicate frame filtering for bridging. Duplicate frame filtering is always enabled for DLSw traffic. You cannot enable or disable it.

Example: disable duplicate-filtering

Duplicate frame filtering is           OFF

route-caching

 Disables route caching for bridging. Route caching is the process of converting broadcast frames to Specifically-Routed Frames (SRF) using the entries in the NetBIOS name cache. Route caching is always enabled for DLSw traffic. You cannot enable or disable it.

Example: disable route-caching

Route caching is                       OFF

Enable [C] [M]

Enables duplicate frame filtering or route caching for the bridge.

Syntax: enable

duplicate-filtering
route-caching

duplicate-filtering

 Enables duplicate frame filtering for bridging. Duplicate frame filtering is always enabled for DLSw. You cannot enable and disable it.

Example: enable duplicate-filtering

Duplicate frame filtering is            ON

route-caching

 Enables route caching for bridging. Route caching is always enabled for DLSw. You cannot enable or disable it. Route caching is the process of converting broadcast frames to Specifically-Routed Frames (SRF), using the NetBIOS name cache.

Example: enable route-caching

Route caching is                        ON

Exit [C] [M]

Returns to the previous prompt.

Syntax: exit

Example: exit

List [C] [M]

Displays various cache entry and configuration information, depending on whether you are at the configuration prompt or the monitoring prompt.

See NetBIOS Name Caching and Route Caching for a description of the types of cache entries.

List [C]

Displays all cache entries or displays cache entries by type of entry. Displays filter configuration information or general configuration information.

Syntax: list

cache all
cache entry-number
cache name
cache ip-address
filters all
filters bridge
filters dlsw
general

cache all

 Displays all active entries in the router's permanent name cache. Does not display static or dynamic entries.

The router displays all hexadecimal data in angle brackets. The number in angle brackets just before the IP address is the 16th character of the NetBIOS name. IBM and Microsoft reserve the 16th character of the NetBIOS name, and it always appears in hexadecimal.

Example: list cache all

Entry  Name                 IP Address
-----  -------------------  ---------------
    1  Accounting     <00>  20.2.1.3       
    2  Notes<00000>   <00>  20.2.3.4

cache entry-number record#

 Displays a cache entry according to its entry number. Enter list cache all to see a list of all entry numbers.

Example: list cache entry-number

Enter name cache record number [1]? 1

Entry  Name                 IP Address
-----  -------------------  ---------------
    1  Accounting     <00>  20.2.1.3

cache name name

 Displays a cache entry for a specific NetBIOS name. Use the following wildcards to simplify your search:
*

 Stands for any character string. For example, "San*" could produce:
San Francisco
Santa Fe
San Juan

?

 Stands for any one character.

$

 Must coincide with the last character in a name.

Following are examples of valid uses of wildcards that match San Francisco:
*Fran*

 S??*?????????

San?Fran?isco

 S?*

S*

S?a?n?F?a?c?s?

*o

 ????????????

isco?

 isco$

San?F*

 *

Use as many wildcards as you like, up to the maximum number of characters in a NetBIOS name (15 or 16, depending on how many significant characters you configured using the set cache-parms command).

Note: NetBIOS names are case sensitive.

Example: list cache name

Enter up to 15 characters of NetBIOS name (wild cards ok) []? Acc*

Entry  Name                 IP Address
-----  -------------------  ---------------
    1  Accounting     <00>  20.2.1.3

cache ip-address

 Lets you display an entry for a specific IP address.

Example: list cache ip-address

Enter IP Address [0.0.0.0]? 20.2.1.3

Entry  Name                 IP Address
-----  -------------------  ---------------
    1  Accounting     <00>  20.2.1.3

filters all

 Displays whether or not frame type filtering is on or off for both bridging and DLSw. Use the set filters bridge and set filters dlsw commands to turn these filters on or off.

Example: list filters all

Bridge name conflict filtering is       OFF
Bridge general bcast filtering is       OFF
Bridge trace control filtering is       OFF

DLS name conflict filtering is          ON
DLS general bcast filtering is          ON
DLS trace control filtering is          ON

filters bridge

 Displays whether or not frame type filtering is on or off for bridging. Enter set filters bridge to turn these filters on or off.

Example: list filters bridge

Bridge name conflict filtering is       OFF
Bridge general bcast filtering is       OFF
Bridge trace control filtering is       OFF

filters dlsw

 Displays whether or not frame type filtering is on or off for both DLSw. Enter set filters dlsw to turn these filters on or off.

Example: list filters dlsw

DLS name conflict filtering is          ON
DLS general bcast filtering is          ON
DLS trace control filtering is          ON

general

 Displays the current NetBIOS caching and filtering configuration.

Example: list general

Bridge-only Information:

Bridge duplicate filtering is            OFF
Bridge duplicate frame filter t/o       1.5 seconds

DLS-only Information:

DLS command frame retry count            5
DLS max remote name cache entries      100
DLS command frame retry timeout        0.5 seconds

DLS-Bridge Common Information:

Route caching is                        OFF
Significant characters in name           15
Max local name cache entries            500
Duplicate frame detect timeout          5.0 seconds
Best path aging timeout                60.0 seconds
Reduced search timeout                  1.5 seconds
Unreferenced entry timeout             5000 minutes
Note: The DLS-only Information appears only if you enabled DLSw.

List [M]

Displays various types of cache entries, filter configuration, general configuration information, or statistics on caching and filtering.

Syntax: list

cache active
cache config
cache group
cache local
cache name
cache remote
cache unknown
filters all
filters bridge
filters dlsw
general
statistics cache
statistics frames bridge
statistics frames dlsw
statistics general bridge
statistics general dlsw

cache active

 Displays all active entries in the router's name cache, including dynamic, static, and permanent entries.

The router displays all hexadecimal data in angle brackets. The number in angle brackets just before the IP address is the 16th character of the NetBIOS name. IBM and Microsoft reserve the 16th character of the NetBIOS name, and it always appears in hexadecimal.

If the Name Type field does not specify local, it is a remote entry. For a description of the fields in this display, see the list cache name command on page 28.

Example: list cache active

Cnt NetBIOS Name         Name Type          Entry Type
--- -------------------  -----------------  ----------
 1  HYPERION       <01>  INDIVIDUAL LOCAL   DYNAMIC   
 2  LANGROUP<F8>   <00>  UNKNOWN            STATIC
 3  ACCOUNTING<000><00>  GROUP              PERMANENT

cache config

 Displays all static and permanent name cache entries. Does not show dynamic entries.

The router displays all hexadecimal data in angle brackets. The number in angle brackets just before the IP address is the 16th character of the NetBIOS name. IBM and Microsoft reserve the 16th character of the NetBIOS name, and it always appears in hexadecimal.

Example: list cache config

Name                IP Address      Source     Last Mod
------------------  --------------  ---------  ---------
Admin<00000>  <00>  20.3.120.8      STATIC     ADDED  
Finance       <01>  20.4.96.8       PERMANENT  MODIFIED 
Notes         <00>  20.8.210.3      PERMANENT  UNCHANGED

cache group

 Displays cache entries that exist for NetBIOS group names. For a description of the fields in this display, see the list cache name command.

Example: list cache group

Cnt  NetBIOS Name     Entry Type   Loc Path St  Rem Path St
---  ---------------  -----------  -----------  -----------
  2  HYPERION   <01>  DYNAMIC      UNKNOWN         GROUP
  3  EXCEL      <  >  DYNAMIC      GROUP           GROUP

cache local

 Displays local cache entries. Local cache entries are those that the router learns via the local bridge network. For a description of the fields in this display, see the list cache name command.

For NetBIOS clients the Local Path State is always Unknown and the MAC Address and Routing Information fields are always empty.

Example: list cache local

Cnt  NetBIOS Name     Loc Path St  MAC Address  Routing Information
---  ---------------  -----------  ----------- --------------------
  2  HYPERION   <01>  UNKNOWN

cache name name

 Displays a cache entry for a specific NetBIOS name. Use the following wildcards to simplify your search:
*

 Stands for any character string. For example, "San*" could produce:
San Francisco
Santa Fe
San Juan

?

 Stands for any one character.

$

 Must coincide with the last character in a name.

Following are examples of valid uses of wildcards that match San Francisco:
*Fran*

 S??*?????????

San?Fran?isco

 S?*

S*

 S?a?n?F?a?c?s?

*o

 ????????????

isco?

 isco$

San?F*

 *

Use as many wildcards as you like, up to the maximum number of characters in a NetBIOS name (15 or 16, depending on how many significant characters you configured using the set cache-parms command).

Note: NetBIOS names are case sensitive.

Example: list cache name

Enter up to 15 characters of NetBIOS name (wild cards ok) []? HYP*


NetBIOS Name         Name Type          Entry Type
-------------------  -----------------  ----------
HYPERION       <01>  INDIVIDUAL REMOTE   DYNAMIC   

Count of name cache entry hits                          2

Age of name cache entry                                 689
Age of name cache last reference                        85

Local path information:

  Loc Path St  Timestamp  MAC Address   LFS   Routing Information
  -----------  ---------  -----------   ---      -----------------------
  UNKNOWN          689

Remote path information:

  Rem Path St  Timestamp  LFS    IP Address(es)
  -----------  ---------  ---        --------------
  BEST FOUND      85      2 52    20.55.27.33
NetBIOS Name

 The entry's NetBIOS name.

Name Type

 Type of NetBIOS name. Possible types are

Individual— NetBIOS individual name.
Group— NetBIOS group name.
Unknown— The router does not have information about the name, indicating that a search for the name is not complete.
Local— An entry the router can reach locally via the bridge network.
Remote— An entry the router can reach remotely via a DLSW TCP session.
Entry Type

 Possible entry types are

Permanent— Entries that you add at the NetBIOS config> prompt using the add cache-entry command.
Static— Entries that you add at the NetBIOS> prompt using the add cache-entry command.
Dynamic— Entries that the router learns through Name-Query and Name-Recognized processing.
Count of name cache entry hits

 Number of times the entry was referenced.

Age of name cache entry

 Number of timer ticks since the entry was added. Timer ticks vary according to hardware platform.

Age of name cache last reference

 Number of timer ticks since an entry was last referenced. Timer ticks vary according to hardware platform.

Local path information:

Loc Path St

 Local Path State. Possible states are

Best Found— The router found the best route to this station.
Unknown— The router has not yet found the best route to this station.
Group— The router does not search for a best path for group names.
Search Ltd— The router is conducting a limited search for this NetBIOS name. See the set cache-parms command for more information on a reduced search.
Search All— The router is conducting a full search. When the set cache-parms command's reduced search timer expires, the router conducts a full search.
Timestamp

 Number of timer ticks since the software last updated an entry. Timer ticks vary according to hardware platform.

MAC Address

 If the entry is a server, displays the MAC address of the server.

LFS

 Largest Frame Size that the router can use for the entry.

Routing
Information

 Displays standard Routing Information Field (RIF) information.

Remote path information:

Rem Path St

 Remote Path State. Possible states are the following:

Best Found— The router found the best route to this station.
Unknown— The router has not yet found the best route to this station.
Group— The router does not search for a best path for group names.
Search Ltd— The router is conducting a limited search for this NetBIOS name. See the set cache-parms command for more information on a reduced search.
Search All— The router is conducting a full search. When the set cache-parms command's reduced search timer expires, the router conducts a full search.
Timestamp

 Number of timer ticks since an entry was last updated. Timer ticks vary according to hardware platform.

LFS

 Largest Frame Size that can be used for the entry.

IP Address

 IP address of the DLSw partner.

cache remote

Displays cache entries that the router learns over the DLSw WAN. If the router has found the best path, it displays the IP address associated with the DLSw neighbor that can reach the NetBIOS station. For a description of the fields in this display, see the list cache name command.

Example: list cache remote

Cnt  NetBIOS Name     Entry Type      Rem Path St       IP Address(es)
---  ---------------  --------------  --------------    --------------
  2  HYPERION   <01>  STATIC          BEST FOUND        20.55.27.33
  3  EXCEL      <00>  STATIC          SEARCH ALL        cache unknown
Displays cache entries where the type of NetBIOS name is unknown. The router enters all dynamic entries as Unknown until it learns the type of name. It then marks entries as local, remote, or group. For a description of the fields in this display, see the list cache name command.

Example: list cache unknown

Cnt  NetBIOS Name   Entry Type   Loc Path St Rem Path St  IP Address(es)
---  -------------  -----------  ----------- -----------  --------------
  2  HYPERION   <01>  STATIC       UNKNOWN     BEST FOUND   23.21.21.2
  3  EXCEL      <00>  STATIC       UNKNOWN     UNKNOWN

filters all

 Displays whether or not frame type filtering is on or off for both bridging and DLSw. Use the set filters bridge and set filters dlsw commands to turn these filters on or off.

Example: list filters all

Bridge name conflict filtering is       OFF
Bridge general bcast filtering is       OFF
Bridge trace control filtering is       OFF

DLS name conflict filtering is          ON
DLS general bcast filtering is          ON
DLS trace control filtering is          ON

filters bridge

 Displays whether or not frame type filtering is on or off for bridging. Use the set filters bridge command to turn these filters on or off.

Example: list filters bridge

Bridge name conflict filtering is       OFF
Bridge general bcast filtering is       OFF
Bridge trace control filtering is       OFF

filters dlsw

 Displays whether or not frame type filtering is on or off for both DLSw. Use the set filters dlsw command to turn these filters on or off.

Example: list filters dlsw

DLS name conflict filtering is          ON
DLS general bcast filtering is          ON
DLS trace control filtering is          ON

general

 Displays the current NetBIOS caching and filtering configuration.

Example: list general

Bridge-only Information:

Bridge duplicate filtering is          OFF
Bridge duplicate frame filter t/o      1.5 seconds

DLS-only Information:

DLS command frame retry count            5
DLS max remote name cache entries      100
DLS command frame retry timeout        0.5 seconds

DLS-Bridge Common Information:

Route caching is                       OFF
Significant characters in name          15
Max local name cache entries           500
Duplicate frame detect timeout         5.0 seconds
Best path aging timeout               60.0 seconds
Reduced search timeout                 1.5 seconds
Unreferenced entry timeout            5000 minutes
Note: The DLS-only Information appears only if you enabled DLSw.

statistics cache

 Lists name cache statistics.

Example: list statistics cache

Local name cache entries                 1
Remote name cache entries                1
Local individual names                   1
Remote individual names                  0
Group names                              0
Unknown names                            1
Name cache hits                       2194
Name cache misses                        2

statistics frames bridge

 Lists name cache statistics for bridging.

Example: list statistics frames bridge

Frames in cache                          0
Name query frames                        0
Status query frames                      0
Add name frames                          0
Add group name frames                    0
Name in conflict frames                  0
Frames not filtered as duplicates        0

statistics frames dlsw

 Lists name cache statistics for DLSw.

Example: list statistics frames dlsw

Name query frames                        0
Status query frames                      0
Add name frames                          0
Add group name frames                    0
Name in conflict frames                  0
Frames not filtered as duplicates        0

statistics general bridge

 Displays frame counts for bridging.

Example: list statistics general bridge

Frames received                       1339
Frames discarded                         0
Frames forwarded to bridge            1339
Frames forwarded to DLS               1339

statistics general dlsw

 Displays frame counts for DLSw.

Example: list statistics general dlsw

Frames received                       1339
Frames discarded                         0
Frames forwarded to bridge            1339

Set [C] [M]

Sets name caching parameters, turns frame type filtering on or off for either bridging or DLSw, and adjusts duplicate frame filtering timers and frame retry timers. Also, displays the NetBIOS name and byte filtering prompt.

Syntax: set

cache-parms
filters bridge
filters byte
filters dlsw
filters name
general

cache-parms

Sets name caching parameters that apply to bridging or DLSw.

Example: set cache-parms

Significant characters in name [15]? 
Best path aging timeout value in seconds [60.0]? 
Reduced search timeout value in seconds [1.5]? 
Unreferenced entry timeout value in minutes [5000]? 
Max nbr local name cache entries [500]? 
Max nbr remote name cache entries [100]? 

Cache parameters set
Significant characters in name

 Determines whether the router considers 15 or 16 characters when it looks up the NetBIOS name. If you enter

The default is 15.

Best path aging timeout

 Amount of time in seconds the router considers the address and route for a local name cache entry to be the best path to that station. When this timer expires, the router deletes the name cache entry and attempts to discover a new best path for the NetBIOS name.

To determine the best path, the router considers transmission time between nodes on all possible routes connecting those nodes, as well as largest frame size. The router does not consider a path suitable if it cannot accommodate the largest NetBIOS frame that could be transmitted over the path.

The default is 60 seconds. The range is 1.0 to 100,000.0 seconds.

Reduced search timeout

 When the router receives a Name-Query, Status-Query, or Datagram during the timeout period, it searches based on current NetBIOS name cache information.

If the router receives a duplicate frame after this timer expires, it presumes the previous route is no longer valid and it widens its search. The router forwards the duplicate frame to both bridges and DLSw. DLSw broadcasts the corresponding SSP message to all possible DLSw partners.

The default is 1.5 seconds. The range is 1.0 to 100.0 seconds.

Unreferenced entry timeout

 The router keeps a name that is not referenced in its cache for this length of time before deleting it. If the cache fills up, the router removes entries sooner.

The default is 5,000 minutes. The range is 100 to 100,000 minutes.

Max nbr local name cache entries

 Maximum number of local entries the router saves in the name cache. Local entries are those that the router learns over the bridge.

The default is 500. The range is 1 to 30,000. To optimize memory usage, processor usage, and the amount of broadcast traffic, set this number as close as possible to the total number of NetBIOS stations (servers and clients) that are active on this router's local bridge network.

Max nbr remote name cache entries

 Maximum number of remotely-learned entries, group name entries, and unknown entries.

The default is 100. The range is 1 to 30,000. To optimize memory usage, processor usage, and the amount of broadcast traffic, set this number to the number of remote NetBIOS clients on this router's local bridge network, plus about 25%.

filters bridge

Turns on or off frame-type filtering for bridging.

Example: set filters bridge

Filter Name Conflict frames? [No]: y

Name conflict filtering is             ON

Filter General Broadcast frames? [No]: 

General broadcast filtering is         OFF

Filter Trace Control frames? [No]: 

Trace control filtering is             OFF

filters byte

 From the NetBIOS config> prompt, displays the NetBIOS filtering configuration prompt (NETBIOS Filter config>).

From the NetBIOS> prompt, displays the NetBIOS filtering monitoring prompt (NETBIOS Filter>).

These prompts allow you to set up NetBIOS name and byte filters.

See Configuring and Monitoring NetBIOS Name and Byte Filters for information on the commands available at this prompt.

Example: set filters byte

NETBIOS Filtering configuration
NETBIOS Filter config>

filters dlsw

 Sets frame-type filters for DLSw traffic.

Example: set filters dlsw

Filter Name Conflict frames? [Yes]: 

Name conflict filtering is              ON

Filter General Broadcast frames? [Yes]: 

General broadcast filtering is          ON

Filter Trace Control frames? [Yes]: 

Trace control filtering is              ON

filters name

 From the NetBIOS config> prompt, displays the NETBIOS Filter config> prompt.

From the NetBIOS> prompt, displays the NETBIOS Filter> prompt.

These prompts allow you to set up NetBIOS name and byte filters.

See Configuring and Monitoring NetBIOS Name and Byte Filters for a description of the commands available at this prompt.

Example: set filters name

NETBIOS Filtering configuration
NETBIOS Filter config>

general

 Sets the duplicate frame timeout, duplicate frame detect timeout, and the command frame retry count and timeout. See Duplicate Frame Filtering for information on how duplicate frame filters work.

Example: set general

WARNING! Setting Duplicate Frame Filter Timeout to zero...
         disables duplicate frame checking!

Duplicate frame filter timeout value in seconds [1.5]? 

Duplicate frame detect timeout value in seconds [5.0]? 

General parameters set
If DLSw is enabled, the software also prompts you as follows:

Command frame retry count [5]? 
Command frame retry timeout value in seconds [0.5]?
Duplicate frame filter timeout

 Applies only to bridged traffic if duplicate-filtering is enabled.

During this timeout period, the router filters all duplicate frames it receives.

The range is 0.0 to 100.0 seconds. Zero disables duplicate frame checking. The default is 1.5 seconds.

Duplicate frame detect timeout

Applies to both bridged and DLSw traffic.

Amount of time the router saves entries in its duplicate frame filter database. When this timer expires, the router creates new entries for new frames that it receives.

The range is 0.0 to 100.0 seconds. The default is 5 seconds.

Command frame retry count

 Applies only to DLSw traffic.

Number of duplicate NetBIOS UI frames the target DLSw router sends to its locally-attached LAN. The router sends these frames at intervals specified by the command frame retry timeout.

The range is 0 to 10. The default is 5.

Command frame retry timeout

 Applies only to DLSw traffic.

This is the interval at which a neighbor DLSw router retries sending duplicate NetBIOS UI frames to its local bridge network.

The range is 0.0 to 10.0 seconds. The default is .5 seconds.


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