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Router Products Command Reference
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About This Manual
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Router Product Overview
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User Interface Commands
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System Image, Microcode Image, and Configuration File Load Comm
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Terminal Line and Modem Support Commands
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System Management Commands
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Interface Commands
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ATM Commands
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DDR Commands
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Frame Relay Commands
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ISDN Commands
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LAN Emulation Commands
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SMDS Commands
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X.25 Commands
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Apollo Domain Commands
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AppleTalk Commands
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Banyan VINES Commands
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DECnet Commands
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IP Commands
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IP Routing Protocols Commands
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ISO CLNS Commands
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Novell IPX Commands
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XNS Commands
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Source-Route Bridging Commands
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Remote Source-Route Bridging Commands
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DLSw+ Configuration Commands
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STUN and BSTUN Configuration Commands
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LLC2 and SDLC Configuration Commands
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IBM Network Media Translation Commands
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DSPU and SNA Service Point Configuration Commands
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SNA Frame Relay Access Support Commands
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APPN Configuration Commands
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IBM Channel Attach Configuration Commands
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References and Recommended Reading
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Ethernet Type Codes
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Regular Expressions
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ASCII character Set
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Platform Support
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Switching Appendix
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Table Of Contents
clns net (global configuration command)
clns net (interface configuration command)
clns route (interface static route)
clns route (to enter a static route)
ISO CLNS Commands
The International Organization for Standardization (ISO) Connectionless Network Service (CLNS) protocol is a standard for the network layer of the Open System Interconnection (OSI) model.
Use the commands in this chapter to configure and monitor ISO CLNS networks. For ISO CLNS protocol configuration information and examples, refer to the "Configuring ISO CLNS" chapter of the Router Products Configuration Guide.
area-password
Use the area-password router configuration command to configure the area authentication password. The no area-password command disables the password.
area-password password
no area-password [password]Syntax Description
Default
No area authentication password is defined.
Command Mode
Router configuration
Usage Guidelines
This password is inserted in Level 1 (station router level) link state PDUs (LSPs), complete sequence number PDUs (CSNPs), and partial sequence number PDUs (PSNP).
Example
The following example assigns an area authentication password:
router isisarea-password angelRelated Command
clear clns cache
Use the clear clns cache EXEC command to clear and reinitialize the CLNS routing cache.
clear clns cache
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Example
The following example clears the CLNS routing cache:
clear clns cacheRelated Command
clear clns es-neighbors
Use the clear clns es-neighbors EXEC command to remove ES neighbor information from the adjacency database.
clear clns es-neighbors
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Example
The following example removes the ES neighbor information from the adjacency database:
clear clns es-neighborsRelated Commands
clear clns neighbors
show clns es-neighborsclear clns is-neighbors
Use the clear clns is-neighbors EXEC command to remove IS neighbor information from the adjacency database.
clear clns is-neighbors
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Example
The following example removes the IS neighbor information from the adjacency database:
clear clns is-neighborsRelated Commands
clear clns neighbors
show clns is-neighborsclear clns neighbors
Use the clear clns neighbors EXEC command to remove CLNS neighbor information from the adjacency database.
clear clns neighbors
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Example
The following example removes the CLNS neighbor information from the adjacency database:
clear clns neighborsRelated Commands
clear clns es-neighbors
clear clns is-neighbors
show clns neighborsclear clns route
Use the clear clns route EXEC command to remove all of the dynamically derived CLNS routing information.
clear clns route
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Example
The following example removes all of the dynamically derived CLNS routing information:
clear clns routeRelated Command
clns access-group
Use the clns access-group interface configuration command to filter transit CLNS traffic going either into or out of the router or both on a per-interface basis. Use the no form of this command to disable filtering of transit CLNS packets.
clns access-group name [in | out]
no clns access-group name [in | out]Syntax Description
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command has no effect on any CLNS packets sourced by the router. It applies only to packets forwarded by the router. Fast switching is still supported with access groups in place, but its performance will be impacted based on the complexity of the filters.
Filter sets and expressions are described in this manual in the descriptions for the clns filter-expr, clns filter-set, and clns template-alias global configuration commands.
Example
The following example shows how to enable forwarding of frames received on Ethernet 0 that had a source address of anything other than 38.840F, and a destination address that started with 47.0005 or 47.0023, but nothing else:
clns filter-set US-OR-NORDUNET permit 47.0005...clns filter-set US-OR-NORDUNET permit 47.0023...clns filter-set NO-ANSI deny 38.840F...clns filter-set NO-ANSI permit defaultclns filter-expr STRANGE source NO-ANSI and destination US-OR-NORDUNETinterface ethernet 0clns access-group STRANGE inRelated Commands
clns filter-expr
clns filter-set
clns template-aliasclns adjacency-filter
Use the clns adjacency-filter interface configuration command to filter the establishment of CLNS end system (ES) and intermediate system (IS) adjacencies. Use the no form of this command to disable this filtering.
clns adjacency-filter {es | is} name
no clns adjacency-filter {es | is} nameSyntax Description
es
End system adjacencies are to be filtered.
is
Intermediate system adjacencies are to be filtered.
name
Name of the filter set or expression to apply.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
Filtering is performed on full NSAP addresses. If filtering should only be performed on system IDs or any other substring of the full NSAP address, the wildcard-matching capabilities of filter sets should be used to ignore the insignificant portions of the NSAP addresses.
Filter sets and expressions are described in this manual in the descriptions for the clns filter-expr, clns filter-set, and clns template-alias global configuration commands.
Example
The following example builds a filter that accepts end system adjacencies with only two systems, based only on their system IDs:
clns filter-set ourfriends ...0000.0c00.1234.**clns filter-set ourfriends ...0000.0c00.125a.**interface ethernet 0clns adjacency-filter es ourfriendsRelated Commands
clns filter-expr
clns filter-set
clns template-aliasclns checksum
Use the clns checksum interface configuration command to enable checksum generation when ISO CLNS routing software sources a CLNS packet. Use the no form of this command to disable checksum generation.
clns checksum
no clns checksumSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Interface configuration
Usage Guidelines
This command has no effect on routing packets (ES-IS, ISO-IGRP, and IS-IS) sourced by the system. It applies to pings and trace route packets.
Example
The following example shows how to enable checksum generation:
interface ethernet 0clns checksumclns cluster-alias
Use the clns cluster-alias interface configuration command to allow multiple systems to advertise the same system ID as other systems in end-system hello messages. The no form of this command disables cluster aliasing.
clns cluster-alias
no clns cluster-aliasSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This feature caches multiple ES adjacencies with the same network service access point (NSAP) but different subnetwork point of attachment (SNPA) addresses. When a packet is destined to the common NSAP address, the router load-splits the packets among the different SNPA addresses. A router that supports this capability forwards traffic to each system.
If DECnet Phase V cluster aliases are disabled on an interface, end-system hello packet information is used to replace any existing adjacency information for the NSAP. Otherwise, an additional adjacency (with a different SNPA) is created for the same NSAP.
Example
The following example shows how cluster aliasing is enabled on specified interfaces:
clns nsap 47.0004.004d.0001.0000.0c00.1111.00clns routinginterface ethernet 0clns cluster-aliasinterface ethernet 1clns cluster-aliasclns configuration-time
Use the clns configuration-time global configuration command to specify the rate at which ES hellos (ESHs) and IS hellos (ISHs) are sent. You can restore the default value by specifying the no form of this command.
clns configuration-time seconds
no clns configuration-timeSyntax Description
Default
60 seconds
Command Mode
Global configuration
Example
The following example specifies that ESHs and ISHs are to be sent every 100 seconds:
clns configuration-time 100Related Commands
clns esct-time
clns holding-timeclns congestion-threshold
Use the clns congestion-threshold interface configuration command to set the congestion experienced bit if the output queue has more than the specified number of packets in it. A number value of zero or the no form of this command prevents this bit from being set. Use the no form of this command to remove the parameter setting and set it to 0.
clns congestion-threshold number
no clns congestion-threshold
number
Number of packets that are allowed in the output queue before the system sets the congestion-experienced bit. The value zero (0) prevents this bit from being set.
Syntax Description
Default
4 packets
Command Mode
Interface configuration
Usage Guidelines
If a router configured for CLNS experiences congestion, it sets the congestion experienced bit. The congestion threshold is a per-interface parameter set by this interface configuration command. An error PDU is sent to the sending router and the packet is dropped if the number of packets exceeds the threshold.
Example
The following example sets the congestion threshold to 10:
interface ethernet 0clns congestion-threshold 10clns dec-compatible
Use the clns dec-compatible interface configuration command to allow ISHs sent and received to ignore the N-selector byte. Use the no form of this command to disable this feature.
clns dec-compatible
no clns dec-compatibleSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Example
The following example enables DEC-compatible mode:
interface ethernet 0clns dec-compatibleclns enable
Use the clns enable interface configuration command if you do not intend to perform any static or dynamic routing on an interface, but intend to pass ISO CLNS packet traffic to end systems. Use the no form of this command to disable ISO CLNS on a particular interface.
clns enable
no clns enableSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Example
The following example enables ISO CLNS on Ethernet interface 0:
interface ethernet 0clns enableclns erpdu-interval
Use the clns erpdu-interval interface configuration command to determine the minimum interval time, in milliseconds, between error PDUs (ERPDUs). A milliseconds value of zero or the no form of this command turns off the interval and effectively sets no limit between ERPDUs.
clns erpdu-interval milliseconds
no clns erpdu-interval millisecondsSyntax Description
Default
10 milliseconds
Command Mode
Interface configuration
Usage Guidelines
This command does not send ERPDUs more frequently than one per interface per 10 milliseconds. It is wise not to send an ERPDU frequently if bandwidth is precious, such as over slow serial lines.
Example
The following example sets the ERPDU interval to 30 milliseconds:
interface ethernet 0clns erpdu-interval 30Related Command
clns esct-time
Use the clns esct-time interface configuration command to supply an ES Configuration Timer (ESCT) option in a transmitted IS hello packet that tells the end system how often it should transmit ES hello packet protocol data units (PDUs). Use the no form of this command to restore the default value and disable this feature.
clns esct-time seconds
no clns esct-time secondsSyntax Description
Default
0 seconds (disabled)
Command Mode
Interface configuration
Example
The following example sets the ES configuration time to 10 seconds:
interface ethernet 0clns esct-time 10Related Commands
clns configuration-time
clns holding-timeclns es-neighbor
Use the clns es-neighbor interface configuration command to list all end systems that will be used when you manually specify the NSAP-to-SNPA mapping. The SNPAs are the MAC addresses. Use the no form of this command to delete the ES neighbor.
clns es-neighbor nsap snpa
no clns es-neighbor nsapSyntax Description
Default
No end systems are listed.
Command Mode
Interface configuration
Usage Guidelines
If you have configured either the clns router iso-igrp or clns router isis interface configuration commands for a particular interface, the ES-IS routing software automatically turns ES-IS on for that interface.
It is only necessary to use static mapping for those end systems that do not support ES-IS. The router will continue to discover dynamically those end systems that do support ES-IS.
Example
The following example defines an ES neighbor on Ethernet interface 0:
interface ethernet 0clns es-neighbor 47.0004.004D.0055.0000.0C00.A45B.00 0000.0C00.A45BIn this case, the end systems with the following NSAP (or NET) are configured with an Ethernet MAC address of 0000.0C00.A45B:
47.0004.004D.0055.0000.0C00.A45B.00Related Commands
clns filter-expr
Use one or more clns filter-expr global configuration commands to combine CLNS filter sets and CLNS address templates into complex logical NSAP pattern-matching expressions. The no form of this command deletes the expression. There are many forms of this command.
clns filter-expr ename term
clns filter-expr ename not term
clns filter-expr ename term or term
clns filter-expr ename term and term
clns filter-expr ename term xor term
no clns filter-expr enameSyntax Description
Default
No filter expression is defined.
Command Mode
Global configuration
Usage Guidelines
Filter expressions can reference previously defined filter expressions, so you can build arbitrarily complex expressions.
The first form listed defines a simple filter expression that is pattern matched only if the pattern given by term is matched.
The second form defines a filter expression that is pattern matched only if the pattern given by term is not matched.
The third form defines a filter expression that is pattern matched if either of the patterns given by the two terms are matched.
The fourth form defines a filter expression that is pattern matched only if both of the patterns given by the two terms are matched.
The fifth form defines a filter expression that is pattern matched only if one of the patterns, but not both, given by the two terms are matched.
The sixth and final form of the command deletes the definition of an existing filter expression.
Use this command to define complex filter expressions. See the description of the clns filter-set global configuration command to learn how to define filter sets.
Example
The following example shows how to define a filter expression that matches addresses with a source address of anything besides 39.840F, and a destination address that started with 47.0005 or 47.0023, but nothing else:
clns filter-set US-OR-NORDUNET permit 47.0005...clns filter-set US-OR-NORDUNET permit 47.0023clns filter-set NO-ANSI deny 38.840F...clns filter-set NO-ANSI permit defaultclns filter-expr STRANGE source NO-ANSI and destination US-OR-NORDUNETRelated Commands
clns filter-set
clns template-alias
show clns filter-exprclns filter-set
Use one or more clns filter-set global configuration commands to build a list of CLNS address templates with associated permit and deny conditions for use in CLNS filter expressions. CLNS filter expressions are used in the creation and use of CLNS access lists. The no form of this command deletes the entire filter set.
clns filter-set sname [permit | deny] template
no clns filter-set snameSyntax Description
Default
No address templates are defined.
Command Mode
Global configuration
Usage Guidelines
Use this command to define a list of pattern matches and permit/deny conditions for use in CLNS filter expressions. Filter expressions are used in the creation and use of CLNS access lists. See the description of the clns filter-expr global configuration command to learn how to define filter expressions and the clns template-alias global configuration command to learn how to define address templates and address template aliases.
Each address that must be matched against a filter set is first compared against all of the entries in the filter set, in order, for an exact match with the address. If the exact match search fails to find a match, then the entries in the filter set containing wildcard matches are scanned for a match, again, in order. The first template that matches is used. If an address does not match any of the filter set entries, an implicit "deny" is returned as the permit/deny action of the filter set.
Examples
The following example returns a permit action if an address starts with either 47.0005 or 47.0023. It returns an implicit deny action on any other address.
clns filter-set US-OR-NORDUNET permit 47.0005...clns filter-set US-OR-NORDUNET permit 47.0023...The following example returns a deny action if an address starts with 39.840F, but returns a permit action for any other address:
clns filter-set NO-ANSI deny 38.840F...clns filter-set NO-ANSI permit defaultRelated Commands
clns filter-expr
clns template-alias
show clns filter-setclns holding-time
Use the clns holding-time global configuration command to allow the sender of an ESH or ISH to specify the length of time you consider the information in the hello packets to be valid. You can restore the default value (300 seconds or 5 minutes) by using the no form of this command.
clns holding-time seconds
no clns holding-timeSyntax Description
seconds
Length of time in seconds during which the information in the hello packets is considered valid.
Default
300 seconds (5 minutes)
Command Mode
Global configuration
Usage Guidelines
Setting this value too high puts extra traffic on a line and adds time to process hellos. However, you want to avoid setting it too low if your topology changes more often than the router sends updates.
Example
The following example sets the holding time at 150 seconds:
clns holding-time 150Related Commands
clns configuration-time
clns esct-timeclns host
Use the clns host global configuration command to define a name-to-NSAP mapping that can then be used with commands requiring NSAPs.
clns host name nsap
Syntax Description
name
Desired name for the NSAP. The first character can be either a letter or a number, but if you use a number, the operations you can perform are limited.
nsap
NSAP that the name maps to.
Default
No mapping is defined.
Command Mode
Global configuration
Usage Guidelines
The assigned NSAP name is displayed, where applicable, in show and debug EXEC commands. There are some effects and requirements associated with using names to represent NETs and NSAPs, however. Although using names as proxies for addresses is allowed with CLNS commands, they are never written out to NVRAM.
The first character can be either a letter or a number, but if you use a number, the operations you can perform (such as ping) are limited.
The clns host command is generated after all other CLNS commands when the configuration file is parsed. As a result, the NVRAM version of the configuration cannot be edited to specifically change the address defined in the original clns host command. You must specifically change any commands that refer to the original address. This affects all commands that accept names.
The commands that are affected by these requirements include the following:
•
net (router configuration command)
•
•
•
Example
The following example defines names to NSAPs:
clns host cisco1 39.0001.0000.0c00.1111.00clns host cisco2 39.0002.0000.0c00.1111.00router iso-igrpnet cisco1!interface ethernet 0clns net cisco2Related Commands
clns es-neighbor
clns is-neighborclns is-neighbor
Use the clns is-neighbor interface configuration command to list all intermediate systems that will be used when you manually specify the NSAP-to-SNPA mapping. The SNPAs are the MAC addresses. Use the no form of this command to delete the specified IS neighbor.
clns is-neighbor nsap snpa
no clns is-neighbor nsapSyntax Description
nsap
NSAP of a specific intermediate system to enter as neighbor to a specific MAC address.
snpa
Data link (MAC) address.
Default
No intermediate systems are listed.
Command Mode
Interface configuration
Usage Guidelines
It is sometimes preferable for a router to have a neighbor entry statically configured rather than learned through ES-IS, ISO-IGRP, or IS-IS. This interface configuration command enters an IS neighbor.
Example
The following example defines an IS neighbor on Ethernet interface 0:
interface ethernet 0clns is-neighbor 47.0004.004D.0055.0000.0C00.A45B.00 0000.0C00.A45BRelated Commands
clns mtu
Use the clns mtu interface configuration command to set the MTU packet size for the interface. The no form of this command restores the default and maximum packet size.
clns mtu size
no clns mtuSyntax Description
size
Maximum packet size in bytes. The minimum value is 512; the default and maximum packet size depends on the interface type.
Default
Depends on interface type
Command Mode
Interface configuration
Usage Guidelines
All interfaces have a default maximum packet size. You can set the maximum transmission unit (MTU) size of the packets sent on the interface using this interface configuration command.
All devices on a physical medium must have the same protocol MTU in order to operate.
The CTR card does not support the switching of frames larger than 4472 bytes. Interoperability problems can occur if CTR cards are intermixed with other Token Ring cards on the same network. These problems can be minimized by lowering the CLNS maximum packet sizes (MTUs) to be the same on all devices on the network, using the clns mtu command.
Note
Example
The following example sets the MTU packet size to 1000 bytes:
interface ethernet 0clns mtu 1000Related Command
A dagger (†) indicates that the command is documented in another chapter.
mtu †
clns net (global configuration command)
Use the clns net global configuration command to assign a static address for a router. If a router is configured to support ISO CLNS but is not configured to dynamically route CLNS packets using ISO-IGRP or IS-IS, use this command to assign an address to the router. The no form of this command removes any previously configured NET or NSAP address.
clns net {net-address | name}
no clns net {net-address | name}Syntax Description
net-address
Network Entity Title (NET). Refer to the "Usage Guidelines" section.
name
CLNS host name to be associated with this interface.
Default
No static address is assigned.
Command Mode
Global configuration
Usage Guidelines
A CLNS packet sent to any of the defined NSAPs or NETs will be received by the router. The router chooses the NET to use when it sends a packet with the following algorithm:
•
•
•
Example
The following example assigns a static address:
clns net 49.0001.aa00.0400.9105.00clns net (interface configuration command)
Use the clns net command interface configuration command to assign an NSAP address or name to a router interface. If a router is configured to support ISO CLNS, but is not configured to dynamically route CLNS packets using an ISO-IGRP or IS-IS, use this command to assign an address to the router. The no form of this command removes any previously configured NSAP address.
clns net {nsap-address | name}
no clns net {nsap-address | name}Syntax Description
Default
No address or name is assigned.
Command Mode
Interface configuration
Usage Guidelines
This command is useful if you are doing static routing and need to control the source NET used by the router on each interface.
Examples
The following example assigns an NSAP address to a router interface:
interface ethernet 0clns net 49.0001.0000.0c00.1111.00The following example assigns a name to a router interface:
interface ethernet 0clns net ciscoclns packet-lifetime
Use the clns packet-lifetime global configuration command to specify the initial lifetime for locally generated packets. The no form of this command removes the parameter's settings.
clns packet-lifetime seconds
no clns packet-lifetimeSyntax Description
Default
32 seconds
Command Mode
Global configuration
Example
The following example sets a packet lifetime of 120 seconds:
clns packet-lifetime 120Related Command
clns rdpdu-interval
Use the clns rdpdu-interval interface configuration command to determine the minimum interval time, in milliseconds, between redirect PDUs (RDPDUs). A milliseconds value of zero or the no form of this command turns off the interval rate and effectively sets no limit between RDPDUs.
clns rdpdu-interval milliseconds
no clns rdpdu-interval millisecondsSyntax Description
Default
100 milliseconds
Command Mode
Interface configuration
Usage Guidelines
An RDPDU is rate-limited and is not sent more frequently than one per interface per 100 milliseconds. There is no need to change the default. This setting will work fine for most networks.
Example
The following example sets an interval of 50 milliseconds:
interface ethernet 0clns rdpdu-interval 50Related Command
clns route (interface static route)
Use this form of the clns route global configuration command to create an interface static route. The no form of this command removes this route.
clns route nsap-prefix type number [snpa-address]
no clns route nsap-prefixSyntax Description
Default
No interface static routes are created.
Command Mode
Global configuration
Usage Guidelines
If you do not specify an SNPA address when you have a multiaccess network, you will receive an error message indicating a bad SNPA.
Examples
The following example shows how to create a static route for an Ethernet interface:
clns route 39.0002 ethernet 3 aa00.0400.1111The following example shows how to create a static route for a serial interface:
clns route 39.0002 serial 0Related Commands
clns route (to enter a static route)
clns route default
clns route discardclns route (to enter a static route)
Use this form of the clns route global configuration command to enter a specific static route. NSAPs that start with nsap-prefix are forwarded to next-hop-net or the name of the next hop. The no form of this command removes this route.
clns route nsap-prefix {next-hop-net | name}
no clns route nsap-prefixSyntax Description
Default
No static route is entered.
Command Mode
Global configuration
Example
The following example forwards all packets toward the specified route:
clns route 39.840F 47.0005.80FF.FF00.0123.4567.89AB.00Related Commands
clns route (to enter a static route)
clns route default
clns route discardclns route default
Use the clns route global configuration command to configure a default zero-length prefix rather than type an NSAP prefix. The no form of this command removes this route.
clns route default nsap-prefix type number
no clns route defaultSyntax Description
Default
No default prefix is configured.
Command Mode
Global configuration
Example
The following example configures a default zero-length prefix:
clns route default 39.840F ethernet0Related Commands
clns route (interface static route)
clns route (to enter a static route)
clns route discardclns route discard
Use the clns route discard global configuration command to explicitly tell a router to discard packets with NSAP addresses that match the specified nsap-prefix. The no form of this command removes this route.
clns route nsap-prefix discard
no clns route nsap-prefixSyntax Description
Default
No NSAP addresses are identified.
Command Mode
Global configuration
Usage Guidelines
The decnet advertise command and the clns route discard command work together when DECnet Phase IV/V conversion is enabled. Any packet with the specified CLNS NSAP prefix causes CLNS to behave as if no route was found. Because DECnet Phase IV/V conversion is enabled, the route is then looked up in the Phase IV routing table. The router that is advertising the DECnet Phase IV route converts the packet to OSI and sends it to the router that is advertising the CLNS discard static route. Once it gets there, the packet is converted back to Phase IV.
Example
The following example discards packets with a destination NSAP address that matches the prefix 47.0005:
clns route 47.0005 discardRelated Commands
clns route (interface static route)
clns route (to enter a static route)
clns route defaultclns route-cache
Use the clns route-cache interface configuration command to allow fast switching through the cache. To disable fast switching, use the no form of this command.
clns route-cache
no clns route-cacheSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Interface configuration
Usage Guidelines
The cache still exists and is used after the no clns route-cache command is used; the software just does not do fast switching through the cache.
Example
The following example shows how to allow fast switching through the cache:
interface ethernet 0clns route-cacheclns router isis
Use the clns router isis interface configuration command to enable IS-IS routing for OSI on a specified interface. The no clns router isis command with the appropriate area tag disables IS-IS on the interface. Use the no form of this command with the appropriate area tag to disable IS-IS routing for the system.
clns router isis [tag]
no clns router isis [tag]Syntax Description
Default
IS-IS routing is not specified for any interface.
Command Mode
Interface configuration
Usage Guidelines
Creating a name for a routing process means that you use names when configuring routing. You can specify only one IS-IS process per router.
Example
The following example enables IS-IS routing for OSI on Ethernet interface 0:
router isis cisconet 39.0001.0000.0c00.1111.00interface ethernet 0clns router isis ciscoRelated Command
clns router iso-igrp
Use the clns router iso-igrp interface configuration command to specify ISO-IGRP routing on a specified interface. The no form of this command with the appropriate area tag disables ISO-IGRP on the interface. Use the no form of the global configuration command command with the appropriate tag to disable ISO-IGRP routing for the system.
clns router iso-igrp tag [level 2]
no clns router iso-igrp tagSyntax Description
Default
ISO-IGRP routing is not specified on any interface.
Command Mode
Interface configuration
Global configurationUsage Guidelines
If you want this interface to advertise Level 2 information only, use the level 2 keyword. This option reduces the amount of router-to-router traffic by telling the router to send out only Level 2 routing updates on certain interfaces. Level 1 information is not passed on the interfaces for which the Level 2 option is set.
Example
In the following example, the interface advertises Level 2 information only on serial interface 0:
router iso-igrp marketingnet 49.0001.0000.0c00.1111.00interface serial 0clns router iso-igrp marketing level 2Related Command
clns routing
Use the clns routing global configuration command to enable routing of CLNS packets. Use the no form of this command to disable CLNS routing.
clns routing
no clns routingSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Global configuration
Example
The following example enables routing of CLNS packets:
clns routingRelated Command
clns security pass-through
Use the clns security pass-through global configuration command to allow the router to pass packets that have security options set. Use the no form of this command to disable this function.
clns security pass-through
no clns security pass-throughSyntax Description
This command has no arguments or keywords.
Default
The router discards any packets it sees as set with security options.
Command Mode
Global configuration
Example
The following example allows the router to pass packets that have security options set:
clns routingrouter iso-igrpnet ...clns security pass-throughRelated Command
clns send-erpdu
Use the clns send-erpdu interface configuration command to allow CLNS to send an error PDU when the routing software detects an error in a data PDU. To disable this function, use the no form of this command.
clns send-erpdu
no clns send-erpduSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Interface configuration
Usage Guidelines
When a CLNS packet comes in, the routing software looks in the routing table for the next hop. If it does not find the next hop, the packet is discarded and an error protocol data unit (ERPDU) can be sent.
Example
The following example shows how to allow CLNS to send an error PDU when it detects an error in a data PDU:
interface ethernet 0clns send-erpduRelated Command
clns send-rdpdu
Use the clns send-rdpdu interface configuration command to allow CLNS to send redirect PDUs (RDPDUs) when a better route for a given host is known. To disable this function, use the no form of this command.
clns send-rdpdu
no clns send-rdpduSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Interface configuration
Usage Guidelines
If a packet is sent out the same interface it came in on, an RDPDU can also be sent to the sender of the packet.
Example
The following example shows how to allow CLNS to send redirect PDUs:
interface ethernet 0clns send-rdpduRelated Command
clns split-horizon
Use the clns split-horizon interface configuration command to implement split horizon for ISO-IGRP updates. The no form of this command disables this feature.
clns split-horizon
no clns split-horizonSyntax Description
This command has no arguments or keywords.
Default
For all LAN interfaces—enabled
For WAN interfaces on X.25, Frame Relay, or SMDS networks—disabledCommand Mode
Interface configuration
Usage Guidelines
Normally, routers that are connected to broadcast-type OSI networks and that use distance vector routing protocols employ the split-horizon mechanism to prevent routing loops. Split horizon blocks information about routes from being advertised by a router out any interface from which that information originated. This behavior usually optimizes communications among multiple routers, particularly when links are broken. However, with nonbroadcast networks, such as Frame Relay and SMDS, situations can arise for which this behavior is less than ideal. For all interfaces except those for which either Frame Relay or SMDS encapsulation is enabled, the default condition for this command is for split horizon to be enabled.
If your configuration includes either the encapsulation frame-relay or encapsulation smds interface configuration commands, the default is for split horizon to be disabled. Split horizon is not disabled by default for interfaces using any of the X.25 encapsulations.
For networks that include links over X.25 PSNs, the neighbor interface configuration command can be used to defeat the split horizon feature. You can as an alternative explicitly specify the no clns split-horizon command in your configuration. However, if you do so, you must similarly disable split horizon for all routers in any relevant multicast groups on that network.
Split horizon for ISO-IGRP defaults to off for X.25, SMDS, and Frame Relay. Thereby, destinations are advertised out the interface for which the router has a destination.
In general, changing the state of the default for this interface configuration command is not recommended, unless you are certain that your application requires making a change in order to properly advertise routes. Remember that if split horizon is disabled on a serial interface (and that interface is attached to a packet-switched network), you must disable split horizon for all routers in any relevant multicast groups on that network.
Example
In the following example, split horizon is disabled on a serial link connected to an X.25 network:
interface serial 0encapsulation x25no clns split-horizonclns template-alias
Use one or more clns template-alias global configuration commands to build a list of alphanumeric aliases of CLNS address templates for use in the definition of CLNS filter sets. The no form of this command deletes the alias.
clns template-alias name template
no clns template-alias nameSyntax Description
name
Alphanumeric name to apply as an alias for the template.
template
Address template, as defined in the "Usage Guidelines" section.
Default
No alias list is defined.
Command Mode
Global configuration
Usage Guidelines
Address templates are "pattern forms" that match one or more CLNS addresses. They can be simple single CLNS addresses, which match just themselves, or contain wildcards, prefixes, and suffixes, allowing a single template to match many addresses.
The simplest address template matches just a single address, as shown in this example:
47.0005.1234.5678.9abc.def0.00Wildcard digits, which can match any value, are indicated with asterisks (*). The following template matches the above address and any other 12-byte long address that starts with 47.0005.1234.5678:
47.0005.1234.5678.****.****.**Because OSI addresses are variable in length, it is often useful to build templates that match addresses that share a common prefix. The following template matches any address of any length that begins with the prefix 47.0005.1234.5678:
47.0005.1234.5678...In other instances, matching a suffix of the address is also important, such as when matching system IDs. The following template matches any address that ends with the suffix 0000.0c01.2345.00:
...0000.0c01.2345.00In other cases, you might want to match addresses on a single-bit granularity, rather than half-byte (four-bit, or nibble) granularity. This pattern matching is supported by allowing the hex digits that represent four bits to be replaced by groups of four binary bits, represented by 0s and 1s. These four binary digits are enclosed within parentheses.
