Table Of Contents
decnet route (interface static route)
decnet route (specific static route)
decnet route default (interface default route)
decnet route default (specific default route)
decnet out-routing-filter
To provide access control to routing information being sent out on an interface, use the decnet out-routing-filter command in interface configuration mode. To remove access control, use the no form of this command.
decnet out-routing-filter access-list-number
no decnet out-routing-filter
Syntax Description
access-list-number
Standard DECnet access list applying to source addresses. The value can be in the range 300 to 399.
Defaults
No access control to routing information is defined.
Command Modes
Interface configuration
Command History
Usage Guidelines
Addresses that fail this test are shown in the update message as unreachable.
Examples
The following example sets up Ethernet interface 1 with a DECnet out-routing filter of 351. This filter is applied to addresses in the transmitted routing updates. Transmitted hello messages are not filtered.
interface ethernet 1decnet out-routing-filter 351Related Commands
decnet path-split-mode
To specify how Cisco IOS software splits the routable packets between equal-cost paths, use the decnet path-split-mode command in global configuration mode.
decnet path-split-mode {normal | interim}
Syntax Description
Defaults
Normal mode
Command Modes
Global configuration
Command History
Examples
In the following example, a router will split routable packets between equal-cost paths using the round-robin (or first-come, first-served) basis:
decnet path-split-mode normalRelated Commands
decnet propagate static
To enable static route propagation, use the decnet propagate static command in global configuration mode. To disable propagation, use the no form of this command.
decnet propagate static
no decnet propagate static
Syntax Description
This command has no arguments or keywords.
Defaults
No default routes are propagated.
Command Modes
Global configuration
Command History
Usage Guidelines
By default, DECnet static routes are not propagated to other routers. Use the decnet propagate static command to enable static route propagation. A default route is used only after DECnet conversion is checked.
Examples
The following example enables static route propagation for the specified static and default routes:
decnet propagate static!decnet route 3.0 ethernet 0 aa00.0400.0404decnet route 5.0 serial 0decnet route 5.100 serial 2decnet route default 2.100decnet route 6.0 2.3 4 5Related Commands
Creates an interface static route.
Enters a specific static route.
Displays the global DECnet parameters.
Displays all statically configured DECnet routes.
decnet route (interface static route)
To create an interface static route, use this version of the decnet route command in global configuration mode. To remove this route, use the no form of this command.
decnet route decnet-address next-hop-type number [snpa-address] [hops [cost]]
no decnet route decnet-address next-hop-type number
Syntax Description
Defaults
hops: 0
cost: 0
No interface static routes are created.
Command Modes
Global configuration
Command History
Usage Guidelines
If you do not specify a Subnetwork Point of Attachment (SNPA) address when you have a multiaccess network, you receive an error message indicating a bad SNPA. By default, DECnet static routes are not propagated to other routers. Use the decnet propagate static command to enable propagation.
Examples
The following example creates a static route for a serial interface. No SNPA need be specified for point-to-point interfaces.
decnet route 3.1 serial 1The following example creates a static route for an Ethernet interface. The SNPA must be specified for an interface that is not point-to-point.
decnet route 3.2 ethernet 1 aa00.0400.0104Related Commands
decnet route (specific static route)
To enter a specific static route, use this version of the decnet route command in global configuration mode. DECnet addresses that match are forwarded to the next-hop-address. To remove this route, use the no form of this command.
decnet route decnet-address next-hop-address [hops [cost]]
no decnet route decnet-address next-hop-address
Syntax Description
Defaults
No interface static routes are created.
Command Modes
Global configuration
Command History
Usage Guidelines
Area static routes can be configured by specifying a DECnet node address of 0. By default, DECnet static routes are not propagated to other routers. Use the decnet propagate static command to enable propagation.
Examples
The following example creates a static route for 1.1 that points to 1.9 and uses default values of 0 for the hops and cost arguments:
decnet route 1.1 1.9The following example creates a static route for 3.100 that points to 3.4 and specifies values for the hops and cost:
decnet route 3.100 3.4 9 8The following example creates a static route for area 1 that points to 2.999:
decnet route 1.0 2.999Related Commands
decnet route default (interface default route)
To create an interface default route, use this version of the decnet route default command in global configuration mode. To remove this route, use the no form of this command.
decnet route default next-hop-type number [snpa-address] [hops [cost]]
no decnet route default next-hop-type number
Syntax Description
Defaults
No interface default routes are created.
Command Modes
Global configuration
Command History
Usage Guidelines
If you do not specify an SNPA address when you have a multiaccess network, you receive an error message indicating a bad SNPA.
A default route is used only after DECnet conversion is checked. DECnet default routes are not propagated to other routers.
Examples
The following example creates a default route for a serial interface. No SNPA need be specified for point-to-point interfaces.
decnet route default serial 1The following example creates a default route for an Ethernet interface. The SNPA must be specified for an interface that is not point-to-point.
decnet route default ethernet 1 aa00.0400.0104Related Commands
decnet route default (specific default route)
To enter a specific default route, use this version of the decnet route default command in global configuration mode. To remove this route, use the no form of this command.
decnet route default next-hop-address [hops [cost]]
no decnet route default next-hop-address
Syntax Description
Defaults
hops: 0
cost: 0
No interface default routes are created.
Command Modes
Global configuration
Command History
Usage Guidelines
A default route is used only after DECnet conversion is checked. By default, DECnet static routes are not propagated to other routers. Use the decnet propagate static command to enable propagation.
DECnet packets not for the current area are forwarded to the next-hop-address.
Examples
The following example creates a default route for 1.3, which uses default values of 0 for hops and cost:
decnet route default 1.3Related Commands
decnet route-cache
To enable fast switching, use the decnet route-cache command in interface configuration mode. To disable fast switching, use the no form of this command.
decnet route-cache
no decnet route-cache
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Interface configuration
Command History
Usage Guidelines
By default, Cisco's DECnet routing software implements fast switching of DECnet datagrams. There are times when it makes sense to disable fast switching. This is especially important when using rates slower than T1.
Fast switching uses memory space on interface cards. In situations where a high-bandwidth interface is writing large amounts of information to a low-bandwidth interface, additional memory could help avoid congestion on the slow interface.
On a Cisco router that has DECnet traffic passing through a GRE tunnel interface and the decnet route-cache command enabled, loss of connectivity over the tunnel may occur after a tunnel key is configured on the tunnel interface. If this occurs, enter the no decnet route-cache command on the tunnel interface, followed by the decnet route-cache command to clear the problem.
Examples
The following example disables fast switching on Ethernet interface 0:
interface ethernet 0no decnet route-cachedecnet router-priority
To elect a designated router to which packets are sent when no destination is specified, use the decnet router-priority command in interface configuration mode.
decnet router-priority value
Syntax Description
value
Priority of the router. This can be a number in the range 0 to 127. The larger the number the higher the priority.
Defaults
64
Command Modes
Interface configuration
Command History
Usage Guidelines
The designated router is the router to which all end nodes on an Ethernet communicate if they do not know where else to send a packet. The designated router is chosen through an election process in which the router with the highest priority gets the job. When two or more routers on a single Ethernet in a single area share the same highest priority, the unit with the highest node number is elected. You can reset a router's priority to help ensure that it is elected designated router in its area.
On a LAN with both DECnet IV and DECnet IV Prime hosts, make sure that a bilingual router always becomes the designated router.
DECnet end systems use the designated router only when they have no other information about how to reach a particular system. The end systems maintain a cache of how to reach other systems on the network. The cache contains the following information:
<remote system DECnet address> <next hop DECnet address>When an end system receives a packet, it examines three pieces of information: the intra-LAN bit, the source address, and the previous hop. If the intra-LAN bit is set, indicating that the packet has never left this wire (and, thus, the remote system is reachable without a router), a cache entry is created as follows:
<remote system DECnet address> = <source address><next hop DECnet address> = <source address>If the intra-LAN bit is not set, indicating that the packet has come from another network, the cache entry is created as follows:
<remote system DECnet address> = <source address><next hop DECnet address> = <previous hop>If there is no cache entry, then the designated router is used. This means that when starting a session, the designated router is used, but the reverse traffic will populate a cache entry so that the router can later communicate directly.
A DECnet IV Prime end node sends a packet to the Unknown Destination multicast if it has no cache entry for the destination and has no designated router.
Examples
The following example sets DECnet priority for this router to 110 on Ethernet interface 1:
interface ethernet 1decnet router-priority 110decnet routing
To enable DECnet routing, use the decnet routing command in global configuration mode. To disable DECnet routing, use the no form of this command.
decnet [network-number] routing [iv-prime] decnet-address
no decnet routing
Syntax Description
Defaults
Disabled
Command Modes
Global configuration
Command History
Usage Guidelines
Enabling DECnet changes the MAC addresses of the router's interfaces. This is not a problem on routers equipped with nonvolatile memory. On systems that attempt to get their IP network addresses from network servers rather than from nonvolatile memory, there may be a problem as with the hardware addresses changing and confusing other IP-speaking hosts. This potential problem can be avoided by configuring and enabling DECnet before enabling other protocols.
Note
You can configure up to four DECnet networks (numbered 0 to 3). To set up multiple DECnet networks, use the decnet global configuration commands with the appropriate network number and keywords. If the network number is omitted from the commands, network 0 is configured for DECnet routing.
DECnet Phase IV Prime eliminates the DEC addressing restrictions so that DECnet nodes can coexist with systems running other protocols that have other MAC address restrictions. If iv-prime is not specified, only Phase IV is enabled; configuring the MAC address will then make DECnet inoperable. The standard "AA-00-04-00" form will be set as the address of the interface on which DECnet is enabled. If Phase IV Prime was already running and this command is reissued without the iv-prime keyword (that is, going from Phase IV Prime to Phase IV), the command returns an error if any of the interfaces that have DECnet enabled have MAC addresses that are not compliant with DECnet Phase IV, requiring the user to evaluate conflicting interface commands.
The no form of this command disables Phase IV and Phase IV Prime routing.
Examples
The following example enables DECnet routing for the router in area 21 with node number 456:
decnet routing 21.456Related Commands
decnet cost
Sets a cost value for an interface.
decnet node-type
Specifies the node type.
decnet routing-timer
To specify how often Cisco IOS software sends routing updates that list the hosts that the router can reach, use the decnet routing-timer command in interface configuration mode. To disable the routing update timer, use the no form of this command.
decnet routing-timer seconds
no decnet routing-timer
Syntax Description
Defaults
40 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
Other routers use this information to construct local routing tables. In a network where changes occur infrequently or do not need to be responded to immediately (it is small and uncomplicated, applications are not particularly sensitive to delays or occasional packet loss, slow serial links, and so on), increasing the time between routing updates reduces the amount of unnecessary network traffic. Digital calls this argument the broadcast routing timer because they use a different timer for serial lines; Cisco's DECnet implementation does not make this distinction.
Examples
The following example sets a serial interface to broadcast routing updates every 2 minutes (120 seconds):
interface serial 0decnet routing-timer 120decnet split-horizon
To use split horizon when sending routing updates, use the decnet split-horizon command in interface configuration mode. To disable split horizon, use the no form of this command.
decnet split-horizon
no decnet split-horizon
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Interface configuration
Command History
Usage Guidelines
The decnet split-horizon command also affects whether broadcast packets received on an interface are resent on the same interface.
The decnet split-horizon command determines how much information is included in routing updates sent out an interface. It also determines whether received broadcasts are retransmitted on the same interface. When you enable split horizon, routing updates sent out on a given interface will not include any information that was originally learned from that interface, and broadcasts will not be retransmitted on the receiving interface. This is because split horizon is designed for networks that are either broadcast networks, or are fully connected mesh networks. In these types of networks, resending this information is a waste of network bandwidth because all other stations on that network have already heard the information. Disabling split horizon causes Cisco IOS software to include all information in routing updates, and to resend broadcast packets on the network from which they were received.
You can use this command on any interface, but generally it makes sense to use it only for X.25 and Frame Relay interfaces. You should disable split horizon on X.25 and Frame Relay networks that are not fully connected mesh topologies.
Examples
The following example disables split horizon on an X.25 network:
interface serial 0no decnet split-horizonlat host-delay
To set the delayed acknowledgment for incoming local-area transport (LAT) slave connections, use the lat host-delay command in global configuration mode. To restore the default, use the no form of this command.
lat host-delay number
no host-delay
Syntax Description
Defaults
Disabled
Command Modes
Global configuration
Command History
Examples
The following example sets the acknowledgment for incoming LAT slave connections to 100 milliseconds:
lat host-delay 100lat service autocommand
To associate a command with a service, use the lat service autocommand command in global configuration mode. To remove the specified autocommand, use the no form of this command.
lat service service-name autocommand command
no lat service service-name autocommand command
Syntax Description
Defaults
No commands are automatically associated with a service.
Command Modes
Global configuration
Command History
Usage Guidelines
When an inbound connection is received for the specified service, the command associated with the service is automatically executed instead of the user receiving a virtual terminal session.
Authentication is bypassed for these services; only the LAT password is checked.
Note
Examples
The following example associates the command telnet ramana to the service RAMANA:
lat service RAMANA autocommand telnet ramanashow decnet
To display the global DECnet parameters, use the show decnet command in privileged EXEC mode.
show decnet
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Examples
The following is sample output from the show decnet command:
Router# show decnetGlobal DECnet parameters for network 0:Local address is 19.15, node type is area (Phase-IV Prime)Level-2 `Attached' flag is FALSE, nearest level-2 router is 19.5Maximum node is 350, maximum area is 63, maximum visits is 63Maximum paths is 1, path split mode is normalLocal maximum cost is 1022, maximum hops is 30Area maximum cost is 1022, maximum hops is 30Static routes *NOT* being sent in routing updatesDefault route configured; next hop address of 2.100Table 22 describes significant fields shown in the display.
show decnet accounting
To display the active accounting or checkpointed database, use the show decnet accounting command in EXEC mode.
show decnet accounting [checkpoint]
Syntax Description
Command Modes
EXEC
Command History
Examples
This sample output from the show decnet accounting command shows accounting data collected for traffic passing between the DECnet address pair 27.100 and 27.107:
Router# show decnet accountingSource Destination Bytes Packets27.100 27.107 145 527.107 27.100 500 5Accounting data age is 5Table 23 describes the fields shown in the display.
Related Commands
show decnet interface
To display the global DECnet status and configuration for all interfaces, or the status and configuration for a specified interface, use the show decnet interface command in EXEC mode.
show decnet interface [type number]
Syntax Description
Command Modes
EXEC
Command History
Examples
The following is sample output from the show decnet interface command:
Router# show decnet interfaceGlobal DECnet parameters for network 0:Local address is 19.15, node type is areaMaximum node is 350, maximum area is 63, maximum visits is 63Maximum paths is 1, path split mode is normalLocal maximum cost is 1022, maximum hops is 30Area maximum cost is 1022, maximum hops is 30Ethernet 1 is up, line protocol is up, encapsulation is ARPAInterface cost is 4, priority is 64, DECnet network: 0The designated router is 1.9Sending HELLOs every 15 seconds, routing updates 40 secondsSmallest router blocksize seen is 1498 bytesRouting input list is not set, output list is not setAccess list is not setDECnet fast switching is enabledNumber of L1 router adjacencies is: 3Number of non-PhaseIV+ router adjacencies is: 3Number of PhaseIV+ router adjacencies is: 0Router is bilingualTable 24 describes significant fields shown in the display.
The following is sample output from the show decnet interface command when you specify an interface:
Router# show decnet interface ethernet 0Ethernet0 is up, line protocol is up, encapsulation is ARPAInterface cost is 4, priority is 64, DECnet network: 0The designated router is 1.3Sending HELLOs every 15 seconds, routing updates 40 secondsSmallest router blocksize seen is 1498 bytesRouting input list is not set, output list is not setAccess list is not setDECnet fast switching is enabledNumber of L1 router adjacencies is: 1Number of non-PhaseIV+ router adjacencies is: 3Number of PhaseIV+ router adjacencies is: 0Router is bilingualTable 25 describes significant fields shown in the display.
show decnet map
To display the address mapping information used by the DECnet Address Translation Gateway, use the show decnet map command in EXEC mode.
show decnet map
Syntax Description
This command has no arguments or keywords.
Command Modes
EXEC
Command History
Examples
The following is sample output from the show decnet map command:
Router# show decnet mapNet Node -> Net Node Uses Cost Hops0 1.100 1 2.100 0Table 26 describes significant fields shown in the display.
show decnet neighbors
To display all Phase IV and Phase IV Prime adjacencies and the MAC address associated with each neighbor, use the show decnet neighbors command in privileged EXEC mode.
show decnet neighbors
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Examples
The following is sample output from the show decnet neighbors command:
Router# show decnet neighborsNet Node Interface MAC address Flags0 3.11 Ethernet0 aa00.0400.0b0c A0 1.1 Ethernet0 aa00.0400.0104 V0 1.3 Ethernet1 aa00.0400.0304 V0 1.6 Ethernet1 aa00.0400.0604 V0 2.2 TokenRing 5500.2000.4020 V IV-PRIMETable 27 describes the fields shown in the display.
show decnet route
To display the DECnet routing table, use the show decnet route command in EXEC mode.
show decnet route [decnet-address]
Syntax Description
decnet-address
(Optional) Displays the DECnet address and, when specified, the first hop route to that address.
Command Modes
EXEC
Command History
Examples
The following is sample output from the show decnet route command when a DECnet address name is not specified, so the entire routing table is displayed:
Router# show decnet routeArea Cost Hops Next Hop to Node Expires Prio1 4 1 Ethernet1 -> 1.300 26 64 A*1 4 1 Ethernet1 -> 1.400 37 64 A*2 8 2 Ethernet1 -> 1.400*5 0 0 (Local) -> 5.5*10 4 1 Ethernet2 -> 10.1 36 64 A*13 11 3 Ethernet1 -> 1.400*44 22 6 Ethernet1 -> 1.400*51 18 4 Ethernet1 -> 1.400*61 1 1 (OSI) -> 5.5*62 1 1 (OSI) -> 5.5*3 0 0 (STATIC) Ethernet0, snpa aa00.0400.0404*4 0 0 (STATIC) Serial0*6 5 4 (STATIC) forwarding to 2.3Node Cost Hops Next Hop to Node Expires Prio*(Area) 0 0 (Local) -> 5.5*5.5 0 0 (Local) -> 5.5 32 64 A+*DEFAULT*: 0 0 using next hop address of 2.100As the display shows, the show decnet route command can display more than one route for a destination when equal-cost paths have been set with the decnet max-paths global configuration command and when there is more than one equal-cost path to a destination. The display also shows that this node is an area router.
Table 28 describes significant fields shown in the display.
show decnet static
To display all statically configured DECnet routes, use the show decnet static command in privileged EXEC mode.
show decnet static
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
All static routes are stored in a static route queue, which allows static routes to be reinstated when DECnet routing is turned off then on again.
Not all routes in the static route queue will show up in the routing table. This happens under the following conditions:
•
–
decnet route 2.0 1.2–
decnet route 3.10 1.200–
decnet route 1.1 1.200•
–
decnet route 4.1 10.200–
decnet route 4.0 10.200–
decnet route 2.0 10.200–
decnet route 2.1 5.4Examples
The following is sample output from the show decnet static command:
Router# show decnet staticAddress Cost Hops Next hop SNPA3 0 0 Ethernet0 aa00.0400.04045 0 0 Serial05.100 0 0 Serial2DEFAULT 0 0 2.1006 5 4 2.3Note that this router is a Level 2 router with a DECnet address of 1.2, so a static route configured for 5.100 is not relevant here. This route appears in the show decnet static command display, but not in the routing table.
show decnet traffic
To show the DECnet traffic statistics (including datagrams sent, received, and forwarded), use the show decnet traffic command in EXEC mode.
show decnet traffic
Syntax Description
This command has no arguments or keywords.
Command Modes
EXEC
Command History
Examples
The following is sample output from the show decnet traffic command:
Router# show decnet trafficTotal: 42 received, 0 format errors, 0 unimplemented0 not a gateway, 0 no memory, 0 no routing vector0 congestion encounteredHellos: 21 received, 0 bad, 0 other area, 16 sentLevel 1 routing: 14 received, 0 bad, 0 other area, 16 sentLevel 2 routing: 7 received, 0 not primary router, 8 sentData: 0 received, 0 not long format, 0 too many visits0 forwarded, 0 returned, 0 converted, 0 local destination0 access control failed, 0 no route, 0 encapsulation failed0 inactive network, 0 incomplete mapTable 29 describes the fields shown in the display.
