Table Of Contents
Quality of Service Commands
Use the commands in this chapter to configure quality of service (QoS), a measure of performance for a transmission system that reflects its transmission quality and service availability. The commands are arranged alphabetically.
For QoS configuration information and examples, refer to the Quality of Service Solutions Configuration Guide.
access-list rate-limit
To configure an access list for use with committed access rate (CAR) policies, use the access-list rate-limit global configuration command. To remove the access list from the configuration, use the no form of this command.
access-list rate-limit acl-index {precedence | mac-address | mask prec-mask}
no access-list rate-limit acl-index {precedence | mac-address | mask prec-mask}
Syntax Description
Defaults
No CAR access lists are configured.
Command Modes
Global configuration
Command History
Usage Guidelines
This command classifies packets by the specified IP precedence or MAC address for a particular CAR access list. You can then apply CAR policies, using the rate-limit command, to individual rate limit access lists. Thus, packets with different IP precedences or MAC addresses are treated differently by the CAR process.
You can specify only one command for each rate-limit access list. If you enter this command multiple times with the same access list number, the new command will overwrite the previous command.
Use the mask keyword to assign multiple IP precedences to the same rate-limit list. To determine the mask value, perform the following steps:
Step 1
Decide which precedences you want to assign to this rate-limit access list.
Step 2
Step 3
Step 4
A mask of FF matches any precedence, and 00 does not match any precedence.
Examples
The following example assigns any packets with a MAC address of 00e0.34b0.7777 to rate-limit access list 100:
router(config)# access-list rate-limit 100 00e0.34b0.7777The following example assigns packets with an IP precedence of 0, 1, or 2 to the rate-limit access list 25:
router(config)# access-list rate-limit 25 mask 07Related Commands
show access-lists rate-limit
Displays information about rate-limit access lists.
show ip cef
Displays entries in the FIB that are unresolved or displays a FIB summary.
bgp-policy
To enable Policy Propagation via Border Gateway Protocol (BGP) on the interface, use the bgp-policy interface configuration command. To disable Policy Propagation via BGP, use the no form of this command.
bgp-policy ip-prec-map
no bgp-policy ip-prec-map
Syntax Description
Defaults
Policy Propagation via BGP is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
For the Policy Propagation via BGP feature to work, you must enable BGP and CEF/DCEF. In addition, the proper route-map configuration must be in place to specify the IP precedence (for example, set ip precedence route-map configuration command).
Note
To display QoS policy information for the interface, use the show ip interface command.
Examples
The following example enables Policy Propagation via BGP on an interface based on the source address and the IP precedence setting:
router# configure terminalrouter(config)# interface ethernet 4/0/0router(config-if)# bgp-policy ip-prec-maprouter(config-if)# endrouter#clear ip rsvp reservation
To remove Resource Reservation Protocol (RSVP) RESV-related receiver information currently in the database, use the clear ip rsvp reservation command in EXEC mode.
clear ip rsvp reservation {session-ip-address sender-ip-address {tcp | udp | ip-protocol} session-dport sender-sport | *}
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
Use the clear ip rsvp reservation command to remove the RESV-related sender information currently in the database so that when reservation requests arrive, based on the RSVP admission policy, the relevant ones can be reestablished.
Whenever you change the clockrate or bandwidth of an interface, RSVP does not update its database to reflect the change. This is because such a change requires that RSVP reestablish reservations based on the new clockrate or bandwidth value and arbitrarily dropping some reservations while retaining others is not desired. The solution is to clear the RESV state by issuing the clear ip rsvp reservation command.
The clear ip rsvp reservation command clears the RESV state from the router on which you issued the command and causes the router to send a PATH TEAR message to the upstream routers thereby clearing the RESV state for that reservation on all the upstream routers.
Examples
The following example clears all the RESV-related receiver information currently in the database:
Router# clear ip rsvp reservation *
The following example clears all the RESV-related receiver information for a specified reservation currently in the database:
Router# clear ip rsvp reservation 10.2.1.1 10.1.1.2 udp 10 20
Related Commands
clear ip rsvp sender
Removes RSVP PATH-related sender information currently in the database.
clear ip rsvp sender
To remove Resource Reservation Protocol (RSVP) PATH-related sender information currently in the database, use the clear ip rsvp sender command in EXEC mode.
clear ip rsvp sender {session-ip-address sender-ip-address {tcp | udp | ip-protocol} session-dport sender-sport | *}
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
Use the clear ip rsvp sender command to remove the PATH-related sender information currently in the database so that when reservation requests arrive, based on the RSVP admission policy, the relevant ones can be reestablished.
Whenever you change the clockrate or bandwidth of an interface, RSVP does not update its database to reflect the change. This is because such a change requires that RSVP reestablish reservations based on the new clockrate or bandwidth value and arbitrarily dropping some reservations while retaining others is not desired. The solution is to clear the PATH state by issuing the clear ip rsvp sender command.
The clear ip rsvp sender command clears the PATH state from the router on which you issued the command and causes the router to send a PATH TEAR message to the downstream routers thereby clearing the PATH state for that reservation on all the downstream routers.
Examples
The following example clears all the PATH-related sender information currently in the database:
Router# clear ip rsvp sender *
The following example clears all the PATH-related sender information for a specified reservation currently in the database:
Router# clear ip rsvp sender 10.2.1.1 10.1.1.2 udp 10 20
Related Commands
clear ip rsvp reservation
Removes RSVP RESV-related receiver information currently in the database.
custom-queue-list
To assign a custom queue list to an interface, use the custom-queue-list interface configuration command. To remove a specific list or all list assignments, use the no form of this command.
custom-queue-list list
no custom-queue-list [list]
Syntax Description
Defaults
No custom queue list is assigned.
Command Modes
Interface configuration
Command History
Usage Guidelines
Only one queue list can be assigned per interface. Use this command in place of the priority-list command (not in addition to it). Custom queueing allows a fairness not provided with priority queueing. With custom queueing, you can control the interface's available bandwidth when it is unable to accommodate the aggregate traffic enqueued. Associated with each output queue is a configurable byte count, which specifies how many bytes of data should be delivered from the current queue by the system before the system moves on to the next queue. When a particular queue is being processed, packets are sent until the number of bytes sent exceeds the queue byte count or until the queue is empty.
Use the show queueing custom and show interfaces commands to display the current status of the custom output queues.
Examples
In the following example, custom queue list number 3 is assigned to serial interface 0:
router(config)# interface serial 0router(config-if)# custom-queue-list 3Related Commands
fair-queue
To enable weighted fair queueing (WFQ) for an interface, use the fair-queue interface configuration command. To disable weighted fair queueing for an interface, use the no form of this command.
fair-queue [congestive-discard-threshold [dynamic-queues [reservable-queues]]]
no fair-queue
Syntax Description
Defaults
Fair queueing is enabled by default for physical interfaces whose bandwidth is less than or equal to 2.048 Mbps and that do not use the following: X.25 and Synchronous Data Link Control (SDLC) encapsulations; Link Access Procedure, Balanced (LAPB); tunnels; loopbacks; dialer; bridges; or virtual interfaces. Fair queueing is not an option for these protocols. However, if custom queueing or priority queueing is enabled for a qualifying link, it overrides fair queueing, effectively disabling it. Additionally, fair queueing is automatically disabled if you enable the autonomous or silicon switching engine mechanisms.
Note
Command Modes
Interface configuration
Command History
Usage Guidelines
This command enables WFQ. With WFQ, packets are classified by flow. For example, packets with the same source IP address, destination IP address, source TCP or UDP port, destination TCP or UDP port, and protocol belong to the same flow; see Table 373 for a full list of protocols and traffic stream discrimination fields.
When enabled for an interface, WFQ provides traffic priority management that automatically sorts among individual traffic streams without requiring that you first define access lists. Enabling WFQ requires use of this command only.
When WFQ is enabled for an interface, new messages for high-bandwidth traffic streams are discarded after the configured or default congestive discard threshold has been met. However, low-bandwidth conversations, which include control message conversations, continue to enqueue data. As a result, the fair queue may occasionally contain more messages than its configured threshold number specifies.
WFQ uses a traffic data stream discrimination registry service to determine which traffic stream a message belongs to. For each forwarding protocol, Table 373 shows the attributes of a message that are used to classify traffic into data streams.
It is important to note that IP precedence, congestion in Frame Relay switching, and discard eligibility flags affect the weights used for queueing.
IP precedence, which is set by the host or by policy maps, is a number in the range of 0 to 7. Data streams of precedence number are weighted so that they are given an effective bit rate of number+1 times as fast as a data stream of precedence 0, which is normal.
In Frame Relay switching, message flags for forward explicit congestion notification (FECN), backward explicit congestion notification (BECN), and discard eligibility (DE) message flags cause the algorithm to select weights that effectively impose reduced queue priority, providing the application with "slow down" feedback and sorting traffic, giving the best service to applications within their committed information rate (CIR).
Fair queueing is supported for all LAN and line (WAN) protocols except X.25, including LAPB and SDLC; see the notes in the section "Default." Because tunnels are software interfaces that are themselves routed over physical interfaces, fair queueing is not supported for tunnels. Fair queueing is on by default for interfaces with bandwidth less than or equal to 2 Mbps.
Note
When Resource Reservation Protocol (RSVP) is configured on an interface that supports fair queueing or on an interface that is configured for fair queueing with the reservable queues set to 0 (the default), the reservable queue size is automatically configured using the following method: interface bandwidth divided by 32 kbps. You can override this default by specifying a reservable queue other than 0. For more information on RSVP, refer to the chapter "Configuring RSVP" in the Network Protocols Configuration Guide, Part 1.
Examples
The following example enables use of WFQ on serial interface 0, with a congestive threshold of 300. This threshold means that messages will be discarded from the queueing system only when 300 or more messages have been queued and the message is in a data stream that has more than one message in the queue. The transmit queue limit is set to 2, based on the 384-kilobit (Kb) line set by the bandwidth command:
router(config)# interface serial 0router(config-if)# bandwidth 384router(config-if)# fair-queue 300Unspecified parameters take the default values.
The following example requests a fair queue with a congestive discard threshold of 64 messages,
512 dynamic queues, and 18 RSVP queues:router(config)# interface Serial 3/0router(config-if)# ip unnumbered Ethernet 0/0router(config-if)# fair-queue 64 512 18Related Commands
fair-queue (DWFQ)
To enable distributed weighted fair queueing (DWFQ), use the fair-queue interface configuration command. The command enables DWFQ on an interface using a VIP2-40 or greater interface processor. To disable DWFQ, use the no form of this command.
fair-queue
no fair-queue
Syntax Description
This command has no arguments or keywords.
Defaults
DWFQ is enabled by default for physical interfaces whose bandwidth is less than or equal to
2.048 Mbps.DWFQ can be configured on interfaces but not subinterfaces. It is not supported on Fast EtherChannel, tunnel, or other logical or virtual interfaces such as Multilink Point-to-Point Protocol.
Table 374 lists the default queue lengths and thresholds.
Table 374 Default Fair Queues and Thresholds
Congestive discard threshold
64 messages
Dynamic queues
256
Reservable queues
0
Command Modes
Interface configuration
Command History
Usage Guidelines
With DWFQ, packets are classified by flow. Packets with the same source IP address, destination IP address, source TCP or UDP port, destination TCP or UDP port, and protocol belong to the same flow.
DWFQ allocates an equal share of the bandwidth to each flow.
Examples
The following example enables DWFQ on the HSSI 0/0/0 interface:
router(config)# interface Hssi0/0/0router(config-if)# description 45Mbps to R2router(config-if)# ip address 200.200.14.250 255.255.255.252router(config-if)# fair-queueRelated Commands
ip rsvp bandwidth
To enable RSVP for IP on an interface, use the ip rsvp bandwidth interface configuration command. To disable RSVP, use the no form of this command.
ip rsvp bandwidth [interface-kbps [single-flow-kbps]]
no ip rsvp bandwidth [interface-kbps [single-flow-kbps]]
Syntax Description
Defaults
RSVP is disabled by default. If the ip rsvp bandwidth command is entered but no bandwidth values are supplied (for example, ip rsvp bandwidth is entered followed by a carriage return, or pressing the Return or Enter key), a default bandwidth value is assumed for both the interface-kbps and single-flow-kbps arguments.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is not supported on VIP-based routers. RSVP is disabled by default to allow backward compatibility with systems that do not implement RSVP. Weighted Random Early Detection (WRED) or fair queueing must be enabled first.
Examples
The following example shows a T1 (1536 kbps) link configured to permit RSVP reservation of up to 1158 kbps, but no more than 100 kbps for any given flow on serial interface 0. Fair queueing is configured with 15 reservable queues to support those reserved flows, should they be required.
router(config)# interface serial 0router(config-if)# fair-queue 64 256 15router(config-if)# ip rsvp bandwidth 1158 100Related Commands
ip rsvp neighbors
To enable neighbors to request a reservation, use the ip rsvp neighbors interface configuration command. To disable this feature, use the no form of this command.
ip rsvp neighbors access-list-number
no ip rsvp neighbors access-list-number
Syntax Description
access-list-number
Number of a standard or extended access list. It can be any number from 1 to 199.
Defaults
The router accepts messages from any neighbor.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is not supported on VIP-based routers. Use this command to allow only specific RSVP neighbors to make a reservation. If no limits are specified, any neighbor can request a reservation. If an access list is specified, only neighbors meeting the specified access list requirements can make a reservation.
Examples
The following example allows neighbors meeting access list 1 requirements to request a reservation:
router(config)# interface ethernet 0router(config-if)# ip rsvp neighbors 1Related Commands
ip rsvp reservation
To enable a router to generate an RSVP RESV message, use the ip rsvp reservation global configuration command. To disable this feature, use the no form of this command.
ip rsvp reservation session-ip-address sender-ip-address {tcp | udp | ip-protocol} session-dport sender-sport next-hop-ip-address next-hop-interface {ff | se | wf} {rate | load} bandwidth burst-size
no ip rsvp reservation session-ip-address sender-ip-address {tcp | udp | ip-protocol} session-dport sender-sport next-hop-ip-address next-hop-interface {ff | se | wf} {rate | load} bandwidth burst-size
Syntax Description
Defaults
The router does not simulate receiving an RSVP RESV message by default.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to force the router to act like it is generating RSVP RESV messages from the receiver.
This command is not supported on VIP-based routers.
Examples
The following example specifies the use of a Shared Explicit Filter style of reservation and the Controlled Load Service, with token buckets of 100 or 150 kbps and 60 or 65 kbps maximum queue depth:
router(config)# interface ethernet 0router(config-if)# ip rsvp reservation 224.250.0.2 132.240.1.1 UDP 20 30 132.240.4.1 Et1 se load 100 60router(config-if)# ip rsvp reservation 224.250.0.2 132.240.2.1 TCP 20 30 132.240.4.1 Et1 se load 150 65The following example specifies the use of a Wild Card Filter style of reservation and the Guaranteed Bit Rate Service, with token buckets of 300 or 350 kbps and 60 or 65 kbps maximum queue depth:
router(config)# interface ethernet 0router(config-if)# ip rsvp reservation 224.250.0.3 0.0.0.0 UDP 20 0 132.240.4.1 Et1 wf rate 300 60router(config-if)# ip rsvp reservation 224.250.0.3 0.0.0.0 UDP 20 0 132.240.4.1 Et1 wf rate 350 65Note that the Wild Card Filter does not admit the specification of the sender; it accepts all senders. This action is denoted by setting the source address and port to zero. If, in any filter style, the destination port is specified to be zero, RSVP does not permit the source port to be anything else; it understands that such protocols do not use ports or that the specification applies to all ports.
Related Commands
ip rsvp sender
To enable a router to generate an RSVP PATH message, use the ip rsvp reservation global configuration command. To disable this feature, use the no form of this command.
ip rsvp sender session-ip-address sender-ip-address {tcp | udp | ip-protocol} session-dport
sender-sport previous-hop-ip-address previous-hop-interface bandwidth burst-sizeno ip rsvp sender session-ip-address sender-ip-address {tcp | udp | ip-protocol} session-dport
sender-sport previous-hop-ip-address previous-hop-interface bandwidth burst-sizeSyntax Description
Defaults
The router does not simulate RSVP PATH message generation by default.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to force the router to act like it is receiving RSVP PATH messages from the sender.
This command is not supported on VIP-based routers.
Examples
The following example sets up the router to act like it is receiving RSVP PATH messages using UDP over the loopback 1 interface:
router(config)# interface ethernet 0router(config-if)# ip rsvp sender 224.250.0.1 132.240.2.1 udp 20 30 132.240.2.1 loopback 1 50 5router(config-if)# ip rsvp sender 224.250.0.2 132.240.2.1 udp 20 30 132.240.2.1 loopback 1 50 5router(config-if)# ip rsvp sender 224.250.0.2 132.240.2.28 udp 20 30 132.240.2.28 loopback 1 50 5Related Commands
ip rsvp udp-multicast
To instruct the router to generate UDP-encapsulated RSVP multicasts whenever it generates an IP-encapsulated multicast packet, use the ip rsvp udp-multicast interface configuration command. To disable this feature, use the no form of this command.
ip rsvp udp-multicast [multicast-address]
no ip rsvp udp-multicast [multicast-address]
Syntax Description
Defaults
The generation of UDP multicasts is disabled. If a system sends a UDP-encapsulated RSVP message to the router, the router begins using UDP for contact with the neighboring system. The router uses multicast address 224.0.0.14 and starts sending to UDP port 1699. If the command is entered without specifying a multicast address, the router uses the same multicast address.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to instruct a router to generate UDP-encapsulated RSVP multicasts whenever it generates an IP-encapsulated multicast packet. Some hosts require this trigger from the router.
Examples
The following example reserves up to 7500 kbps on Ethernet interface 2, with up to 1 Mbps per flow. The router is configured to use UDP encapsulation with the multicast address 224.0.0.14.
router(config)# interface ethernet 2router(config-if)# ip rsvp bandwidth 7500 1000router(config-if)# ip rsvp udp-multicast 224.0.0.14Related Commands
priority-group
To assign the specified priority list to an interface, use the priority-group interface configuration command. To remove the specified priority group assignment, use the no form of this command.
priority-group list-number
no priority-group list-number
Syntax Description
Defaults
This command is disabled by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
Only one list can be assigned per interface. Priority output queueing provides a mechanism to prioritize packets transmitted on an interface.
Use the show queueing priority and show interfaces commands to display the current status of the output queues.
Examples
The following example causes packets for transmission on serial interface 0 to be classified by priority list 1:
router(config)# interface serial 0router(config-if)# priority-group 1The following example shows how to establish queueing priorities based on the address of the serial link on a STUN connection. Note that you must use the priority-group interface configuration command to assign a priority group to an output interface.
stun peer-name 131.108.254.6stun protocol-group 1 sdlc!interface serial 0! Disable the ip address for interface serial 0:no ip address! Enable the interface for STUN:encapsulation stun!stun group 2stun route address 10 tcp 131.108.254.8 local-ack priority!! Assign priority group 1 to the input side of interface serial 0:priority-group 1! Assign a low priority to priority list 1 on serial link identified! by group 2 and address A7:priority-list 1 stun low address 2 A7Related Commands
priority-list default
To assign a priority queue for those packets that do not match any other rule in the priority list, use the priority-list default global configuration command. To return to the default or assign normal as the default, use the no form of this command.
priority-list list-number default {high | medium | normal | low}
no priority-list list-number
Syntax Description
list-number
Any number from 1 to 16 that identifies the priority list.
high | medium | normal | low
Priority queue level. The normal queue is used, if you use the no form of this command.
Defaults
This command is not enabled by default.
Command Modes
Global configuration
Command History
Usage Guidelines
When you use multiple rules, remember that the system reads the priority settings in order of appearance. When classifying a packet, the system searches the list of rules specified by priority-list commands for a matching protocol or interface type. When a match is found, the system assigns the packet to the appropriate queue. The system searches the list in the order it is specified, and the first matching rule terminates the search.
Examples
The following example sets the priority queue for those packets that do not match any other rule in the priority list to a low priority:
router(config)# priority-list 1 default lowRelated Commands
priority-list interface
To establish queueing priorities on packets entering from a given interface, use the priority-list interface global configuration command. To remove an entry from the list, use the no form of this command with the appropriate arguments.
priority-list list-number interface interface-type interface-number {high | medium | normal | low}
no priority-list list-number
Syntax Description
Defaults
No queueing priorities are established by default.
Command Modes
Global configuration
Command History
Usage Guidelines
When you use multiple rules, remember that the system reads the priority settings in order of appearance. When classifying a packet, the system searches the list of rules specified by priority-list commands for a matching protocol or interface type. When a match is found, the system assigns the packet to the appropriate queue. The system searches the list in the order it is specified, and the first matching rule terminates the search.
Examples
The following example assigns a list entering on serial interface 0 to a medium priority queue level:
router(config)# priority-list 3 interface serial 0 medium
Note
Related Commands
priority-list protocol
To establish queueing priorities based upon the protocol type, use the priority-list protocol global configuration command. To remove a priority list entry assigned by protocol type, use the no form of this command followed by the appropriate list-number argument and the protocol keyword.
priority-list list-number protocol protocol-name {high | medium | normal | low} queue-keyword keyword-value
no priority-list list-number protocol [protocol-name {high | medium | normal | low} queue-keyword keyword-value]
Syntax Description
list-number
Any number from 1 to 16 that identifies the priority list selected by the user.
protocol-name
Protocol type: aarp, apollo, appletalk, arp, bridge (transparent), clns, clns_es, clns_is, compressedtcp, cmns, decnet, decnet_node, decnet_router-l1, decnet_router-l2, dlsw, ip, ipx, pad, rsrb, stun, vines, xns, and x25.
high | medium | normal | low
Priority queue level.
queue-keyword keyword-value
Possible keywords are fragments, gt, list, lt, tcp, and udp. See Table 375.
Defaults
No queueing priorities are established.
Command Modes
Global configuration
Command History
Usage Guidelines
When you use multiple rules for a single protocol, remember that the system reads the priority settings in order of appearance. When classifying a packet, the system searches the list of rules specified by priority-list commands for a matching protocol type. When a match is found, the system assigns the packet to the appropriate queue. The system searches the list in the order it is specified, and the first matching rule terminates the search.
The decnet_router-l1 keyword refers to the multicast address for all level 1 routers, which are intra-area routers, and the decnet_router-l2 keyword refers to all level 2 routers, which are interarea routers.
The dlsw, rsrb, and stun keywords refer only to direct encapsulation.
Use Table 375, Table 376, and Table 377 to configure the queueing priorities for your system.
Table 375 Protocol Priority Queue Keywords and Values
fragments
Assigns the priority level defined to fragmented IP packets (for use with the IP protocol only). More specifically, this command matches IP packets whose fragment offset field is nonzero. The initial fragment of a fragmented IP packet has a fragment offset of zero, so such packets are not matched by this command.
Note
gt byte-count
Specifies a greater-than count. The priority level assigned goes into effect when a packet size exceeds the value entered for the argument byte-count.
Note
list list-number
Assigns traffic priorities according to a specified list when used with AppleTalk, bridging, IP, IPX, VINES, or XNS. The argument list-number is the access list number as specified by the access-list global configuration command for the specified protocol-name. For example, if the protocol is AppleTalk, list-number should be a valid AppleTalk access list number.
lt byte-count
Specifies a less-than count. The priority level assigned goes into effect when a packet size is less than the value entered for the argument byte-count.
Note
tcp port
Assigns the priority level defined to TCP segments originating from or destined to a specified port (for use with the IP protocol only). Table 376 lists common TCP services and their port numbers.
udp port
Assigns the priority level defined to UDP packets originating from or destined to a specified port (for use with the IP protocol only). Table 377 lists common UDP services and their port numbers.
Table 376 Common TCP Services and Their Port Numbers
FTP data
20
FTP
21
SMTP
25
Telnet
23
Table 377 Common UDP Services and Their Port Numbers
DNS
53
NFS
2049
RPC
111
SNMP
161
TFTP
69
Note
For some protocols, such as TFTP and FTP, only the initial request uses port 69. Subsequent packets use a randomly chosen port number. For these types of protocols, the use of port numbers fails to be an effective method to manage queued traffic.Examples
The following example assigns 1 as the arbitrary priority list number, specifies DECnet as the protocol type, and assigns a high-priority level to the DECnet packets transmitted on this interface:
router(config)# priority-list 1 protocol decnet highThe following example assigns a medium-priority level to every DECnet packet with a size greater than 200 bytes:
router(config)# priority-list 2 protocol decnet medium gt 200The following example assigns a medium-priority level to every DECnet packet with a size less than 200 bytes:
router(config)# priority-list 4 protocol decnet medium lt 200The following example assigns a high-priority level to traffic that matches IP access list 10:
router(config)# priority-list 1 protocol ip high list 10The following example assigns a medium-priority level to Telnet packets:
router(config)# priority-list 4 protocol ip medium tcp 23The following example assigns a medium-priority level to UDP Domain Name Service packets:
router(config)# priority-list 4 protocol ip medium udp 53The following example assigns a high-priority level to traffic that matches Ethernet type code access list 201:
router(config)# priority-list 1 protocol bridge high list 201The following example assigns a high-priority level to DLSw+ traffic with TCP encapsulation:
router(config)# priority-list 1 protocol ip high tcp 2065The following example assigns a high-priority level to DLSw+ traffic with direct encapsulation:
router(config)# priority-list 1 protocol dlsw high
Note
Related Commands
priority-list queue-limit
To specify the maximum number of packets that can be waiting in each of the priority queues, use the priority-list queue-limit global configuration command. To select the normal queue, use the no form of this command.
priority-list list-number queue-limit [high-limit [medium-limit [normal-limit [low-limit]]]]
no priority-list list-number queue-limit
Syntax Description
list-number
Any number from 1 to 16 that identifies the priority list.
high-limit
medium-limit
normal-limit
low-limit(Optional) Priority queue maximum length. A value of 0 for any of the four arguments means that the queue can be of unlimited size for that particular queue.
For default values for these arguments, see Table 378.
Defaults
This command is not enabled by default.
Command Modes
Global configuration
Command History
Usage Guidelines
If a priority queue overflows, excess packets are discarded and quench messages can be sent, if appropriate, for the protocol.
The default queue limit arguments are listed in Table 378.
Table 378 Default Priority Queue Packet Limits
high-limit
20
medium-limit
40
normal-limit
60
low-limit
80
Note
Examples
The following example sets the maximum packets in the priority queue to 10:
router(config)# priority-list 2 queue-limit 10 40 60 80Related Commands
queue-list default
To assign a priority queue for those packets that do not match any other rule in the queue list, use the queue-list default global configuration command. To restore the default value, use the no form of this command.
queue-list list-number default queue-number
no queue-list list-number default queue-number
Syntax Description
list-number
Number of the queue list. Any number from 1 to 16.
queue-number
Number of the queue. Any number from 1 to 16. The default number of the queue list is queue number 1.
Defaults
This command is disabled by default.
Command Modes
Global configuration
Command History
Usage Guidelines
When you use multiple rules, remember that the system reads the queue-list commands in order of appearance. When classifying a packet, the system searches the list of rules specified by queue-list commands for a matching protocol or interface type. When a match is found, the system assigns the packet to the appropriate queue. The system searches the list in the order it is specified, and the first matching rule terminates the search.
Queue number 0 is a system queue. It is emptied before any of the other queues are processed. The system enqueues high-priority packets, such as keepalives, to this queue.
Use the show interfaces command to display the current status of the output queues.
Examples
In the following example, the default queue for list 10 is set to queue number 2:
router(config)# queue-list 10 default 2Related Commands
queue-list interface
To establish queueing priorities on packets entering on an interface, use the queue-list interface global configuration command. To remove an entry from the list, use the no form of this command.
queue-list list-number interface interface-type interface-number queue-number
no queue-list list-number interface interface-type interface-number queue-number
Syntax Description
Defaults
No queueing priorities are established.
Command Modes
Global configuration
Command History
Usage Guidelines
When you use multiple rules, remember that the system reads the queue-list commands in order of appearance. When classifying a packet, the system searches the list of rules specified by queue-list commands for a matching protocol or interface type. When a match is found, the system assigns the packet to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
Examples
In the following example, queue list 4 establishes queueing priorities for packets entering on interface tunnel 3. The queue number assigned is 10.
router(config)# queue-list 4 interface tunnel 3 10Related Commands
queue-list protocol
To establish queueing priority based upon the protocol type, use the queue-list protocol global configuration command. To remove an entry from the list, use the no form of this command with the appropriate list number.
queue-list list-number protocol protocol-name queue-number queue-keyword keyword-value
no queue-list list-number protocol protocol-name queue-number queue-keyword keyword-value
Syntax Description
list-number
Number of the queue list. Any number from 1 to 16.
protocol-name
Required argument that specifies the protocol type: aarp, apollo, appletalk, arp, bridge (transparent), clns, clns_es, clns_is, cmns, compressedtcp, decnet, decnet_node, decnet_routerl1, decnet_routerl2, dlsw, ip, ipx, pad, rsrb, stun, vines, xns, and x25.
queue-number
Number of the queue. Any number from 1 to 16.
queue-keyword keyword-value
Possible keywords are gt, list, lt, tcp, and udp. See Table 375.
Defaults
No queueing priorities are established.
Command Modes
Global configuration
Command History
Usage Guidelines
When you use multiple rules, remember that the system reads the queue-list commands in order of appearance. When classifying a packet, the system searches the list of rules specified by queue-list commands for a matching protocol or interface type. When a match is found, the packet is assigned to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
The decnet_router-l1 keyword refers to the multicast address for all level 1 routers, which are intra-area routers, and the decnet_router-l2 keyword refers to all level 2 routers, which are interarea routers.
The dlsw, rsrb, and stun keywords refer only to direct encapsulation.
Use Table 375, Table 376, and Table 377 from the priority-list protocol command to configure the queueing priorities for your system.
Examples
The following example assigns 1 as the custom queue list, specifies DECnet as the protocol type, and assigns 3 as a queue number to the packets transmitted on this interface:
router(config)# queue-list 1 protocol decnet 3The following example assigns DECnet packets with a size greater than 200 bytes to queue number 2:
router(config)# queue-list 2 protocol decnet 2 gt 200The following example assigns DECnet packets with a size less than 200 bytes to queue number 2:
router(config)# queue-list 4 protocol decnet 2 lt 200The following example assigns traffic that matches IP access list 10 to queue number 1:
router(config)# queue-list 1 protocol ip 1 list 10The following example assigns Telnet packets to queue number 2:
router(config)# queue-list 4 protocol ip 2 tcp 23The following example assigns UDP Domain Name Service packets to queue number 2:
router(config)# queue-list 4 protocol ip 2 udp 53The following example assigns traffic that matches Ethernet type code access list 201 to queue number 1:
router(config)# queue-list 1 protocol bridge 1 list 201Related Commands
queue-list queue byte-count
To specify how many bytes the system allows to be delivered from a given queue during a particular cycle, use the queue-list queue byte-count global configuration command. To return the byte count to the default value, use the no form of this command.
queue-list list-number queue queue-number byte-count byte-count-number
no queue-list list-number queue queue-number byte-count byte-count-number
Syntax Description
Defaults
This command is not enabled by default.
Command Modes
Global configuration
Command History
Examples
In the following example, queue list 9 establishes the byte count as 1400 for queue number 10:
router(config)# queue-list 9 queue 10 byte-count 1400Related Commands
queue-list queue limit
To designate the queue length limit for a queue, use the queue-list queue limit global configuration command. To return the queue length to the default value, use the no form of this command.
queue-list list-number queue queue-number limit limit-number
no queue-list list-number queue queue-number limit limit-number
Syntax Description
Defaults
This command is not enabled by default.
Command Modes
Global configuration
Command History
Examples
In the following example, the queue length of queue 10 is increased to 40:
router(config)# queue-list 5 queue 10 limit 40Related Commands
