To set the rate at which a specified IP Service Level Agreements (SLAs) operation repeats, use the
frequency (IP SLA) command in the appropriate submode of IP SLA configuration or IP SLA monitor configuration mode. To return to the
default value, use the
no form of this command.
frequency seconds
no frequency
Syntax Description
seconds
|
Number of seconds between the IP SLAs operations. The default is 60.
|
Command Default
60 seconds
Command Modes
IP SLA Configuration
DHCP configuration (config-ip-sla-dhcp)
DLSw configuration (config-ip-sla-dlsw)
DNS configuration (config-ip-sla-dns)
Ethernet echo (config-ip-sla-ethernet-echo)
Ethernet jitter (config-ip-sla-ethernet-jitter)
FTP configuration (config-ip-sla-ftp)
HTTP configuration (config-ip-sla-http)
ICMP echo configuration (config-ip-sla-echo)
ICMP jitter configuration (config-ip-sla-icmpjitter)
ICMP path echo configuration (config-ip-sla-pathEcho)
ICMP path jitter configuration (config-ip-sla-pathJitter)
Multicast UDP jitter configuration (config-ip-sla-multicast-jitter-oper)
TCP connect configuration (config-ip-sla-tcp)
UDP echo configuration (config-ip-sla-udp)
UDP jitter configuration (config-ip-sla-jitter)
VCCV configuration (config-sla-vccv)
VoIP configuration (config-ip-sla-voip)
IP SLA Monitor Configuration
DHCP configuration (config-sla-monitor-dhcp)
DLSw configuration (config-sla-monitor-dlsw)
DNS configuration (config-sla-monitor-dns)
FTP configuration (config-sla-monitor-ftp)
HTTP configuration (config-sla-monitor-http)
ICMP echo configuration (config-sla-monitor-echo)
ICMP path echo configuration (config-sla-monitor-pathEcho)
ICMP path jitter configuration (config-sla-monitor-pathJitter)
TCP connect configuration (config-sla-monitor-tcp)
UDP echo configuration (config-sla-monitor-udp)
UDP jitter configuration (config-sla-monitor-jitter)
VoIP configuration (config-sla-monitor-voip)
Command History
Release
|
Modification
|
11.2
|
This command was introduced.
|
12.2(33)SRA
|
This command was integrated into Cisco IOS Release 12.2(33)SRA.
|
12.2(33)SRB
|
The Ethernet echo and Ethernet jitter configuration modes were added.
|
12.2SX
|
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends
on your feature set, platform, and platform hardware.
|
12.2(33)SRC
|
The VCCV configuration mode was added.
|
12.2(33)SB
|
The following configuration modes were added:
-
Ethernet echo
-
Ethernet jitter
-
VCCV
|
12.4(20)T
|
The Ethernet echo and Ethernet jitter configuration modes were added.
|
12.2(33)SXI
|
The Ethernet echo and Ethernet jitter configuration modes were added.
|
15.2(4)M
|
This command was modified. The multicast UDP jitter configuration mode was added.
|
Usage Guidelines
A single IP SLAs operation will repeat at a given frequency for the lifetime of the operation. For example, a User Datagram
Protocol (UDP) jitter operation with a frequency of 60 sends a collection of data packets (simulated network traffic) once
every 60 seconds, for the lifetime of the operation. The default simulated traffic for a UDP jitter operation consists of
ten packets sent 20 milliseconds apart. This “payload” is sent when the operation is started, then is sent again 60 seconds
later.
If an individual IP SLAs operation takes longer to execute than the specified frequency value, a statistics counter called
“busy” is incremented rather than immediately repeating the operation.
Consider the following guidelines before configuring the
frequency (IP SLA),
timeout (IP SLA), and
threshold (IP SLA) commands. For the IP SLAs UDP jitter operation, the following guidelines are recommended:
where N = (num-packets number-of-packets ) * (interval interpacket-interval ). Use the
udp-jitter command to configure the
num-packets number-of-packets and
interval interpacket-interval values.
For all other IP SLAs operations, the following configuration guideline is recommended:
(frequency seconds ) > (timeout milliseconds ) > (threshold milliseconds )
Note |
We recommend that you do not set the frequency value to less than 60 seconds because the potential overhead from numerous
active operations could significantly affect network performance.
|
The
frequency (IP SLA) command is supported in IPv4 networks. This command is also supported in IPv6 networks when configuring an IP SLAs
operation that supports IPv6 addresses.
IP SLAs Operation Configuration Dependence on Cisco IOS Release
The Cisco IOS command used to begin configuration for an IP SLAs operation varies depending on the Cisco IOS release you
are running (see the table below). You must configure the type of IP SLAs operation (such as User Datagram Protocol [UDP]
jitter or Internet Control Message Protocol [ICMP] echo) before you can configure any of the other parameters of the operation.
The configuration mode for the
frequency (IP SLA) command varies depending on the Cisco IOS release you are running (see the table below) and the operation type configured.
For example, if you are running Cisco IOS Release 12.4 and the ICMP echo operation type is configured, you would enter the
frequency (IP SLA) command in ICMP echo configuration mode (config-sla-monitor-echo) within IP SLA monitor configuration mode.
Table 10. Command Used to Begin Configuration of an IP SLAs Operation Based on Cisco IOS Release
Cisco IOS Release
|
Global Configuration Command
|
Command Mode Entered
|
12.4(4)T, 12.0(32)SY, 12.2(33)SRB, 12.2(33)SB, 12.2(33)SXI , or later releases
|
ip
sla
|
IP SLA configuration
|
12.3(14)T, 12.4, 12.4(2)T, 12.2(31)SB2, or 12.2(33)SXH
|
ip
sla
monitor
|
IP SLA monitor configuration
|
Examples
The following examples show how to configure an IP SLAs ICMP echo operation (operation 10) to repeat every 90 seconds. Note
that the Cisco IOS command used to begin configuration for an IP SLAs operation varies depending on the Cisco IOS release
you are running (see the table above).
Examples
This example shows the
frequency (IP SLA) command being used in an IPv4 network in ICMP echo configuration mode within IP SLA configuration mode:
ip sla 10
icmp-echo 172.16.1.175
frequency 90
!
ip sla schedule 10 life 300 start-time after 00:05:00
Examples
This example shows the frequency (IP SLA) command being used in an IPv4 network in ICMP echo configuration mode within IP
SLA monitor configuration mode:
ip sla monitor 10
type echo protocol ipIcmpEcho 172.16.1.175
frequency 90
!
ip sla monitor schedule 10 life 300 start-time after 00:05:00