- IP SLAs Overview
- Configuring IP SLAs UDP Jitter Operations
- Configuring IP SLAs UDP Jitter Operations for VoIP
- Configuring IP SLAs UDP Echo Operations
- Configuring IP SLAs HTTP Operations
- Configuring IP SLAs TCP Connect Operations
- Configuring Cisco IP SLAs ICMP Jitter Operations
- Configuring IP SLAs ICMP Echo Operations
- Configuring IP SLAs ICMP Path Echo Operations
- Configuring IP SLAs ICMP Path Jitter Operations
- Configuring IP SLAs FTP Operations
- Configuring IP SLAs DNS Operations
- Configuring IP SLAs DHCP Operations
- Configuring an IP SLAs Multioperation Scheduler
- Configuring Proactive Threshold Monitoring for IP SLAs Operations
Configuring IP SLAs DHCP Operations
This module describes how to configure an IP Service Level Agreements (SLAs) Dynamic Host Control Protocol (DHCP) probe to measure the response time between a Cisco device and a DHCP server to obtain an IP address.
- Finding Feature Information
- Information About IP SLAs DHCP Operations
- How to Configure IP SLAs DHCP Operations
- Configuration Examples for IP SLAs DHCP Operations
- Additional References
- Feature Information for IP SLAs DHCP Probe
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Information About IP SLAs DHCP Operations
DHCP Operation
DHCP provides a mechanism for allocating IP addresses dynamically so that addresses can be reused when hosts no longer need them. The DHCP operation measures the round-trip time (RTT) taken to discover a DHCP server and obtain a leased IP address from it. IP SLAs releases the leased IP address after the operation.
You can use the RTT information to determine DHCP performance levels.
There are two modes for the DHCP operation. By default, the DHCP operation sends discovery packets on every available IP interface on the device. If a specific server is configured on the device, discovery packets are sent only to the specified DHCP server.
IP SLAs DHCP Relay Agent Options
A DHCP relay agent is any host that forwards DHCP packets between clients and servers. Relay agents are used to forward requests and replies between clients and servers when they are not on the same physical subnet. Relay agent forwarding is distinct from the normal forwarding of an IP device, where IP packets are switched between networks somewhat transparently. Relay agents receive DHCP messages and then generate a new DHCP message to send out on another interface.
The IP SLAs DHCP operation contains a relay agent information option--Option 82, which is inserted by the DHCP relay agent when forwarding client-originated DHCP packets to a DHCP server. Servers recognizing the relay agent information option may use the information to implement IP address or other parameter assignment policies. The DHCP server echoes the option back verbatim to the relay agent in server-to-client replies, and the relay agent strips the option before forwarding the reply to the client.
Option 82 includes three suboptions that convey information known by the relay agent:
How to Configure IP SLAs DHCP Operations
Note |
There is no need to configure an IP SLAs responder on the destination device. |
Configuring a DHCP Operation on the Source Device
Perform one of the following tasks:
Configuring a Basic DHCP Operation
1. enable
2. configure terminal
3. ip sla operation-number
4. dhcp {destination-ip-address | destination-hostname} [source-ip {ip-address | hostname}] [option-82 [circuit-id circuit-id] [remote-id remote-id] [subnet-mask subnet-mask]]
5. frequency seconds
6. end
DETAILED STEPS
Configuring a DHCP Operation with Optional Parameters
1. enable
2. configure terminal
3. ip sla operation-number
4. dhcp {destination-ip-address | destination-hostname} [source-ip {ip-address | hostname}] [option-82 [circuit-id circuit-id] [remote-id remote-id] [subnet-mask subnet-mask]]
5. history buckets-kept size
6. history distributions-of-statistics-kept size
7. history enhanced [interval seconds] [buckets number-of-buckets]
8. history filter {none | all | overThreshold | failures}
9. frequency seconds
10. history hours-of-statistics-kept hours
11. history lives-kept lives
12. owner owner-id
13. history statistics-distribution-interval milliseconds
14. tag text
15. threshold milliseconds
16. timeout milliseconds
17. end
DETAILED STEPS
Scheduling IP SLAs Operations
- All IP Service Level Agreements (SLAs) operations to be scheduled must be already configured.
- The frequency of all operations scheduled in a multioperation group must be the same.
- The list of one or more operation ID numbers to be added to a multioperation group must be limited to a maximum of 125 characters in length, including commas (,).
- ip sla schedule operation-number [life {forever | seconds}] [start-time {[hh:mm:ss] [month day | day month] | pending | now | after hh:mm:ss}] [ageout seconds] [recurring]
- ip sla group schedule group-operation-number operation-id-numbers {schedule-period schedule-period-range | schedule-together} [ageout seconds] [frequency group-operation-frequency] [life {forever | seconds}] [start-time {hh:mm [:ss] [month day | day month] | pending | now | after hh:mm [:ss]}]
1. enable
2. configure terminal
3. Enter one of the following commands:
4. end
5. show ip sla group schedule
6. show ip sla configuration
DETAILED STEPS
Troubleshooting Tips
- If the IP Service Level Agreements (SLAs) operation is not running and not generating statistics, add the verify-data command to the configuration (while configuring in IP SLA configuration mode) to enable data verification. When data verification is enabled, each operation response is checked for corruption. Use the verify-data command with caution during normal operations because it generates unnecessary overhead.
- Use the debug ip sla trace and debug ip sla error commands to help troubleshoot issues with an IP SLAs operation.
What to Do Next
To add proactive threshold conditions and reactive triggering for generating traps (or for starting another operation) to an IP Service Level Agreements (SLAs) operation, see the “Configuring Proactive Threshold Monitoring” section.
Configuration Examples for IP SLAs DHCP Operations
Example Configuration for an IP SLAs DHCP Operation
In the following example, IP SLAs operation number 12 is configured as a DHCP operation enabled for DHCP server 172.16.20.3. Note that DHCP option 82 is used to specify the circuit ID.
Device B Configuration
ip dhcp-server 172.16.20.3 ! ip sla 12 dhcp 10.10.10.3 option-82 circuit-id 10005A6F1234 frequency 30 timeout 5000 tag DHCP_Test ! ip sla schedule 12 start-time now
Additional References
Related Documents
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
Cisco IOS IP SLAs commands |
|
Cisco IOS IP SLAs: general information |
“Cisco IOS IP SLAs Overview” module of the Cisco IOS IP SLAs Configuration Guide. |
Multioperation scheduling for IP SLAs |
“Configuring Multioperation Scheduling of IP SLAs Operations” module of the Cisco IOS P SLAs Configuration Guide |
Proactive threshold monitoring for IP SLAs |
“Configuring Proactive Threshold Monitoring of IP SLAs Operations” module of the Cisco IOS IP SLAs Configuration Guide |
MIBs
MIBs |
MIBs Link |
---|---|
CISCO-RTTMON-MIB |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for IP SLAs DHCP Probe
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
---|---|---|
IP SLAs DHCP Probe |
Cisco IOS XE Release 3.2SE |
The IP SLAs Dynamic Host Control Protocol (DHCP) Probe feature allows you to schedule and measure the network response time between a Cisco device and a DHCP server to obtain an IP address. |