DHCP (PI_DHCP)
- Organization of this page
Function
The DHCP (PI_DHCP) record stores information about DHCP service response time. This is a multi-instance record.
Default and changeable values
Item |
Default value |
Changeable |
---|---|---|
Collection Interval |
360 |
Y |
Collection Offset |
0 |
Y |
Log |
No |
Y |
LOGIF |
(Blank) |
Y |
Over 10 Sec Collection Time |
No |
N |
ODBC key fields
PI_DHCP_MSR_COND_ID
Lifetime
None
Record size
-
Fixed part: 681 bytes
-
Variable part: 220 bytes
Fields
View name (Manager name) |
Description |
Summary rule |
Format |
Delta |
Data source |
---|---|---|---|---|---|
Address Assignment Time (ADDR_ASSIGN_TIME) |
Address presentation time (seconds) ((2) in Figure 10-1) |
AVG |
double |
No |
Probe Daemon |
Address Reservation Time (ADDR_RESERV_TIME) |
Address acquisition time (seconds) ((3) in Figure 10-1) |
AVG |
double |
No |
Probe Daemon |
Total Amount of Data (TOTAL_DATA_SIZE) |
Total amount of data transferred between the DHCP probe and the monitored server on UDP (bytes) |
AVG |
double |
No |
Probe Daemon |
Total Response Time (TOTAL_RESP_TIME) |
Total response time (seconds) ((1) in Figure 10-1) |
AVG |
double |
No |
Probe Daemon |
The following figure shows the DHCP sequence.
DHCP operating environment and notes
A DHCP probe searches for the measurement-target DHCP server and measures the time required for dynamically acquiring the IP address.
The following describes and provides notes on a DHCP operating environment.
Acquisition of IP address
The DHCP probe broadcasts an address presentation request and receives an address presentation from the DHCP server. To accept the presented IP address, address acquisition as shown in Figure 10-1 is performed. If the presented IP address is not to be accepted, address acquisition is not performed.
The address presentation request, address acquisition request, and their responses are all sent by broadcasting.
Release of IP address
If IP address acquisition is successful, address release as shown in Figure 10-1 is performed. If the presented IP address is not to be accepted, or if acquisition fails, address release is not performed. The time required for this address release is not included in the total response time.
Port number of the probe
Specify the port number of the DHCP client that has been defined at the monitoring-target DHCP server. Do not define more than one measurement item with the same probe port number.
RFC compliance
-
RFC2131: Dynamic Host Configuration Protocol
-
RFC2132: DHCP Options and BOOTP Vendor Extensions
-
For the functions that are not compliance with RFCs and the restrictions, see the above notes.