Configuring NTP Option with Two IP Addresses

Configuring NTP option with two IP addresses is a pool-specific option and will be offered to the clients in the pool as a configuration parameter.

To configure NTP option with two IP Addresses:

Create a pool and enter the DHCP Pool Configuration mode
iS5comm(config)# ip dhcp pool <pool number (1-2147483647)>

iS5comm(config)# ip dhcp pool 1

A pool number is entered. The range is from 1 to 2147483647.
Configure NTP Option with two IP addresses.
iS5comm(dhcp-config)# ntp-server <ip address> [<ip address>]

iS5comm(dhcp-config)# ntp-server 12.0.0.6 15.0.0.5

The NTP IP addresses are configured as 12.0.0.6 and 15.0.0.5. This is Option 42 as shown in RFC 2132.
Verify the assigned IP Addresses.
iS5comm(dhcp-config)# end

iS5comm# show ip dhcp server pools
```
Global Options
```
```
--------------
```
```
Code : 3, Value : 12.0.0.2
```
```
Pool Id : 1
```
```
-------------------------------------------
```
```
Subnet : 12.0.0.0
```
```
Subnet Mask : 255.0.0.0
```
```
Lease time : 95400 secs
```
```
Utilization threshold : 50%
```
```
Start Ip : 12.0.0.1
```
```
End Ip : 12.0.0.100
```
```
Subnet Options
```
```
--------------
```
```
Code : 42, Value : 12.0.0.6,15.0.0.5
```
Note: This option will be offered to the DHCP clients only when there is no Host specific option for the client. If this option is not configured and there is no Host option too, then the global option will be preferred.