Is there a way to exclude a single IP address from a DHCP pool? For various reasons I have a machine that I can't reconfigure or move off the network (let's call it a printer). It has been hard coded with address `x.x.x.50` and my DHCP pool is `x.x.x.10 -> x.x.x.246`.
I don't want to have two pool definitions for this one subnet just to cover the ranges on either side of this machine. Is there some form of 'exclude IP' argument/option?
I'm using Ubuntu 11 and the `isc-dhcp-server` package.
DISCLAIMER: I have googled and it only came up with IOS and Juniper configuration info.
Exclude IP address from DHCP pool
Re: Exclude IP address from DHCP pool
Why don't you set the IP for that appliance explicitly:
```
# The standard subnet
subnet 10.0.0.0 netmask 255.255.255.0 {
option domain-name "ourdomain.internal";
option routers 10.0.0.1;
option domain-name-servers 10.0.0.2;
range 10.0.0.10 10.0.0.49;
range 10.0.0.51 10.0.0.246;
}
#has hardcoded ip, and dhcp should not use that in pool
host fixedipappliance {
hardware ethernet 10:4e:ed:co:ff:ee;
fixed-address 10.0.0.50;
}
```
I just successfully tested a configuration with two ranges like that. Multiple range statements are legal, as per the manpage there must be *at least* one range statement:
>
The range statement
```
range [ dynamic-bootp ] low-address [ high-address];
```
For any subnet on which addresses will be assigned dynamically, there
must be at least one range statement. The range statement gives the
lowest and highest IP addresses in a range. All IP addresses in the
range should be in the subnet in which the range statement is declared.
The dynamic-bootp flag may be specified if addresses in the specified
range may be dynamically assigned to BOOTP clients as well as DHCP
clients. When specifying a single address, high-address can be omit‐
ted.
```
# The standard subnet
subnet 10.0.0.0 netmask 255.255.255.0 {
option domain-name "ourdomain.internal";
option routers 10.0.0.1;
option domain-name-servers 10.0.0.2;
range 10.0.0.10 10.0.0.49;
range 10.0.0.51 10.0.0.246;
}
#has hardcoded ip, and dhcp should not use that in pool
host fixedipappliance {
hardware ethernet 10:4e:ed:co:ff:ee;
fixed-address 10.0.0.50;
}
```
I just successfully tested a configuration with two ranges like that. Multiple range statements are legal, as per the manpage there must be *at least* one range statement:
>
The range statement
```
range [ dynamic-bootp ] low-address [ high-address];
```
For any subnet on which addresses will be assigned dynamically, there
must be at least one range statement. The range statement gives the
lowest and highest IP addresses in a range. All IP addresses in the
range should be in the subnet in which the range statement is declared.
The dynamic-bootp flag may be specified if addresses in the specified
range may be dynamically assigned to BOOTP clients as well as DHCP
clients. When specifying a single address, high-address can be omit‐
ted.