DHCP Server is not Sending Gateway and DNS IP Addresses in DHCP Offer Packet
Resolution
Overview
The DHCP server is not sending gateway and DNS IP addresses in the DHCP offer packet.
Issue
A DHCP server configured with reserved IP addresses only is not sending gateway nor is it sending DNS IP addresses in the DHCP Offer Packet. If a DHCP server is configured on a Palo Alto Networks firewall with reserved IP addresses only, the firewall will not send gateway and DNS IP address in the DHCP offer packet.
The DHCP configuration looks like this:
dhcp {
interface {
ethernet1/4 {
server {
option {
dns {
primary 8.8.8.8;
}
lease {
unlimited;
}
gateway 172.16.70.70;
}
reserved {
172.16.70.100 {
mac 00:50:56:9E:64:96;
}
}
mode enabled;
}
}
}
}
The DHCP offer packet looks like this:
Workaround
Create a dummy IP pool like the following:
dhcp {
interface {
ethernet1/4 {
server {
option {
dns {
primary 8.8.8.8;
}
lease {
unlimited;
}
gateway 172.16.70.70;
}
reserved {
172.16.70.100 {
mac 00:50:56:9E:64:96;
}
}
mode enabled;
ip-pool 1.1.1.0/24;
}
}
}
}
The DHCP offer packet shows this:
owner: npoprzen