DHCP
DHCP is handled by isc-dhcp-server on sr66-hda at 10.2.2.10. All configuration for IPv4 DHCP is in /etc/dhcp/dhcpd.conf. IPv6 is currently unmanaged in the environment.
In the DHCP configuration, there are 5 /16 subnets which define gateways at “10.*.1.254” for each. The subnets for 4 and 5 each have a DHCP pool allotted as well.
Below that are groups representing a /24 subnot which have narrowly defined rules. Each device is given a static assignment via MAC address and a host name. Each group defines the gateway, DNS servers, subnet mask (255.255.0.0), and lease time. The file is well commented, and changes are made by editing this file manually and restarting the isc-dhcp-server service with the command “systemctl restart isc-dhcp-server”. Removed devices are preserved in comments at the bottom of this file.
In order for DHCP to work across the subnets, a helper IP needs to exist on each subnet (except 2, where the DHCP server natively lives). The DHCP relay is defined in the L3 switch sr66-prosafe-00 under “System → Routing → Bootp/DHCP Relay Agent”.