Chapter 7: DHCP Configuration Guide74 SmartSwitch Router User Reference Manual6. Define the address pool for ‘scope2’.7. Create a superscope ‘super1’ that includes ‘scope1’.8. Include ‘scope2’ in the superscope ‘super1’.For clients on the secondary subnet, the default gateway is 10.2.1.1, which is also thesecondary address for the interface ‘clients’.Interacting with Relay AgentsFor clients that are not directly connected to the DHCP server, a relay agent (typically arouter) is needed to communicate between the client and the server. The relay agent isusually only needed during the initial leasing of an IP address. Once the client obtains anIP address and can connect to the network, the renewal of the lease is performed betweenthe client and server without the help of the relay agent.The default gateway for the client must be capable of reaching the SSR’s DHCP server.The SSR must also be capable of reaching the client’s network. The route must beconfigured (with static routes, for example) or learned (with RIP or OSPF, for example) sothat the DHCP server can reach the client.The following example shows a simple configuration to support clients across a relayagent.1. Create an interface ‘clients’ with the primary address 10.1.1.1.2. Define a static route to the 10.5.x.x. subnet using the gateway 10.1.7.10 which tells theDHCP server how to send packets to the client on the 10.5.x.x subnet.3. Define the network parameters for ‘scope1’ with the default gateway 10.5.1.1 (therelay agent for the client).dhcp scope2 define pool 10.2.1.40-10.2.1.50dhcp scope1 attach superscope super1dhcp scope2 attach superscope super1interface create ip clients address-mask 10.1.1.1/16 port et.3.3ip add route 10.5.0.0/16 gateway 10.1.7.10dhcp scope1 define parameters address-netmask 10.5.0.0/16 gateway10.5.1.1 dns-domain acme.com
