Dell PowerConnect 6248 User's Guide - Page 551

- Timed Out-The previous graceful restart timed out. - Topology Changed- The previous graceful restart terminated prematurely because of a topology change. If you change the Support Mode, click Submit to save your change. Click Refresh to redisplay the page with the latest values from the switch. Enabling the NSF OSPF Graceful Restart Using CLI Commands For information about the CLI command that performs this function, see the following chapter in the CLI Reference Guide: • OSPF Commands The following table summarizes the equivalent CLI commands for this feature. Table 9-19. NSF OSPF Graceful Restart Command CLI Command nsf nsf helper nsf helper strict-lsa-checking show ip ospf show ip ospf neighbor Description Enables non-stop forwarding. Enables helpful neighbor functionality for the OSPF protocol. Requires that an OSPF helpful neighbor exit helper mode whenever a topology change occurs. Displays information relevant to the OSPF router. This command displays information about OSPF neighbors. BOOTP/DHCP Relay Agent BootP/DHCP Relay Agent enables BootP/DHCP clients and servers to exchange BootP/DHCP messages across different subnets. The relay agent receives the requests from the clients, and checks the valid hops and giaddr fields. If the number of hops is greater than the configured, the agent assumes the packet is looped through the agents and discards the packet. If giaddr field is zero the agent must fill in this field with the IP address of the interface on which the request was received. The agent unicasts the valid packets to the next configured destination. The server responds with a unicast BOOTREPLY addressed to the relay agent closest to the client as indicated by giaddr field. Upon reception of the BOOTREPLY from the server, the agent forwards this reply as broadcast or unicast on the interface form where the BOOTREQUEST was arrived. This interface can be identified by giaddr field. T he PowerConnect 6200 Series DHCP component also supports DHCP relay agent options to identify the source circuit when customers are connected to the Internet with high-speed modem. The relay agent inserts these options when forwarding the request to the server and removes them when sending the reply to the clients. If an interface has more than one IP address, the relay agent should use the primary IP address configured as its relay agent IP address. Configuring Routing 551