D-Link DI-1750 Reference Manual page 191

6.6 Configure IP Service
6.6.1 About IP Service Configuration
This chapter describes how to configure optional IP services. For a complete description of the IP
services commands in this chapter, refer to the "IP Services Commands" chapter of the Network
Protocols Command Reference.
6.6.2 Service Task List
Configure the following IP optional service:
♦ Manage IP Connections
Filter IP Packets
♦ Configure the Hot Standby Router Protocol
♦ Configure Performance Parameters
♦ Configure IP over WANs
♦ Monitor and Maintain the IP Network
Remember that not all the tasks in these sections are required. The tasks you must perform will depend
on your network and your needs.
6.6.3 5.5.2 Manage IP Connection
The IP suite offers a number of services that control and manage IP connections. Many of these
services are provided by the Internet Control Message Protocol (ICMP). ICMP messages are sent by
routers to hosts or other routers when a problem is discovered with the Internet header. For detailed
information on ICMP, see RFC 792.
To configure IP services, complete the tasks in the following sections:
♦ Enable ICMP Protocol Unreachable Messages
♦ Enable ICMP Redirect Messages
♦ Enable ICMP Mask Reply Messages
♦ Understand Path MTU Discovery
♦ Set the IP MTU Packet Size
♦ Enable IP Source Routing
♦ Enalbe IP Fast Switching
Enable IP Fast Switching in Same Interface
1. Send an ICMP Host Unreachable Message
If the router receives a packet that it is unable to deliver to the ultimate destination because it knows of
no route to the destination address, it sends an ICMP Host Unreachable message to the source. This
feature is enabled by default.
You can enable this service by performing the following command in interface configuration mode:
ip unreachables
Select ip option in the prompt, it will list all arguments:
Key Word:
U(undo) D(default) Q(quit)
......
Command
Model Name
Function
Enable the sending of ICMP Protocol Unreachable
messages.
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