D-Link DI-1750 Reference Manual page 192

(21)rtp Rtp parameters
(22)tcp Tcp parameters
(23)unnumbered Enable IP processing without an explicit address
(24)unreachables Enable sending ICMP Unreachable messages
Please Input the code of command to be excute(0-24):24
Input 24，Select unreachables option.
2. Sending ICMP Redirect Messages
Routes sometimes can become less than optimal. For example, it is possible for the router to be forced
to resend a packet through the same interface on which it was received. If this happens, the router
sends an ICMP Redirect message to the packet's originator telling it that it is on a subnet directly
connected to the router, and that it must forward the packet to another system on the same subnet. It
does so because the originating host presumably could have sent that packet to the next hop without
involving the router at all. The Redirect message instructs the sender to remove the router from the
route and substitute a specified device representing a more direct path.
This feature is enabled by default. However, when Hot Standby Router Protocol is configured on an
interface, ICMP Redirect messages are disabled by default for the interface.
You can enable the sending of ICMP Redirect messages by performing the following task in interface
configuration mode:
Ip redirects
In the prompt select ip option ，it will list all arguments.
Key Word:
U(undo) D(default) Q(quit)
......
(16)proxy-arp Enable proxy ARP
(17)redirects Enable sending ICMP Redirect messages
(18)rip set RIP parameter for this port
(19)route-cache Enable fast-switching cache for outgoing packets
(20)rsvp RSVP interface command
(21)rtp Rtp parameters
(22)tcp Tcp parameters
(23)unnumbered Enable IP processing without an explicit address
(24)unreachables Enable sending ICMP Unreachable messages
Please Input the code of command to be excute(0-24):17
input 17，Select redirects option .
3. Enable ICMP Mask Reply Messages
Occasionally, the host server must know the subnet mask. To achieve this information, the host server
can send ICMP Mask Request messages. These messages are responded to by ICMP Mask Reply
messages from router that have the requested information. By default, the router will send ICMP Mask
Request messages.
To enable the sending of ICMP Mask Reply messages, use the following command in interface
configuration mode:
ip mask-reply
In the prompt Select ip option ，it will list all arguments.
Key Word:
U(undo) D(default) Q(quit)
(00)access-group Specify access control for packets
(01)address IP address
Command
Command
Model Name
Function
Allow the sending of ICMP Redirect messages.
Function
Enable the sending of ICMP Mask Reply messages.
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