A TFTP server, a DNS server, and a TACACS server are residing in the 192.168.5.0/24 subnet. Their IP addresses are 192.168.5.2, 192.168.5.3, and 192.168.5.4, respectively.You would like to configure the routers to forward UDP broadcasts to these servers.

• 300-410 : All Parts

Explanation:
The only command required is ip helper-address 192.168.5.255. This command is a directed broadcast to the subnet on which the servers reside which will cause all servers to receive the broadcast. Each server will process only the packets aimed at the port on which they are listening.

It not necessary to specify any port numbers because the ip helper-address command will forward to the following ports by default:
NTP – port 37
TACACs – port 49
DNS – port 53
BootP – port 67
TFTP – port 69
NetBIOS Name server – port 137
NetBIOS Datagram server – port 138

While the following command set would work, it does not contain the least number of commands:

ip helper-address 192.168.5.2 69
ip helper-address 192.168.5.3 53
ip helper-address 192.168.5.4 49

It is not required to specify each server and its respective port number.

The following command set would also have the desired results, because port numbers are not required for the default services:

ip helper-address 192.168.5.2
ip helper-address 192.168.5.3
ip helper-address 192.168.5.4

However, this is not the least number of commands you can execute to achieve the solution.

The command ip helper-address 192.168.50 69 53 49 would not work because it is addressed to the network number of the subnet to which the servers are connected. To send to them all requires a directed broadcast.

Objective:
Infrastructure Services
Sub-Objective:
Configure and verify IPv4 and IPv6 DHCP