| Exam 300-101 | Question id=437 | Infrastructure Security |
A network engineer is configuring a routed interface to forward broadcasts of UDP 69, 53, and 49 to 172.20.14.225. Which command should be applied to the configuration to allow this?
| A. |
router(config-if)#ip helper-address 172.20.14.225 | |
| B. |
router(config-if)#udp helper-address 172.20.14.225 | |
| C. |
router(config-if)#ip udp helper-address 172.20.14.225 | |
| D. |
router(config-if)#ip helper-address 172.20.14.225 69 53 49 |
To let a router forward broadcast packet the command ip helper-address can be used. The broadcasts will be forwarded to the unicast address which is specified with the ip helper command.
ip helper-address ip address
When configuring the ip helper-address command, the following broadcast packets will be forwarded by the router by default:
TFTP — UDP port 69
Domain Name System (DNS) – UDP port 53
Time service — port 37
NetBIOS Name Server — port 137
NetBIOS Datagram Server — port 138
Bootstrap Protocol (BOOTP) — port 67
TACACS – UDP port 49