Refer to the exhibit. Which two statements are true? (Choose two)
A.
DHCPDISCOVER packets will reach the DHCP server.
supports VLSM
B.
The router will not forward DHCPDISCOVER packets because it has not been configured
to do so.
link-state routing protocol
C.
This configuration is applied to interface Fa0/1.
D IP destination address
R1(config-if)#ip helper-address 10.1.1.1
This command does forward eight common UDP service broadcasts by default.
• TIME, port 37
• TACACS, port 49
• DNS, port 53
• BOOTP/DHCP Server, port 67
• BOOTP/DHCP Client, port 68
• TFTP, port 69
• NetBIOS name service, port 137
• NetBIOS datagram service, port 138
That’s going to cover most scenarios where the ip helper-address command will be useful,
but what about those situations where the broadcast you need forwarded is not on this list?
You can use the ip forward-protocol command to add any UDP port number to the list. In
this particular case, ports 67 and 68 were not included, so the BOOTP packets will not be
sent to the DHCP server.
QUESTION 168
Intermediate system to intermediate system (IS-IS), is a protocol used by network devices
(routers) to determine the best way to forward datagrams through a packet-switched
network, a process called routing. Which three attributes are of the IS-IS routing protocol?
operation is similar to BGP
D.
DHCPDISCOVER packets will not reach the DHCP server because DHCPDISCOVER
packets are broadcasts.
supports two routing levels within an autonomous system
E.
DHCPDISCOVER packets will not reach the DHCP server because ports 67 and 68 have
not been explicitly allowed by the ip forward-protocol command.
F.
This configuration is applied to interface Fa0/0.
A.
DHCPDISCOVER packets will reach the DHCP server.
supports VLSM
B.
The router will not forward DHCPDISCOVER packets because it has not been configured
to do so.
link-state routing protocol
C.
This configuration is applied to interface Fa0/1.
D IP destination address
R1(config-if)#ip helper-address 10.1.1.1
This command does forward eight common UDP service broadcasts by default.
• TIME, port 37
• TACACS, port 49
• DNS, port 53
• BOOTP/DHCP Server, port 67
• BOOTP/DHCP Client, port 68
• TFTP, port 69
• NetBIOS name service, port 137
• NetBIOS datagram service, port 138
That’s going to cover most scenarios where the ip helper-address command will be useful,
but what about those situations where the broadcast you need forwarded is not on this list?
You can use the ip forward-protocol command to add any UDP port number to the list. In
this particular case, ports 67 and 68 were not included, so the BOOTP packets will not be
sent to the DHCP server.
QUESTION 168
Intermediate system to intermediate system (IS-IS), is a protocol used by network devices
(routers) to determine the best way to forward datagrams through a packet-switched
network, a process called routing. Which three attributes are of the IS-IS routing protocol?
operation is similar to BGP
A.
DHCPDISCOVER packets will reach the DHCP server.
supports VLSM
B.
The router will not forward DHCPDISCOVER packets because it has not been configured
to do so.
link-state routing protocol
C.
This configuration is applied to interface Fa0/1.
D IP destination address
R1(config-if)#ip helper-address 10.1.1.1
This command does forward eight common UDP service broadcasts by default.
• TIME, port 37
• TACACS, port 49
• DNS, port 53
• BOOTP/DHCP Server, port 67
• BOOTP/DHCP Client, port 68
• TFTP, port 69
• NetBIOS name service, port 137
• NetBIOS datagram service, port 138
That’s going to cover most scenarios where the ip helper-address command will be useful,
but what about those situations where the broadcast you need forwarded is not on this list?
You can use the ip forward-protocol command to add any UDP port number to the list. In
this particular case, ports 67 and 68 were not included, so the BOOTP packets will not be
sent to the DHCP server.
QUESTION 168
Intermediate system to intermediate system (IS-IS), is a protocol used by network devices
(routers) to determine the best way to forward datagrams through a packet-switched
network, a process called routing. Which three attributes are of the IS-IS routing protocol?
operation is similar to BGP
D.
DHCPDISCOVER packets will not reach the DHCP server because DHCPDISCOVER
packets are broadcasts.
supports two routing levels within an autonomous system
Explanation:
While routers accept and generate broadcasts, they do not forward them. This can be quite
a problem when a broadcast needs to get to a device such as a DHCP or TFTP server that’s
on one side of a router with other subnets on the other side.
If this PC attempts to locate a DNS server with a broadcast, the broadcast will be stopped by
the router and will never get to the DNS server. By configuring the ip helper-address
command on the router, UDP broadcasts such as this will be translated into a unicast by the
router, making the communication possible. The command should be configured on the
interface that will be receiving the broadcasts.
R1(config)#int e0
R1(config-if)#ip helper-address ?The point of this question is bacis knowledge of IS-IS.
IS-IS is a link-state routing protocol, it supports VLSM and CIDR, it supports classless
routing, IS-IS supports level-1 and level-2 within an autonomous system. So option A C and
D are correct.
incorrect
not router-by-router.
