A new virtual server was created for the marketing department. The server was installed on an existing
host machine. Users in the marketing department report that they are unable to connect to the server.
Technicians verify that the server has an IP address in the same VLAN as the marketing department users.
Which of the following is the MOST likely reason the users are unable to connect to the server?
A.
The new virtual server’s MAC address was not added to the ACL on the switch
B.
The new virtual server’s MAC address triggered a port security violation on the switch
C.
The new virtual server’s MAC address triggered an implicit deny in the switch
D.
The new virtual server’s MAC address was not added to the firewall rules on the switch
Explanation:
Configuring the switch to allow only traffic from computers based upon their physical address is known as
MAC filtering. The physical address is known as the MAC address. Every network adapter has a unique
MAC address hardcoded into the adapter.
You can configure the ports of a switch to allow connections from computers with specific MAC addresses
only and block all other MAC addresses.
In computer networking, MAC Filtering (or GUI filtering, or layer 2 address filtering) refers to a security
access control method whereby the 48-bit address assigned to each network card is used to determine
access to the network.
MAC addresses are uniquely assigned to each card, so using MAC filtering on a network permits and
denies network access to specific devices through the use of blacklists and whitelists. While the
restriction of network access through the use of lists is straightforward, an individual person is not
identified by a MAC address, rather a device only, so an authorized person will need to have a whitelist
entry for each device that he or she would use to access the network.
Incorrect Answers:
B: The new virtual server’s MAC address triggering a port security violation on the switch may happen if
the MAC address was not added to the ACL on the switch. However, the port security violation is not the
actual cause of the users being unable to connect to the server. The MAC address not being added to the
ACL on the switch is what would prevent the users connecting to the server. Therefore this answer is
incorrect.
C: The new virtual server’s MAC address triggering an implicit deny in the switch would happen if the
MAC address met a condition that caused the deny. This is unlikely. The MAC address not being added to
the ACL on the switch to allow access if more likely. Therefore this answer is incorrect.
D: Dedicated network switches don’t tend to have firewalls. A typical home wireless router may function
as a switch and a firewall. However, even in this case, the firewall typically wouldn’t prevent
communications between devices connected to the switch. This answer is very unlikely and is therefore
incorrect.
http://en.wikipedia.org/wiki/MAC_filtering