Answer / jerald

Proxy ARP (RFC 1027) is a way to make a machine physically
located on one network appear to be logically part of a
different physical network connected to the same
router/firewall. Typically it allows us to hide a machine
with a public IP address on a private network behind a
router, and still have the machine appear to be on the
public network "in front of" the router. The
router "proxys" ARP requests and all network traffic to and
from the hidden machine to make this fiction possible.

Consider a router with two interface cards, one connected
to a public network PUBNET and one connected to a private
network PRIVNET. We want to hide a server machine on the
PRIVNET network but have it accessible from the PUBNET
network. The IP address of the server machine lies in the
PUBNET network, even though we are placing the machine on
the PRIVNET network behind the router.

By enabling proxy ARP on the router, any machine on the
PUBNET network that issues an ARP "who has" request for the
server's MAC address will get a proxy ARP reply from the
router containing the router's MAC address. This tells
machines on the PUBNET network that they should be sending
packets destined for the server via the router. The router
forwards the packets from the machines on the PUBNET
network to the server on the PRIVNET network.

Similarly, when the server on the PRIVNET network issues
a "who has" request for any machines on the PUBNET network,
the router provides its own MAC address via proxy ARP. This
tells the server to send packets for machines on the PUBNET
network via the router. The router forwards the packets
from the server on the PRIVNET network to the machines on
the PUBNET network.

The proxy ARP provided by the router allows the server on
the PRIVNETnetwork to appear to be on the PUBNET network.
It lets the router pass ARP requests and other network
packets in both directions between the server machine and
the PUBNET network, making the server machine appear to be
connected to the PUBNET network even though it is on the
PRIVNET network hidden behind the router.

What is the default LMI type for Cisco Routers that are using Frame-Relay? A.) Gandalf5 B.) Q933A C.) Cisco D.) IETF E.) ARPA F.) SAP

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Frame relay technology works on which layer of osi model?

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The following is partial output from a routing table ; '192.168.10.0 [100/1300] via 10.1.0.1, 00:00:23, Ethernet1' Which routing protocol is being used? (assuming defaults have not been changed) A.) OSPF B.) RIP C.) BGP D.) IGRP

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Novell NetWare has an Ethernet frame type called Ethernet_SNAP. What is the matching Cisco command line keyword for this encapsulation method? A.) arpa B.) sap C.) snap D.) gns E.) dix F.) novell-ether

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Identify the purpose of the wildcard mask? A.) Match a certain portion of the IP address while ignoring the rest of the address B.) Determine the class of the IP address C.) Determine the network portion of an IP address D.) Hide the host portion of an IP address

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You are a network administrator and have been assigned the IP address of 201.222.5.0. You need to have 20 subnets with 5 hosts per subnet. What subnet mask will you use? A. 255.255.255.248 B. 255.255.255.128 C. 255.255.255.192 D. 255.255.255.240

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What is an autonomous system?

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You want to enable both arpa and snap encapsulation on one router interface. How do you do this? A. The interface can handle multiple encapsulation types with no extra configuration. B. Assign two network numbers, one for each encapsulation type. C. Enable Novell-ether to run multiple encapsulation types. D. Both arpa and snap are enabled by default so you don't have to configure anything.

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2500 Value in which type of access list?

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Explain the difference between half-duplex and full-duplex?

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How many types of ospf configuration?

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