Johan does not have a default gateway entered on his Windows
98 system. He cannot send or receive e-mail to and from the Internet, but he can
exchange e-mail over his local subnet and the rest of the internal network. He can
also browse the World Wide Web. How is this possible?
A.
Johan is using a packet filter on his system.
B.
Johan is using a Proxy server on his system.
C.
Johan is accessing a Proxy server.
D.
Johan is using a protocol other than TCP/IP to access the web.
Explanation:
Without the default gateway, Johan cannot access other subnets.
However, if the proxy server is on the same subnet, then it can receive the calls and
provide access to the Internet for WWW access. Unless a winsock proxy is being
used, Johan cannot access e-mail servers on the Internet. It is also possible that the
ports for e-mail are disabled on the proxy server. He can exchange e-mail on his
local subnet and the rest of the network because the e-mail server is on is subnet.
Getting e-mail to the mail server on his same subnet does not prevent the mail from
reaching the rest of the network, since it is the mail server that actually does the
delivery to the users outside the subnet.
Incorrect Answers:
A: A packet filter on his system may prevent access to certain protocols and addresses,but it can’t
extend his reach through a router and onto the Internet. Packet Filters onlyrestrict.
B: Having a proxy server on his system would still require a default gateway, and wouldnot
properly work without one.
D: TCP/IP is the only protocol that is used with the WWW, so he can’t be using adifferent protocol.