How does a mobile node secure registration messages using the FA Challenge mechanism?
– To verify the integrity of a message that has an authentication extension appended, what does the
recipient do?
What are the main differences between IPv6 and IPv4?
– Consider a Mobile Node with a single interface whose Home Address is 192.168.10.30 and Home
Agent is 192.168.10.1. Let us assume that the MN roams away from home to FA 192.168.100.6, and then
to another FA, 192.168.200.6. It then finds itself still roaming, but not within the domain of a FA. At this
point, it obtains a Collocated CoA and continues to roam. After some times, it returns home. Explain step
by step of the sequences of the above problem.
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A foreign Agent may broadcast constantly advertisements by agents who have different
challenges included. Therefore a mobile node may be using unused challenges for the
authentication. For authentication to a foreign agent FA the mobile nodes have to include a new
defined extension known as MN-FA challenge extension to tell which challenge is used in its
authentication extension. Then some rules are defined to judge if an authentication extension is
valid in regard to FA change. The FA challenge is in the registration of request message with
AAA authentication extension and mobile foreign authentication extension. When an
authenticator is generated it includes the extension then the challenge is authenticated through
the foreign authentication extension.
To verify the integrity of a message that has an authentication extension appended, the
recipient will compare the value of the authenticator in the extension that is appended to that in
storage.
IPv4 is the old version of protocol used for internet. It numeric address is written in 32-
bit decimal of four numbers kept apart by a period .This numbers are within the range of zero to
255.For example 0. 0 .0 .0 to 255 .255. 255. 255.While IPv6 is newer version of internet protocol
with a 128-bit numeric addresses which are written in hexadecimal.
The micro mobility is a term that means the mobile node’s movements are inside a
network. While in contrast, the macro mobility means that there is movement between different
sub networks.
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WiMAX produces products that are used by wireless metropolitan networks (WMANs).
while products made of Wi-Fi are built to be used in wireless Local Area network ( WLANs).
As MN leaves the address number 1it has to notify MN other network of the roaming
and tells it to take care of its address.
It is false that before 802.11 stations transmits a data frame it first must send an Rts frame
and a corresponding CTS frame.
The switch contains an entry in the switch forwarding table it connects the wireless
station with the earlier AP. Then the new AP creates wireless frame station’s MAC and
broadcasts the frames this frame will be received by another switch then the switch updates the
forwarding table then the frame is forwarded to the wireless station through the new AP.
The Aps will have varying SSIDs and MAC addresses. A wireless station arriving to the café
will associate with one of the SSIDs in one of the APs. After the connection their important link
connecting the station. Taking the two Aps to be 1AP and 2AP the new station connects with
1AP then sends a frame when 2AP receives the frame it will not be able to processes the reason
being that it is not addressed to it therefore the internet service providers can transmit at the
same time in parallel otherwise their the two ISPs have the ability to work in parallel on the
same channel. Moreover the two ISPs will be using the same wireless bandwidth. If wireless
stations in different ISPs transmit at the same time, there will be a collision. For 802.11b, the
maximum total transmission rate when it comes to both ISPs 11MBPs.
Dynamics is a program that is developed in TKK then it is implemented in the
hierarchical IP. From that we can deduce that their can exist a hierarchy of FA in the midst of
HA and MN. This hierarchy is in a treelike structure. The FA in the lowest level communicates
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with the MN. The main aim of the hierarchy is to allow Mobile IP scale well quickly to give
better HO. MN doesn’t always have to register to a HA, but while moving within the FA
hierarchy the tunneling can be changed internally without concerning the HA which can be
located on the other side of the world and the connections can be much faster in across the FA.
The exchange protocol is internetwork Packet Exchange (IPX) operates at as a network
layer protocol it is found inside the IPX/SPX protocol suite . IPX is an easy configuration of the
client computers
Mobile IP entities
Mobile Node (MN)–this is a program that moves the point of attachment to different networks.
Home Agent (HA)–keeps the current location information for the mobile node. This is a router
on a mobile node’s home network that dissects data destined through the mobile node; they are
later delivered through the care-of address.
Foreign Agent (FA)–Router on a mobile node’s sojourned network, it gives routing services to
the mobile node while the mobile node is registered.
Steps in handing over from one agent to another is
1) Scanning the medium decide
2) the base station
3) decide on one of them
4) reroute data inside the infrastructure network
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5) release resources with the old base station. .
In TCP packets are prone to loss while it is implemented on a wireless network due to
congestion and in mobile networks when TCP packets are lost due to disconnection, handoffs
and high bit error rates.
Snoop has a duty of reducing the retransmission rate regardless of transmission error.rors,
and a delivery that is out-of-order on the wireless link. The problem snoop is when the MH is the
sending TCP is that it will not retransmit for safe delivery. One of the solutions is to ensure that
MH is the receiving TCP.
ACK has the ability to be to bring up greater delay as it associates with other application
and arrangement. If algorithm in use is Nagle’s algorithm you send a third party, the data will be
arranged by the sender up to when an ACK is received. In case the sender will not send enough
packets to fill a segment size the transfer will be at a stand still until when the ACK delay
timeout.
It can happen that Two mobile have the same care-of –address in the same Foreign
agent. This is because when it happens that the care-of-address is the address of the visited
network, then the addresses will happen to be equal. Once the visited network opens the received
datagram and decides the address of the mobile and then separates addresses that will have to be
in use when sending the packets differently and separately across mobiles in a Foreign Agent.
When a Mobile user is received by a Foreign Network and links to the network, the Mobile
Node gets an IP addresses. Then the Mobile Node is started to run a Registration Protocol.
Registration Protocol is used hierarchically and the tunnel is brought forth through the Foreign
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Agent hierarchy following specific procedure. Each Foreign Agent on the way can check for a
tunnel for the specified Mobile node , This will enable them to produce local tunnel updates to
give new registration, the protocol goes up to the Home Node which then confirms the tunnel
creation. Tunnels are created in a descending order after the MN has been accepted properly by
the HA. The lifetime of the tunnel is decided upon during registration by the Mobility Agents .To
keep the tunnel open keep Alive protocol is used. The messages includes A foreign Agent may
broadcast constantly advertisements by agents who have different challenges included. Therefore
a mobile node may be using unused challenges for the authentication. For authentication to a
foreign agent FA the MN have to include a new defined extension known as MN-FA challenge
extension to tell which challenge is used in its authentication extension. Then some rules are
defined to judge if an authentication extension is valid in regard to FA change. The FA challenge
is in the registration of request message with AAA authentication extension and mobile foreign
authentication extension. When an authenticator is generated it includes the extension then the
challenge is authenticated through the foreign authentication extension. Then CN send a
confirmation message.
Even when the CN moves to another network they will still communicate since it will be
registered on the foreign network with the same Care Address but the messages will be routed to
the new network following the same sequence.
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References
Oracle, (2015).Retrieved
