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`R1->R5->R4` and `R3->R2->R4`
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The network below uses port forwarding tables. It has been running for several hours and all hosts have exchanged packets. What is the content of the port forwarding tables ?
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At this point, a new link is added between `R1` and `R3`. What happens for the forwarding of packets ?
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The network below uses port forwarding tables. What happens if host `A` moves by removing its link with `R1` and replacing it with a link with `R3`? How should networks using port forwarding deal with such mobile hosts ?
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Some hosts need to be multihomed, i.e. attached to two different network nodes as shown in the figure below.
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Would this network work correctly with port-forwarding tables if :
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Host `A` uses the same flat address for both links.
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Host `A` uses a different flat address on each of its links
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What are the advantages and drawbacks of flat addresses versus hierarchical addresses ?
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Let us now consider the transient problems that mainly happen when the network topology changes. For this, consider the network topology shown in the figure below and assume that all routers use a distance vector protocol that uses split horizon.
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If you compute the routing tables of all routers in this network, you would obtain a table such as the table below :
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Destination
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Routes on A
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Routes on B
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Routes on C
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Routes on D
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Routes on E
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A
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0
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1 via A
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