- Things that we
still need to
discuss:
- Constructing
the Routing Table
- In the examples,
the content of
the routing table
(and the forwarding table)
have been setup already)
- We will discuss how the routing tables are setup - this will be discussed in a later lecture (routing): click here
- In the examples,
the content of
the routing table
(and the forwarding table)
have been setup already)
- Discovering
the physical (e.g., Ethernet) address
of a host
- IP packets
are transmitted inside
a
physical network frame
(e.g., an Ethernet frame):
In order to transmit the IP packet to a node:
- A source must know the physical (Ethernet) address for a given IP address !!!
Graphically:
Problem:
- How can the router B find the Ethernet address of a host that has the IP address IP5 ????
This problem will be solved by the Address Resolution Protocol (ARP) - discussed later.
- IP packets
are transmitted inside
a
physical network frame
(e.g., an Ethernet frame):
- Assign
an IP address and
configure the
IP forwarding/routing table of
a node
automatically
(when a node starts up)
- Manual configuration:
- Give a computer a
unique IP address
(must have the
correct network prefix)
- Set up the IP forwarding table
- Set up the IP routing table
But that is very time consuming when you have to setup hundred of computers
- Give a computer a
unique IP address
(must have the
correct network prefix)
We will discuss an automated way to assign IP addresses and configure the IP forwarding/routing table
- The solution is the Dynamic Host Configuration Protocol (DHCP)...
- Manual configuration:
- Constructing
the Routing Table