- Router:
- Router =
a networking device that can
inter-connect
multiple
heterogeneous
(and also
homogeneous)
networks
- Router =
a networking device that can
inter-connect
multiple
heterogeneous
(and also
homogeneous)
networks
- Furthermore:
- A router
knows (= programmed):
- The structure of a layer 3 frame (= IP packet)
- A router
knows (= programmed):
- Receiving data:
- Receive data = having the ability to extract the data from a frame and interpret some portion of the data
Illustrated:
- A sends some
data in
an Ethernet frame:
- Router can
receive the
data if
the router can
extract the
data and
interpret
some portion of the
data:
- Capabilities of
a router:
- A Router can
receive
layer 2 frames
from any (attached) network:
Note:
- Data will be an IP packet (see later)
- The router can
interpret (= understand)
the header information inside
the data (= IP packet)
- The header portion of
the data (= IP packet) contains the
destination IP address
- The router will use the destination address to decide where (= which output) to send the data (= IP packet) next
- The header portion of
the data (= IP packet) contains the
destination IP address
- A Router can
transmit the data
(= IP packet)
in a
layer 2 frame
on any (attached) network:
- A Router can
receive
layer 2 frames
from any (attached) network:
- A router knows the
structure of
an IP packet:
- A router can read:
- the source IP address in an IP packet
- the destination IP address in an IP packet
Graphically:
- A router can read:
- The router will
transmit the
IP packet
(unchanged)
as data
in a
level 2
(Ethernet/Token ring) frame:
