Information Technology Reference
In-Depth Information
Finally, you should document your network implementation. On each router, capture the following
command output to a text (.txt) file and save for future reference.
show running-config
show ip route
show ip interface brief
If you need to review the procedures for capturing command output, see “Lab 1-1: Cabling a Network
and Basic Router Configuration (1.5.1).”
Task 13: Clean Up
Erase the configurations and reload the routers. Disconnect and store the cabling. For PC hosts that
are normally connected to other networks (such as the school LAN or the Internet), reconnect the
appropriate cabling and restore the TCP/IP settings.
Task 14: Challenge
In the following exercise, fill in the blanks to document the process as the ping travels from source to
destination.
The ICMP process on PC3 formulates a ping request to PC2 and sends the reply to the IP
process.
1.
The IP process on PC3 encapsulates the ping packet with a source IP address of
192.168.2.10
and destination IP address of
172.16.1.10
.
2.
PC3 then frames the packet with the source MAC address of (indicate device name)
PC3
and
the destination MAC address of (indicate device name)
R3
.
3.
Next, PC3 sends the frame out on the media as an encoded bit stream.
4.
R3 receives the bit stream on its
Fa0/0
interface. Because the destination MAC address matches
the receiving interface's MAC address, R3 strips off the Ethernet header.
5.
R3 looks up the destination network address
172.16.1.0/24
in its routing table. This destination
has a next-hop IP address of
192.168.1.2
. The next-hop IP address is reachable out interface
S0/0/1
.
6.
R3 encapsulates the packet in an HDLC frame and forwards the frame out the correct interface.
(Because this is a point-to-point link, no address is needed. However, the address field in the
HDLC packet contains the value 0x8F.)
7.
R2 receives the frame on the
S0/0/1
interface. Because the frame is HDLC, R2 strips off the
header and looks up the network address
172.16.1.0/24
in its routing table. This destination
address is directly connected to the
Fa0/0
interface.
8.
R2 encapsulates the ping request in a frame with the source MAC address of (indicated device
name)
R2
and the destination MAC address of (indicate device name)
PC2
.
9.
R2 then sends the frame out on the media as an encoded bit stream.
10.
PC2 receives the bit stream on its
Ethernet (NIC)
interface. Because the destination MAC
address matches the MAC address of PC2, PC2 strips off the Ethernet header.
11.
The IP process on PC2 examines the
172.16.1.10
IP address to make sure that it matches its
own IP address. Then PC2 passes the data to the ICMP process.
12.
