CompTIA^® Network+ Lab Exercise : Designing A Home Network With A Router, Access Point, And Wireless Work Stations

DHCP Range on Server:

Start IP: 192.168.1.65

Stop IP: 192.168.1.128

Subnet mask: 255.255.255.192

Default Gateway: 192.168.1.1

Router R1 configuration:

E0: 192.168.1.1

255.255.255.192

S0: 202.100.15.10

Subnet mask: 255.255.255.64

On R1

R1>enable
R1#configure terminal
R1(config)#interface ethernet 0
R1(config-if)#ip address 192.168.1.1 255.255.255.192
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface serial 0
R1(config-if)#ip address 202.100.15.10 255.255.255.64
R1(config-if)#no shutdown
R1(config-if)#exit

Client Configurations:

All wired workstations have been configured to obtain the IP settings from DHCP server. It was reported that none of the wired workstations WS1 and WS2 are able to ping the Router R1's E0 interface (Default Gateway). The technician had checked all the physical connections are found them to be in order.What is the most likely problem?

Solution:

In the above scenario, the DHCP scope was set wrongly on the DHCP Server. The DHCP scope of 192.168.1.65 to 192.168.1.128 corresponds to subnet ID 192.168.1.64 where as the default gateway (192.168.1.1) corresponds to subnet ID 192.168.1.0. By correcting the DHCP scope to 192.168.1.3 to 192.168.1.63 (note that 192.168.1.1 and 192.168.1.2 have been used for static assignment) the problem could be solved.

Instructions:

1. Open the Server configuration window.

2. Change the Start IP to 192.168.1.3 and Stop IP to 192.168.1.62 (Note that 192.168.1.63 is broadcast address and can't be used. 192.168.1.1 is the IP address of default gateway, and 192.168.1.2 is statically assigned to DHCP Server).

3. Ping to default gateway from WS1 or WS2 should success.

WS1:ping 192.168.1.1
Type escape sequence to abort.
Sending 5,100-byte ICMP Echos to  192.168.1.1 ,
Timeout is 2 seconds:
 !!!!! 
Success rate is 100 percent (5/5), round-trip min/avg/max = 6/6/6 ms

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