experiment one:
Static Routing experimental environment to build a case:
the need to use our previously installed software GNS3 and two CRT
we enter into GNS3 click on the left of the server icon, drag the election two servers to the topology console 
and then click on the icon on the left side of the PC, the same drag two PC connected to the topology console to prepare 
the ready we click on the icon to the left of the cable connected to them, and at the same time click display port numbers 
Let us first look at pre-set IP addresses per port, this Note that at the ports at both ends of the network router is different from 
the green triangle icon click to open the top of the entry line, and then were double-click the R1 / R2 / PC1 / PC2 ,, Jump into the CRT interface 
Next we need to do is first, with two ports on the IP address of the router R1:
1. enter into the overall pattern conf t
2. enter int f0 / 0 0/0 entering this interface
3. the input write ip address 192.168.10.1 255.255.255.0 IP address, knock enter
4. enter the unblock interface no shut down
operations below: 
next, in R1 f0 / 1 interfaces with an IP address, a port in the current mode:
1. enter int f0 / 1 0/1 entering this interface
2. enter ip address 192.168.20.1 255.255.255.0 write IP address, hit Enter
3. Enter the no shut down open interfaces
4. Enter do show ip int b cross-check the IP address mode
operation as shown below: 
Next we need to accompanied by static:
1. ex input into the global schema
2. Enter the ip route 192.168.30.0 255.255.255.0 192.168.20.2 (192.168.20.2 here, the IP address of the next hop)
3. Enter do show ip route routing table display, this time generating static
operation as shown below: 
Next, the R2 IP settings and the same R1, the specific steps below:
at this point we are not on the route back with R2, if this time we enter PC1 verify operation as follows:
input: ip 192.168.10.10 192.168.10.1 hit the enter
at this time, the gateway automatically generates
specific operation as shown below: 
we perform the same operation into the PC2, the same result obtained,
the specific operation as shown below: 
after the automatic generation of the gateway, then we can try Unicom ping command
input: ping 192.168.30.30 knock Enter, the results obtained for the time out: 
why do not communicate here?
R2 routing table because incomplete, lost after data reaches R 2, as R2 does not know how reach 10 passages, if resolved, if desired, coupled with the IP address of this paragraph in the R2 10, the operation as shown below: 
This time we return interface type to PC1 ping 192.168.30.30, the communication status at this time, as shown below:
Experiment two:
We put all the empty set inside R2 (R2, right click, select STOP to stop, and then select start to start, it is reset), this time with the ping command to test interoperability is unable to communicate 
at this time we try to set the default route on R2 we enter the command into the R2, FIG follows: 
1. input ex back to the global mode
2. enter the ip route 0.0.0.0 0.0.0.0 192.168.20.1 hit enter
steps and obtained the results as shown below: 
we go back to PC1 interoperability test, enter: ping 192.168.30.30 hit enter, at this time there will be communicated after two packet loss, packet loss is because the two temporarily lost during the arp broadcast, and follow-up is still Unicom