Solution for ping incompatibility between GNS3 router devices

0x00 experimental environment

	Name	Edition
Host OS	Window 7
simulator	GNS3	v2.2.8
	GNS3 vm	v2.2.8
virtual machine	VMware	15
Router Mirror	c7200	adventerprisek9

0x01 Network Topology

0x02 problem description

Host PC1 ping does not pass through f1 port of router R1

Similarly, router R1 ping s the e0 port of host PC1

Ideas for sorting out 0x03

1. Is the GNS3 software itself functioning properly

Whether the VM can be connected properly or not, because my environment is running on gns3 vm, so I need to pay attention to it. Normally, there will be no problem if the VM is not on my computer.

Check that the analog devices used in the experiment are all on.

2. Check the configuration of the router

View an introduction to interface

Check if the FastEthernet1/0 network card is on, up is OK

Router>show ip interface brief
Interface                  IP-Address      OK? Method Status                Protocol
FastEthernet0/0            10.10.10.10     YES NVRAM  down                  down
GigabitEthernet0/1         unassigned      YES NVRAM  administratively down down
GigabitEthernet0/2         unassigned      YES NVRAM  administratively down down
GigabitEthernet0/3         unassigned      YES NVRAM  administratively down down
FastEthernet1/0            10.67.8.52      YES manual up                    up
FastEthernet2/0            unassigned      YES unset  administratively down down
FastEthernet3/0            unassigned      YES unset  administratively down down
FastEthernet4/0            unassigned      YES unset  administratively down down
SSLVPN-VIF0                unassigned      NO  unset  up                    up

View Routes
Use enable to enter privileged mode
Execute the command show ip route to view the router's routing settings

Router>enable
Router#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is 10.67.255.254 to network 0.0.0.0

     10.0.0.0/16 is subnetted, 1 subnets
C       10.67.0.0 is directly connected, FastEthernet1/0
S*   0.0.0.0/0 [1/0] via 10.67.255.254

As described in the accompanying description, C indicates the connected state, and the FastEthernet1/0 interface state is normal.Here's one thing: I used GigabitEthernet1/0 before, and I couldn't live or die. Instead of deleting PA-GE on R1, I could ping it.

Of course, if you don't have a route, it must be problematic

Pass down the command to configure the routing FastEthernet1/0 interface

Router>enable
Router#configure t
Router(config)#interface fastEthernet 1/0
Router(config-if)#ip add 10.67.8.52 255.255.0.0
Router(config-if)#no shutdown
Router(config-if)#ip route 0.0.0.0 0.0.0.0 10.67.255.254
Router(config)#end
Router#write

View Host Configuration
Use the command show ip to view the IP configuration of PC1, neither ipconfig nor ifconfig

To get command syntax help, please enter '?' as an argument of the command.

PC1> show ip

NAME        : PC1[1]
IP/MASK     : 0.0.0.0/0
GATEWAY     : 0.0.0.0
DNS         :
MAC         : 00:50:79:66:68:03
LPORT       : 20008
RHOST:PORT  : 127.0.0.1:20009
MTU:        : 1500

Found that only 127.0.0.1 did not meet the expected 10.67.8.100, reconfigure immediately

10.67.8.100 is local ip, 10.67.8.52 is gateway
The commands are as follows:

PC1> ip 10.67.8.100/16 10.67.8.52
Checking for duplicate address...
PC1 : 10.67.8.100 255.255.0.0 gateway 10.67.8.52

Re-view ip configuration, set up

PC1> show ip

NAME        : PC1[1]
IP/MASK     : 10.67.8.100/16
GATEWAY     : 10.67.8.52
DNS         :
MAC         : 00:50:79:66:68:03
LPORT       : 20008
RHOST:PORT  : 127.0.0.1:20009
MTU:        : 1500

3. Check if the devices can ping each other

Router ping host

If you start with unsuccessful situations, you will be prompted that the success rate is 0

Router#ping 10.67.8.101

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.67.8.101, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

The success rate is 4/5.Very stable 4/5

Router#ping 10.67.8.100

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.67.8.100, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 8/23/40 ms

Of course, ping native address 127.0.0.1 is not available, probably not

Host ping router/gateway

Under normal conditions, it can ping

PC1> ping 10.67.8.52
84 bytes from 10.67.8.52 icmp_seq=1 ttl=255 time=9.829 ms
84 bytes from 10.67.8.52 icmp_seq=2 ttl=255 time=3.069 ms
84 bytes from 10.67.8.52 icmp_seq=3 ttl=255 time=10.362 ms
84 bytes from 10.67.8.52 icmp_seq=4 ttl=255 time=3.563 ms
84 bytes from 10.67.8.52 icmp_seq=5 ttl=255 time=6.078 ms

Testing local is not feasible.

PC1> ping localhost
Cannot resolve localhost

PC1> ping 127.0.0.1
127.0.0.1 icmp_seq=1 timeout
127.0.0.1 icmp_seq=2 timeout
127.0.0.1 icmp_seq=3 timeout
127.0.0.1 icmp_seq=4 timeout
127.0.0.1 icmp_seq=5 timeout

PC1> show ip

NAME        : PC1[1]
IP/MASK     : 10.67.8.100/16
GATEWAY     : 10.67.8.52
DNS         :
MAC         : 00:50:79:66:68:03
LPORT       : 20008
RHOST:PORT  : 127.0.0.1:20009
MTU:        : 1500

Reference

https://blog.51cto.com/gezhongyun/1297611
https://www.cnblogs.com/sherlock-tang/p/7887119.html

Posted by eternalprophet on Thu, 11 Jun 2020 18:49:34 -0700

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