On GNS3 I have developed the following network:
The enp2s0f2 is my own computer network interface.
The router R1 configuration is shown below:
R1#show running-config Building configuration... Current configuration : 1077 bytes ! version 12.4 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname R1 ! boot-start-marker boot-end-marker ! ! no aaa new-model memory-size iomem 5 no ip icmp rate-limit unreachable ip cef ! ! no ip dhcp use vrf connected ! ip dhcp pool INTERNAL-CLIENT network 172.17.0.0 255.255.255.0 default-router 172.17.0.1 dns-server 1.1.1.1 ! ! ip name-server 1.1.1.1 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ip tcp synwait-time 5 ! ! ! interface FastEthernet0/0 ip address dhcp ip nat outside duplex auto speed auto ! interface FastEthernet0/1 ip address 172.17.0.1 255.255.255.0 ip nat inside duplex auto speed auto ! ! ! no ip http server no ip http secure-server ip nat inside source list 1 interface FastEthernet0/0 overload ! access-list 1 permit 172.17.0.0 0.0.0.255 no cdp log mismatch duplex ! ! ! control-plane ! ! ! ! ! ! ! ! ! line con 0 exec-timeout 0 0 privilege level 15 logging synchronous line aux 0 exec-timeout 0 0 privilege level 15 logging synchronous line vty 0 4 login ! ! end R1#
On PC-1 I have:
PC-1> show ip all NAME IP/MASK GATEWAY MAC DNS PC-1 172.17.0.2/24 172.17.0.1 00:50:79:66:68:00 1.1.1.1
On router R1, I have:
R1#show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 192.168.10.166 YES DHCP up up FastEthernet0/1 172.17.0.1 YES NVRAM up up NVI0 unassigned NO unset up up R1#
On my physical computer I have:
$ ip address
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp2s0f2: mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 70:4d:7b:3a:6e:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.10.231/16 brd 192.168.255.255 scope global dynamic enp2s0f2
valid_lft 343522sec preferred_lft 343522sec
inet6 fe80::f39e:90d0:970:b350/64 scope link
valid_lft forever preferred_lft forever
3: wlp3s0: mtu 1500 qdisc mq state DOWN group default qlen 1000
link/ether 94:e9:79:2a:34:23 brd ff:ff:ff:ff:ff:ff
The point which I don't understand is that, on PC1, I can ping the google.com, 192.168.10.254 (gateway of my physical network) and 192.168.10.166 (IP of R1 interface), however I can NOT ping the 192.168.10.231 which is the IP of my physical computer which has the interface enp2s0f2, like below:
PC-1> ping google.com google.com resolved to 172.217.21.238 84 bytes from 172.217.21.238 icmp_seq=1 ttl=46 time=211.381 ms 84 bytes from 172.217.21.238 icmp_seq=2 ttl=46 time=151.149 ms 84 bytes from 172.217.21.238 icmp_seq=3 ttl=46 time=139.226 ms 84 bytes from 172.217.21.238 icmp_seq=4 ttl=46 time=171.411 ms 84 bytes from 172.217.21.238 icmp_seq=5 ttl=46 time=201.004 ms PC-1> ping 192.168.10.254 84 bytes from 192.168.10.254 icmp_seq=1 ttl=63 time=14.656 ms 84 bytes from 192.168.10.254 icmp_seq=2 ttl=63 time=29.997 ms 84 bytes from 192.168.10.254 icmp_seq=3 ttl=63 time=23.611 ms 84 bytes from 192.168.10.254 icmp_seq=4 ttl=63 time=29.338 ms 84 bytes from 192.168.10.254 icmp_seq=5 ttl=63 time=29.783 ms PC-1> ping 192.168.10.166 84 bytes from 192.168.10.166 icmp_seq=1 ttl=255 time=2.785 ms 84 bytes from 192.168.10.166 icmp_seq=2 ttl=255 time=9.686 ms 84 bytes from 192.168.10.166 icmp_seq=3 ttl=255 time=10.499 ms 84 bytes from 192.168.10.166 icmp_seq=4 ttl=255 time=9.364 ms 84 bytes from 192.168.10.166 icmp_seq=5 ttl=255 time=11.252 ms PC-1> ping 192.168.10.231 192.168.10.231 icmp_seq=1 timeout 192.168.10.231 icmp_seq=2 timeout 192.168.10.231 icmp_seq=3 timeout 192.168.10.231 icmp_seq=4 timeout 192.168.10.231 icmp_seq=5 timeout PC-1>
I couldn't understand why I cannot ping my physical computer from within the virtual PC-1 inside GNS3. Also, I cannot ping the router R1 interface from within the physical computer:
$ ping 192.168.10.166 PING 192.168.10.166 (192.168.10.166) 56(84) bytes of data. From 192.168.10.231 icmp_seq=1 Destination Host Unreachable From 192.168.10.231 icmp_seq=2 Destination Host Unreachable From 192.168.10.231 icmp_seq=3 Destination Host Unreachable From 192.168.10.231 icmp_seq=4 Destination Host Unreachable From 192.168.10.231 icmp_seq=5 Destination Host Unreachable From 192.168.10.231 icmp_seq=6 Destination Host Unreachable
Here is my routing table on the physical computer:
$ route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.10.254 0.0.0.0 UG 20100 0 0 enp2s0f2 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 enp2s0f2 192.168.0.0 0.0.0.0 255.255.0.0 U 100 0 0 enp2s0f2
