Hi there, so {unnamed company} has set up some VLSM networks, but they overlap.
So network 1 is 10.15.0.0/16
and network 2 is 10.15.208.0/24
.
Now you can see how these overlap:
10.15.0.1 - 254.255
10.15.208.1 - 254
...they both contain 10.15.208.2
. Which is the IP of a DC on network 2.
Machines in network 1 can connect to the DC.
My question is... how?
I ran it through a simulation on a packet tracer, and I can see that hosts on network 1 send out an ARP, to which router 0 replies with its own mac address. Why is that? Is it because router 0 has a static route for 10.15.208.0/24?
What also are the implications of this strange set up?
Router0:
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.15.0.0/16 is directly connected, FastEthernet0/0
S 10.15.208.0/24 [1/0] via 192.168.0.2
C 192.168.0.0/16 is directly connected, FastEthernet0/1
Building configuration...
Current configuration : 557 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router
!
!
!
!
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
interface FastEthernet0/0
ip address 10.15.0.1 255.255.0.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 192.168.0.1 255.255.0.0
duplex auto
speed auto
!
interface Vlan1
no ip address
shutdown
!
ip classless
ip route 10.15.208.0 255.255.255.0 192.168.0.2
!
!
!
!
!
!
!
line con 0
!
line aux 0
!
line vty 0 4
login
!
!
!
end
Router1:
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
S 10.15.0.0/16 [1/0] via 192.168.0.1
C 10.15.208.0/24 is directly connected, FastEthernet0/0
C 192.168.0.0/16 is directly connected, FastEthernet0/1
Building configuration...
Current configuration : 557 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router
!
!
!
!
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
interface FastEthernet0/0
ip address 10.15.208.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 192.168.0.2 255.255.0.0
duplex auto
speed auto
!
interface Vlan1
no ip address
shutdown
!
ip classless
ip route 10.15.0.0 255.255.0.0 192.168.0.1
!
!
!
!
!
!
!
line con 0
!
line aux 0
!
line vty 0 4
login
!
!
!
end
show running-config
command, paste it into your question, and use the Preformatted Text feature ({}
). – Ron Maupin♦ Feb 9 '17 at 16:02