Exam 350-401 topic 1 question 478 discussion

Provided answer is correct. I tested this in GNS3. Kept the subnet mask on one side /30 and the other side /29. Got on one side debug outputs: *Sep 8 22:58:38.295: IP ARP req filtered src 10.10.12.1 ca01.37c4.0000, dst 10.10.12.5 0000.0000.0000 wrong cable, interface FastEthernet0/0 And the other side: *Sep 8 22:58:37.747: IP ARP: creating incomplete entry for IP address: 10.10.12.5 interface FastEthernet0/0 The output with wrong cable is misleading.

A is correct /30 and /24

As the routers are directly connected, then they should have the same subnet but they don't have. One is /30 and the other is /29.

! interface Ethernet0/0.70 encapsulation dot1Q 70 ip address 10.111.12.6 255.255.255.248 end cisco_R5#ping 10.111.12.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.111.12.1, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) cisco_R5#show ip arp Protocol Address Age (min) Hardware Addr Type Interface Internet 10.111.10.1 194 aabb.cc00.3000 ARPA Ethernet0/0.50 Internet 10.111.10.2 - aabb.cc00.5000 ARPA Ethernet0/0.50 Internet 10.111.12.1 0 Incomplete ARPA <<<<<<<<<<<<<<<<<<<<<<<<<< Internet 10.111.12.6 - aabb.cc00.5000 ARPA Ethernet0/0.70 Internet 192.168.255.2 126 aabb.cc80.1000 ARPA Ethernet0/0.10 Internet 192.168.255.3 192 aabb.cc00.3000 ARPA Ethernet0/0.10 Internet 192.168.255.22 195 aabb.cc00.2000 ARPA Ethernet0/0.10 Internet 192.168.255.55 - aabb.cc00.5000 ARPA Ethernet0/0.10 cisco_R5#

shouldn't be C?