![Verify Connectivity of Directly Connected Networks (1.1.4) > Cisco Networking Academy's Introduction to Routing Concepts | Cisco Press Verify Connectivity of Directly Connected Networks (1.1.4) > Cisco Networking Academy's Introduction to Routing Concepts | Cisco Press](https://www.ciscopress.com/content/images/chap1_9781587133237/elementLinks/01fig17.jpg)
Verify Connectivity of Directly Connected Networks (1.1.4) > Cisco Networking Academy's Introduction to Routing Concepts | Cisco Press
Refer to the exhibit. The command _show interface serial 1/0 is issued on the Router _R4, for some reason the physical line is up, but there is no connectivity between both routers.
![How to Configure Cisco Router Interfaces (FastEthernet and Serial Interfaces)-Cisco Certifications – UPaae How to Configure Cisco Router Interfaces (FastEthernet and Serial Interfaces)-Cisco Certifications – UPaae](http://upaae.com/wp-content/uploads/2016/08/config-interface-1.jpg)