Cisco will typically make any newer topics somewhat easier to start with. You can count on more difficult questions from wireless, cyber security, and SDN eventually. The top ten list includes newer topics and core networking topics.
This is a skill required across a variety of CCNA topics and questions. Subnetting is required to configure network interfaces and read a routing table. You should know how to distinguish between classful and classless addressing, and when to apply subnet masks or wildcard masks.
In fact, subnet masks and wildcard masks affect what routes are advertised from a routing protocol to neighbor routers . Learn binary to decimal conversion and how to create your own subnetting table for quick reference. Consider as well that DHCP, DNS and NAT are all network addressing services.
Do you know how to read a routing table, and how a route (prefix) is selected when multiple routes exist to a destination? You should know how to list routing tables for IPv4 and IPv6 protocols. Subnetting knowledge is also required when a host IP address exists within multiple prefixes.
So the questions will test your knowledge of administrative distance, longest match rule, path metrics, and subnetting. Study protocol operation for OSPF and rules for establishing network connectivity. You are often tested on your knowledge of multiple topics with a single question.
Routing Protocol: OSPF Version 2
There is a significant shift now to an internet-based IP connectivity model. OSPFv2 is a scalable IPv4-only routing protocol. EIGRP was previously created for multiprotocol routing and RIP is not scalable for mobile and cloud connections.
There are several layers of knowledge with OSPFv2 routing protocol and significant coverage. It is the only routing protocol included with the new exam. Know how to do basic configuration of single-area and verify your configuration for neighbor connectivity. Know administrative distance, metrics and OSPF neighbor adjacency. Understand how designated routers (DR) are elected and router ID for single-area OSPFv2.
There is now coverage of wireless fundamentals and configuration topics on the upcoming CCNA exam. You will have to know RF cell characteristics along with SSID, channel allocation and WPA2 security protocol. There are going to be questions as well on wireless architectures and managing devices. In fact wireless is going to cross multiple domains.
Not a surprise that security has been expanded and now on the top ten list of must know for the CCNA exam. In fact, CCNA security certification is becoming quite popular with the complexity of public internet connections and creativity of hacker attacks. The CCNA topics are basic and very reasonable testing your knowledge of initial setup and recommended commands for device hardening of routers and switches.
The primary topics include console security, enable passwords, VTY line access, password encryption and SSH. In addition there is ARP inspection, DHCP snooping and newer wireless encryption protocols. Cisco has added what could be termed security management topics as well. That is the result of so much internet cloud connectivity.
Most routers will have at least one routing protocol enabled to advertise local subnets and receive routes from neighbors. Most routers are going to have some static routes for a variety of purposes. There is some additional maintenance and complexity that goes along with any dynamic routing protocols.
Static routes also include default routes and floating routes common to most configurations. Most internet connections from a branch office will require only a default route. You have to know static routing to read a routing table and understand how they affect route selection.
Switch trunking requires that you first understand switch interfaces, VLANs, encapsulation and VLAN pruning. As a result the questions are really testing your knowledge of multiple switching concepts.
Practically speaking all switches have trunk interfaces and they enable communication between multiple VLAN segments. DTP is a dynamic trunking alternative to static trunk interfaces with multiple modes that control when a trunk is established between switches.
Access Control Lists (ACL)
When it comes to the CCNA exam, learn as much as you can about all types of ACLs. There are four groups: standard ACL, standard named ACL, extended ACL and extended named ACL. They are so prevalent on routers and firewalls that you have to know basic configuration of an ACL and also how to apply them correctly.
ACLs affect how traffic filtering works and is key to network security. Any ACL requires a filter command along with a direction and network interface as primary attributes to permit or deny traffic.
Automation and Programmability
CCNA 200-301 exam includes a significant amount of wireless and network programmability. That is attributed to the popularity of mobile devices, cloud computing and SDN architecture. Cisco is aligning the CCNA certification exam with a shift to internet-based connectivity model.
The management and troubleshooting of network infrastructure is being radically changed with SDN open source architecture. Cisco has enabled programmable features on their devices and virtualization from physical equipment to software services. They have virtual appliances and CCNA engineers now support private and cloud data center connections.
Key topics include Cisco DNA Center along with fabric overlays, underlays and controller-based network management. Some additional topics are SDN architecture, JSON, RESTful API, and virtualization concepts.
CCNA IOS Commands
The following are core IOS commands that you must know to verify network connectivity and operational state.
- show running-config
- show ip interface brief
- show ip route
- show interfaces trunk
- show vlan
- show cdp neighbor
- show etherchannel summary
- show ip ospf neighbor
- show ip ospf interface
- show access-lists
- show ip dhcp binding
- ipconfig /all
IPv6 addressing change IOS commands slightly. For example show ip route will display all IPv4 routes in the routing table. IPv6 routes are displayed with show ipv6 route when IPv6 addressing is enabled.