Cisco Certified Network Associate (CCNA) IP Connectivity Syllabus

IP Connectivity syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for IP Connectivity in Cisco Certified Network Associate (CCNA), not a summary of it.

1. 1

   Routing Fundamentals

   3 topics

   • Components of the routing table
     • Routing protocol code and prefix
     • Network mask and next hop
     • Administrative distance
     • Metric and gateway of last resort
   • Forwarding decision logic
     • Longest prefix match
     • Administrative distance comparison
     • Routing metric tie-breaking
   • Sources of routing information
     • Directly connected and local routes
     • Static routes
     • Dynamic protocol routes
2. 2

   Static Routing

   4 topics

   • IPv4 static routes
     • Network and host routes
     • Default route
     • Floating static routes
   • IPv6 static routes
     • Next-hop and exit-interface forms
   • Route specification options
     • Next-hop IP vs exit interface vs both
   • Verifying static routing
3. 3

   Dynamic Routing with OSPFv2

   5 topics

   • OSPF single-area operation
     • Process and area configuration
     • Network statements and wildcard masks
     • Passive interfaces
   • Neighbor relationships and adjacencies
     • Hello and dead timers
     • Neighbor states
     • DR/BDR election
   • OSPF metrics and identification
     • Cost calculation
     • Router ID selection
   • Point-to-point and broadcast network types
   • Verifying and troubleshooting OSPF
4. 4

   First Hop Redundancy

   3 topics

   • Purpose of first hop redundancy protocols
   • HSRP operation
     • Active/standby roles and virtual IP
     • Priority and preemption
   • Comparison of FHRP options (VRRP, GLBP)

IP Connectivity flashcards for Cisco Certified Network Associate (CCNA)

18 of 52 cards from the IP Connectivity deck — real questions with worked answers.

1. What three pieces of information does each entry in an IPv4 routing table contain?

   The destination network/prefix (network address and subnet mask/prefix length), the next-hop IP address (and/or exit interface), and metric/administrative distance information used to choose the route.

2. In the routing table, what does the code letter 'C' represent and how is its route learned?

   'C' = Connected. It is created automatically when an interface is configured with an IP address and is up/up; the router knows the network is directly attached.

3. What does the code 'L' indicate in an IPv4 routing table, and what prefix length does it use?

   'L' = Local route, the router's own interface IP address. It is installed as a /32 (host route) for IPv4 (/128 for IPv6).

4. What are the two numbers shown in brackets in a routing table entry, e.g. [110/65]?

   The first number is the administrative distance (trustworthiness of the source) and the second is the metric (cost) of that route within its routing protocol.

5. Define administrative distance (AD) and state its purpose.

   AD is a value (0-255) ranking the trustworthiness of a routing information source. When multiple sources offer a route to the same network, the router installs the one with the lowest AD.

6. List the default administrative distances for: directly connected, static, eBGP, OSPF, EIGRP (internal), and RIP.

   Connected = 0, Static = 1, eBGP = 20, EIGRP internal = 90, OSPF = 110, RIP = 120.

7. When a router has multiple matching routes to a destination, what is the order of preference for selecting which to use?

   1) Longest prefix match (most specific route) wins first; 2) if prefixes tie, lowest administrative distance; 3) if AD ties (same protocol), lowest metric.

8. What is the 'longest prefix match' rule in forwarding decisions?

   The router forwards a packet using the routing-table entry whose subnet mask/prefix is the longest (most specific) that still matches the packet's destination IP address.

9. Given routes to 10.1.1.0/24 and 10.0.0.0/8, which is used to forward a packet destined for 10.1.1.5, and why?

   The 10.1.1.0/24 route is used because /24 is a longer (more specific) prefix match than /8, regardless of administrative distance or metric.

10. What is a default route and how is it written in IPv4 and IPv6?

    A default route matches all destinations not matched by a more specific entry (the 'gateway of last resort'). IPv4: 0.0.0.0/0 (0.0.0.0 0.0.0.0). IPv6: ::/0.

11. Name the three general sources of routing information that populate a routing table.

    Directly connected networks, static routes (manually configured), and dynamic routing protocols (e.g., OSPF, EIGRP, BGP, RIP).

12. What is the command syntax to configure an IPv4 static route to network 192.168.5.0/24 via next hop 10.0.0.2?

    ip route 192.168.5.0 255.255.255.0 10.0.0.2

13. What is a floating static route and how is it created?

    A backup static route configured with an administrative distance higher than the primary route's AD (e.g., 'ip route ... 10.0.0.2 200'). It stays out of the table until the primary route fails, then 'floats' in.

14. What are the three ways a static route's destination/next-hop can be specified, and which is recommended on multi-access links?

    Next-hop IP only, exit interface only, or fully specified (exit interface + next-hop IP). Fully specified or next-hop is recommended on multi-access (Ethernet) links; exit-interface-only on point-to-point links.

15. Why is configuring a static route with only an exit interface on an Ethernet (multi-access) link problematic?

    The router treats every destination as directly connected and must ARP for each host, which can fail or flood ARP requests. A next-hop IP (or fully specified route) avoids this.

16. What is a host route (static) and what prefix length does it use for IPv4 and IPv6?

    A static route to a single host destination: /32 for IPv4 and /128 for IPv6 (e.g., ip route 10.1.1.5 255.255.255.255 10.0.0.2).

17. What command enables IPv6 unicast routing on a Cisco router, and why is it required?

    ipv6 unicast-routing (global config). By default a router will not forward IPv6 packets between interfaces until it is enabled.

18. Write the command to configure an IPv6 static route to 2001:db8:a::/64 via next hop 2001:db8:1::2.

    ipv6 route 2001:db8:a::/64 2001:db8:1::2

See more IP Connectivity flashcards →

Planning IP Connectivity for Cisco Certified Network Associate (CCNA)

IP Connectivity (Cisco Certified Network Associate (CCNA)) FAQ