🛣️ IP Routing & Protocols - CCNA Practice Questions

CCNA Routing Question Bank (10 Questions)

Browse all 10 practice questions covering IP Routing & Protocols for the CCNA certification exam. Each question includes the full answer and a detailed explanation to help you understand the concepts.

1. Question 1IP Connectivity

   What is the purpose of a default route (0.0.0.0/0) in a routing table?

   ATo block all traffic

   BTo forward packets to a next hop when no more specific route matches the destination — the 'gateway of last resort'✓

   CTo route traffic to the loopback interface

   DTo enable DHCP
   Show Answer & Explanation

   Correct Answer: B

   Explanation:

   Default route (0.0.0.0/0) matches any destination with 0 prefix bits — it's the least specific route. Used when no other route matches. Typically points toward the internet gateway or ISP. 'ip route 0.0.0.0 0.0.0.0 <next-hop>' or learned via routing protocol.

2. Question 2IP Connectivity

   Which symbol in a Cisco routing table indicates a directly connected network?

   AS

   BO

   CC✓

   DR
   Show Answer & Explanation

   Correct Answer: C

   Explanation:

   C = Connected (directly attached), S = Static, O = OSPF, R = RIP, D = EIGRP, B = BGP.

3. Question 3IP Connectivity

   A router has the following routes in its routing table: - 10.1.0.0/16 via 192.168.1.1 - 10.1.1.0/24 via 192.168.1.2 - 10.1.1.128/25 via 192.168.1.3 A packet arrives destined for 10.1.1.200. Which next-hop will the router use?

   A192.168.1.1

   B192.168.1.2

   C192.168.1.3✓

   DThe packet will be dropped
   Show Answer & Explanation

   Correct Answer: C

   Explanation:

   Routers use the longest prefix match algorithm. The address 10.1.1.200 matches all three routes, but 10.1.1.128/25 (which covers 10.1.1.128–10.1.1.255) is the most specific match with a /25 prefix. The /24 covers 10.1.1.0–10.1.1.255 and /16 covers the entire 10.1.x.x range. The longest match (/25) wins.

4. Question 4IP Connectivity

   What happens when a router cannot find a matching entry in its routing table for a destination IP address and no default route exists?

   AThe router floods the packet out all interfaces

   BThe router drops the packet and may send an ICMP Destination Unreachable message to the source✓

   CThe router buffers the packet indefinitely until a route appears

   DThe router sends the packet to the first interface in its configuration
   Show Answer & Explanation

   Correct Answer: B

   Explanation:

   When a router has no matching route (including no default route), it drops the packet and typically sends an ICMP Type 3 (Destination Unreachable) message back to the source. Routers do not flood packets — that is a switch behavior for unknown unicast frames.

5. Question 5IP Connectivity

   Which type of static route uses the outgoing interface as the next hop?

   ARecursive static route

   BDirectly connected static route✓

   CFloating static route

   DDefault static route
   Show Answer & Explanation

   Correct Answer: B

   Explanation:

   A directly connected static route specifies the exit interface instead of a next-hop IP. A recursive static route specifies a next-hop IP that requires another lookup.

6. Question 6IP Connectivity

   Which routing protocol has the lowest default administrative distance?

   AOSPF

   BEIGRP✓

   CRIP

   DIS-IS
   Show Answer & Explanation

   Correct Answer: B

   Explanation:

   EIGRP has a default AD of 90, OSPF is 110, IS-IS is 115, and RIP is 120. Lower AD is preferred.

7. Question 7IP Connectivity

   Which command creates a default static route for IPv4?

   Aip route 0.0.0.0 0.0.0.0 10.1.1.1✓

   Bip route 255.255.255.255 0.0.0.0 10.1.1.1

   Cip default-network 10.1.1.0

   Dip route 0.0.0.0 255.255.255.255 10.1.1.1
   Show Answer & Explanation

   Correct Answer: A

   Explanation:

   The command 'ip route 0.0.0.0 0.0.0.0 <next-hop>' creates a default route (gateway of last resort) matching all destinations.

8. Question 8IP Connectivity

   What command verifies the routing table on a Cisco router?

   Ashow interfaces

   Bshow ip route — displays all known routes including connected, static, and dynamically learned routes with next hop and outgoing interface✓

   Cshow arp

   Dshow mac address-table
   Show Answer & Explanation

   Correct Answer: B

   Explanation:

   'show ip route' displays: route source codes (C=connected, S=static, O=OSPF, D=EIGRP, B=BGP), destination networks, admin distance/metric [AD/metric], next-hop IP, exit interface, and route age. Essential for verifying routing decisions and troubleshooting.

9. Question 9IP Connectivity

   If a router learns the same destination via OSPF (AD 110) and EIGRP (AD 90), which route is installed?

   AOSPF (lower number always loses)

   BEIGRP — lower administrative distance (90) is preferred over OSPF (110), indicating higher trustworthiness✓

   CBoth routes are installed for load balancing

   DThe route learned first
   Show Answer & Explanation

   Correct Answer: B

   Explanation:

   Administrative Distance determines route preference between different routing sources. Lower AD = more trusted. Common ADs: Connected (0), Static (1), EIGRP (90), OSPF (110), IS-IS (115), RIP (120), External EIGRP (170), iBGP (200). EIGRP's 90 beats OSPF's 110.

10. Question 10IP Connectivity

    What is the administrative distance of an OSPF-learned route on a Cisco router?

    A90

    B100

    C110✓

    D120
    Show Answer & Explanation

    Correct Answer: C

    Explanation:

    OSPF has a default administrative distance (AD) of 110 on Cisco routers. EIGRP internal routes have AD 90, EIGRP external has AD 170, RIP has AD 120, static routes have AD 1 (or 0 for connected), and eBGP has AD 20.