show ip eigrp neighbors
Displays the neighbor table for EIGRP, showing all directly connected EIGRP routers and their status, used to verify EIGRP adjacencies and troubleshoot neighbor relationships.
show ip eigrp neighborsWhen to Use This Command
- Verify that EIGRP adjacencies have formed correctly after configuring EIGRP on a new router.
- Troubleshoot why routes are not being exchanged by checking if neighbors are in the Established state.
- Monitor neighbor uptime and hold time to detect flapping or unstable links.
- Check the source interface and address of EIGRP neighbors for verification of network design.
Command Examples
Basic EIGRP Neighbor Display
show ip eigrp neighborsEIGRP-IPv4 Neighbors for AS(100)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 192.168.1.2 GigabitEthernet0/0 13 00:12:34 1 200 0 12
1 10.0.0.2 Serial0/0/0 12 00:10:22 2 200 0 8H: Neighbor handle number (0-indexed). Address: Neighbor's IP address. Interface: Local interface through which the neighbor is reachable. Hold: Current hold time in seconds (should be >0; if 0, neighbor is considered down). Uptime: Time since adjacency was established. SRTT: Smooth Round Trip Time in ms (low values indicate good link). RTO: Retransmission Timeout in ms (should be low). Q Cnt: Queue count (should be 0; non-zero indicates packets waiting to be sent). Seq Num: Sequence number of the last EIGRP packet received from this neighbor.
Display EIGRP Neighbors for a Specific AS
show ip eigrp 200 neighborsEIGRP-IPv4 Neighbors for AS(200)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 172.16.0.1 GigabitEthernet0/1 14 01:05:00 5 300 0 25This example shows neighbors only for EIGRP autonomous system 200. The output format is identical to the basic command, but filtered by AS. Note the longer uptime and higher SRTT compared to the first example, indicating a stable but slightly higher-latency link.
Understanding the Output
The 'show ip eigrp neighbors' command displays the EIGRP neighbor table. Each row represents a directly connected EIGRP router. The 'H' column is a handle number assigned by the router. 'Address' is the neighbor's IP address used for EIGRP communication. 'Interface' is the local interface connecting to the neighbor. 'Hold' is the remaining time in seconds before the neighbor is declared dead (default hold time is 15 seconds; values near 15 are healthy, values near 0 indicate imminent loss). 'Uptime' shows how long the adjacency has been established (HH:MM:SS). 'SRTT' (Smooth Round Trip Time) is the average time for a packet to travel to the neighbor and back; low values (e.g., 1-10 ms) indicate a fast link, while high values may indicate congestion or long distance. 'RTO' (Retransmission Timeout) is the time the router waits before retransmitting an unacknowledged packet; it is derived from SRTT. 'Q Cnt' (Queue Count) should be 0; if non-zero, packets are queued for transmission, possibly due to congestion or slow neighbor. 'Seq Num' is the sequence number of the last EIGRP packet received from the neighbor; it increments with each packet. In a healthy network, all neighbors should show hold times > 0, uptimes increasing, SRTT and RTO low, Q Cnt 0, and Seq Num incrementing. Watch for neighbors that appear and disappear (flapping), high SRTT/RTO, or non-zero Q Cnt, which indicate problems.
CCNA Exam Tips
CCNA exam tip: The 'show ip eigrp neighbors' command is used to verify that EIGRP adjacencies have formed. If a neighbor is missing, check that both routers are configured with the same autonomous system number and that interfaces are not passive.
CCNA exam tip: The Hold column should be between 1 and 15 seconds. A value of 0 means the neighbor is down. The exam may ask what a hold time of 0 indicates.
CCNA exam tip: The Q Cnt (Queue Count) should always be 0. A non-zero value indicates that EIGRP packets are queued and not being sent, often due to a congested link or a neighbor that is not responding.
CCNA exam tip: The SRTT and RTO values help determine link quality. Low SRTT (e.g., 1 ms) is good; high SRTT (e.g., 5000 ms) indicates a slow or congested link. The exam may test your ability to interpret these values.
Common Mistakes
Mistake 1: Assuming that a neighbor appearing in the output means routes are being exchanged. The neighbor must be in the Established state (Hold > 0) and the adjacency must be fully formed. Check also that routes are present in the topology table.
Mistake 2: Forgetting to specify the AS number when multiple EIGRP processes are running. Without the AS number, the command shows neighbors for all processes, which can be confusing.
Mistake 3: Misinterpreting the 'Hold' column as the hold time configured on the neighbor. It is the remaining time before the local router considers the neighbor down, not the configured hold time.
Related Commands
show ip eigrp interfaces
Displays detailed information about interfaces on which EIGRP is enabled, including neighbor status, pending routes, and interface statistics, used to verify EIGRP adjacency and interface participation.
show ip eigrp topology
Displays the EIGRP topology table, showing all learned routes and their feasible successors, used to verify EIGRP convergence and path selection.
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