In which configuration mode is show ip eigrp interfaces used?

The show ip eigrp interfaces command is entered in Privileged EXEC mode on Cisco IOS devices.

EIGRPPrivileged EXEC

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.

Definition: show ip eigrp interfaces is a Cisco IOS privileged exec command. 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.

Overview

The 'show ip eigrp interfaces' command is a critical diagnostic tool for network engineers working with EIGRP (Enhanced Interior Gateway Routing Protocol). It provides a detailed view of all interfaces on which EIGRP is enabled, including their current state, neighbor relationships, and various statistics. This command is essential for verifying that EIGRP adjacencies are forming correctly, troubleshooting neighbor issues, and understanding the operational status of EIGRP on a router.

EIGRP is a distance-vector routing protocol that uses the Diffusing Update Algorithm (DUAL) to ensure loop-free and fast convergence. It operates by forming neighbor relationships with directly connected routers that also run EIGRP, exchanging routing information, and maintaining a topology table. The 'show ip eigrp interfaces' command reveals which interfaces are participating in the EIGRP process, the number of neighbors on each interface, the pending routes (routes waiting to be processed), and the queue counts for reliable and unreliable transmissions. This information is vital for assessing the health of EIGRP adjacencies and identifying potential bottlenecks or misconfigurations.

Network engineers typically reach for this command when troubleshooting EIGRP neighbor issues, such as when a neighbor is not forming or is flapping. It helps determine if an interface is correctly configured for EIGRP and if there are any problems with packet delivery (e.g., high retransmission counts). Alternatives like 'show ip eigrp neighbors' provide a more concise view of neighbor relationships, while 'show ip eigrp topology' focuses on the routing table. However, 'show ip eigrp interfaces' offers a unique blend of interface-level statistics and neighbor counts, making it the go-to command for initial EIGRP interface diagnostics.

In a broader troubleshooting workflow, this command is often used after verifying basic connectivity (ping) and EIGRP configuration (router eigrp, network statements). It can be followed by 'debug eigrp packets' or 'show ip eigrp traffic' for deeper analysis. The command runs in privileged EXEC mode (enable) and does not modify the running configuration. Its output can be lengthy on routers with many interfaces, so it may be filtered with parameters like 'show ip eigrp interfaces [interface-type number]' or piped to 'include' or 'section' commands. Understanding the output fields—such as 'Peers', 'Pending Routes', 'Q Count', and 'Mean SRTT'—is key to effective troubleshooting.

Syntax·Privileged EXEC

show ip eigrp interfaces

When to Use This Command

Verify which interfaces are participating in EIGRP and check for any passive interfaces that should be active.
Troubleshoot EIGRP neighbor adjacency issues by checking interface status and hello/hold timers.
Monitor EIGRP traffic statistics on an interface to detect excessive packet loss or retransmissions.
Confirm that EIGRP is enabled on the correct interfaces after configuration changes.

Parameters

Parameter	Syntax	Required	Description
interface-type number	e.g., GigabitEthernet0/0	Optional	Specifies a particular interface to display EIGRP information for. If omitted, all EIGRP-enabled interfaces are shown. Common mistake: using an interface that is not EIGRP-enabled, which results in no output.
AS-number	<1-65535>	Optional	The EIGRP autonomous system number. If multiple EIGRP processes are running, this parameter filters output for a specific AS. Valid range is 1-65535. Common mistake: forgetting to specify the AS when multiple processes exist, leading to ambiguous output.

Command Examples

Basic show ip eigrp interfaces

show ip eigrp interfaces

EIGRP interfaces for process 100
                        Xmit Queue   Mean   Pacing Time   Multicast    Pending
Interface        Peers  Un/Reliable  SRTT   Un/Reliable   Flow Timer   Routes
Gi0/0              1        0/0       12       0/10         50           0
Gi0/1              0        0/0       0        0/10         50           0
Se0/0/0            1        0/0       25       0/10         100          0

Interface: The router interface name. Peers: Number of EIGRP neighbors on that interface. Xmit Queue Un/Reliable: Number of packets waiting in the unreliable/reliable transmit queue (should be low). Mean SRTT: Smooth Round Trip Time in milliseconds (lower is better). Pacing Time Un/Reliable: Time between packet transmissions for unreliable/reliable packets. Multicast Flow Timer: Time in milliseconds to wait before sending multicast packets. Pending Routes: Number of routes waiting to be sent to neighbors (should be 0 in steady state).

Show ip eigrp interfaces detail

show ip eigrp interfaces detail

EIGRP interfaces for process 100

Interface: GigabitEthernet0/0
  Mtu: 1500
  Bandwidth: 1000000 Kbit
  Delay: 10 usec
  Reliability: 255/255
  Load: 1/255
  Nbrs: 1
  Hello: 5 sec
  Hold: 15 sec
  Xmit Queue Un/Reliable: 0/0
  Mean SRTT: 12 ms
  Pacing Time Un/Reliable: 0/10 ms
  Multicast Flow Timer: 50 ms
  Pending Routes: 0

Interface: GigabitEthernet0/1
  Mtu: 1500
  Bandwidth: 100000 Kbit
  Delay: 100 usec
  Reliability: 255/255
  Load: 128/255
  Nbrs: 0
  Hello: 5 sec
  Hold: 15 sec
  Xmit Queue Un/Reliable: 0/0
  Mean SRTT: 0 ms
  Pacing Time Un/Reliable: 0/10 ms
  Multicast Flow Timer: 50 ms
  Pending Routes: 0

This detail output adds interface bandwidth, delay, reliability, load, MTU, and hello/hold timers. Bandwidth and delay are used for metric calculation. Reliability and load are dynamic values (255/255 is best). Hello and Hold timers must match between neighbors. High load (e.g., 128/255) may indicate congestion. No neighbors on Gi0/1 suggests a problem if adjacency is expected.

Understanding the Output

The 'show ip eigrp interfaces' command output lists each interface running EIGRP. Key columns: Interface (name), Peers (number of established neighbors; 0 means no adjacency), Xmit Queue Un/Reliable (should be low; high values indicate congestion or slow neighbor), Mean SRTT (smooth round-trip time; high values suggest slow link), Pacing Time (time between packet sends; default values are normal), Multicast Flow Timer (time to wait before sending multicast; default is fine), Pending Routes (should be 0; non-zero means routes are being exchanged). In the detail view, Bandwidth and Delay are used for metric calculation; lower delay and higher bandwidth yield better metric.

Reliability (255/255 is perfect) and Load (1/255 is low) indicate link quality. Hello and Hold timers must match between neighbors. Watch for interfaces with 0 peers if adjacency is expected, or high pending routes indicating convergence issues.

Configuration Scenarios

Verify EIGRP adjacency on a point-to-point link

Two routers are connected via a serial link and EIGRP is configured. The engineer needs to confirm that the adjacency is up and that the interface is participating correctly.

Topology

R1(Se0/0/0)---10.0.12.0/30---(Se0/0/0)R2

Steps

1.Step 1: Enter privileged EXEC mode on R1: enable
2.Step 2: Run the command: show ip eigrp interfaces Serial0/0/0
3.Step 3: Check the output for the interface Serial0/0/0. Verify that 'Peers' is 1 (indicating one neighbor), 'Pending Routes' is 0, and 'Q Count' is 0.
4.Step 4: If the interface is not listed, verify EIGRP configuration with 'show running-config | section router eigrp'.

Configuration

! R1 configuration
interface Serial0/0/0
 ip address 10.0.12.1 255.255.255.252
 no shutdown
!
router eigrp 100
 network 10.0.12.0 0.0.0.3
!

Verify: show ip eigrp interfaces Serial0/0/0 Expected output: Interface Peers Pending Routes Q Count Mean SRTT Se0/0/0 1 0 0 1

Watch out: Ensure the interface is not in a down state. Also, if the link is using a different encapsulation (e.g., HDLC vs PPP), EIGRP may still work, but mismatched MTU can cause adjacency issues.

Troubleshoot EIGRP neighbor flapping on a multi-access network

A router on an Ethernet segment has multiple EIGRP neighbors that are flapping. The engineer uses 'show ip eigrp interfaces' to identify the problematic interface and check for high retransmission counts.

Topology

R1(Gi0/0)---192.168.1.0/24---(Gi0/0)R2, (Gi0/0)R3

Steps

1.Step 1: Enter privileged EXEC mode on R1: enable
2.Step 2: Run: show ip eigrp interfaces GigabitEthernet0/0
3.Step 3: Examine the 'Q Count' and 'Mean SRTT' fields. A high Q Count (e.g., >10) or high Mean SRTT (e.g., >1000 ms) indicates packet loss or congestion.
4.Step 4: Check the 'Pending Routes' field. If it is non-zero, the router is still processing updates, which may indicate a slow CPU or excessive routing changes.
5.Step 5: Correlate with 'show ip eigrp neighbors' to see if neighbors are in 'Init' or 'Down' state.

Configuration

! R1 configuration
interface GigabitEthernet0/0
 ip address 192.168.1.1 255.255.255.0
 no shutdown
!
router eigrp 100
 network 192.168.1.0
!

Verify: show ip eigrp interfaces GigabitEthernet0/0 Expected output (healthy): Interface Peers Pending Routes Q Count Mean SRTT Gi0/0 2 0 0 10 If flapping, Q Count may be high or Peers may be 0.

Watch out: On multi-access networks, ensure that the 'ip hello-interval eigrp' and 'ip hold-time eigrp' are consistent across all routers. Also, check for duplex mismatches or excessive collisions.

Troubleshooting with This Command

When using 'show ip eigrp interfaces' for troubleshooting, focus on key fields: 'Peers', 'Pending Routes', 'Q Count', and 'Mean SRTT'. A healthy interface should show 'Peers' equal to the number of expected neighbors, 'Pending Routes' as 0 (indicating no routes waiting to be processed), 'Q Count' as 0 (no packets queued for transmission), and 'Mean SRTT' (Smoothed Round Trip Time) typically under 100 ms for LAN links.

Common symptoms and their indicators: - **No neighbors listed**: The interface may not be EIGRP-enabled, or the network statement is missing. Check configuration with 'show running-config | section router eigrp'. Also verify that the interface is up/up. - **High Q Count**: Indicates that EIGRP packets are queued and not being sent quickly. This could be due to congestion, high CPU, or a slow link. Check interface statistics with 'show interfaces' for drops or errors. - **High Mean SRTT**: Suggests high latency on the link, which can cause neighbor flapping if the hold time is exceeded. Compare with the configured hold time (default 15 seconds). - **Non-zero Pending Routes**: The router is still processing updates. This may be normal during convergence but should settle. If persistent, it could indicate a routing loop or excessive route churn.

Diagnostic flow: 1. Start with 'show ip eigrp interfaces' to get an overview of all EIGRP-enabled interfaces. 2. If an interface shows problems, drill down with 'show ip eigrp interfaces [interface]' for specific details. 3. Check neighbor state with 'show ip eigrp neighbors' to see if neighbors are in 'Up' state. 4. If neighbors are flapping, examine 'show ip eigrp traffic' for packet statistics and errors. 5. Use 'debug eigrp packets' (with caution) to see real-time packet exchange. 6. Correlate with 'show interfaces' for physical layer issues (errors, drops, duplex).

Remember that 'show ip eigrp interfaces' only shows interfaces that are actively participating in EIGRP. If an interface is missing, verify the network statement and that the interface is not passive (use 'show ip protocols' to check). Also, the command output is sorted by interface name; use 'show ip eigrp interfaces | include <pattern>' to filter.

CCNA Exam Tips

CCNA exam tip: The 'show ip eigrp interfaces' command does not show the EIGRP router ID; use 'show ip eigrp topology' or 'show ip protocols' for that.

CCNA exam tip: If an interface shows 0 peers but EIGRP is configured, check for passive-interface configuration or mismatched AS numbers.

CCNA exam tip: The 'Pending Routes' field should be 0 in a stable network; non-zero indicates routes are still being exchanged or there is a problem.

CCNA exam tip: Remember that EIGRP uses multicast address 224.0.0.10; if the interface is not receiving hellos, check ACLs or switchport settings.

Common Mistakes

Mistake 1: Assuming 'show ip eigrp interfaces' shows all interfaces on the router; it only shows interfaces with EIGRP enabled.

Mistake 2: Confusing 'Pending Routes' with routes in the routing table; pending routes are those not yet sent to neighbors.

Mistake 3: Forgetting that the detail output includes metric components (bandwidth, delay) which are used for route selection; misinterpreting these values can lead to incorrect troubleshooting.

show ip eigrp interfaces vs show ip eigrp topology

Both 'show ip eigrp interfaces' and 'show ip eigrp topology' are key EIGRP verification commands, often confused because they both display EIGRP-related information. However, they focus on different layers: interfaces details versus the route topology table.

Aspect	show ip eigrp interfaces	show ip eigrp topology
Scope	Interfaces with EIGRP enabled	EIGRP topology table entries
Primary Information	Interface status, neighbor adjacencies, packet stats	Routes, metrics, feasible successors, FD/AD
Typical Use	Verify EIGRP is active on an interface and neighbor reachable	Verify route learning, metric calculation, and path selection
Key Fields	Interface, IP address, peers, queues, uptime	Network, nexthop, metric, FD/AD, successors
Troubleshooting Focus	Layer 2/Layer 3 interface and neighbor issues	Route instability, suboptimal paths, convergence

Use show ip eigrp interfaces when you need to confirm that EIGRP adjacencies are formed and interfaces are participating properly.

Use show ip eigrp topology when you need to examine the routes EIGRP has learned, verify feasible successors, or troubleshoot path selection and metric issues.

Platform Notes

In IOS-XE (e.g., Catalyst 9000 switches), the command syntax and output are identical to classic IOS. However, on some IOS-XE platforms, the output may include additional fields like 'Hello Interval' and 'Hold Time' if configured non-default. The command is available in privileged EXEC mode (enable) and does not require any special privilege level beyond 15.

In NX-OS (Cisco Nexus switches), the equivalent command is 'show ip eigrp interfaces' but with slightly different output formatting. NX-OS also supports 'show ip eigrp neighbors' and 'show ip eigrp topology'. The command works in the default VDC; for non-default VDCs, you must be in the correct VDC context.

For ASA firewalls, EIGRP is not supported; ASAs use OSPF or RIP. Therefore, this command does not exist on ASA platforms.

In IOS-XR (Cisco ASR 9000, CRS), the command is 'show eigrp interfaces' (without 'ip'). The output format is different, and the command is executed in XR EXEC mode. For example: 'show eigrp interfaces brief' provides a summary. Note that IOS-XR uses a different configuration model (EIGRP is configured under 'router eigrp' with address-family).

Across IOS versions (12.x, 15.x, 16.x), the command has remained consistent. In older versions (12.x), the output may not include the 'Pending Routes' field. Always check the specific IOS documentation for your version. The command is not affected by the 'service timestamps' or 'logging' commands.

Related Commands

show ip eigrp neighbors

Displays all EIGRP neighbours with their addresses, interfaces, hold time, uptime, SRTT (smooth round-trip time), RTO, queue count, and sequence numbers.

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.

show ip protocols

Displays the current state of all IP routing protocols running on the router, including timers, filters, and network advertisements.

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