Courseiva
EIGRPInterface Config

ip hold-time eigrp [as] [secs]

Configures the EIGRP hold time (in seconds) for a specific EIGRP autonomous system on an interface, determining how long the router waits for a hello packet before declaring the neighbor down.

Definition: ip hold-time eigrp [as] [secs] is a Cisco IOS interface config command. Configures the EIGRP hold time (in seconds) for a specific EIGRP autonomous system on an interface, determining how long the router waits for a hello packet before declaring the neighbor down.

Overview

The `ip hold-time eigrp [as] [secs]` command is an interface-level configuration command used to set the hold time for EIGRP on a specific interface. The hold time is the duration (in seconds) that a router waits to receive a hello packet from a neighbor before declaring that neighbor as down. This command is critical for tuning EIGRP convergence and stability.

By default, EIGRP uses a hold time of three times the hello interval (15 seconds for most interfaces, 180 seconds for NBMA). Adjusting the hold time can help in scenarios where hello packets are delayed due to link congestion or high latency, preventing unnecessary neighbor resets. It is also used to speed up convergence by reducing the hold time, but this must be balanced with the risk of flapping.

The command is applied per interface and per autonomous system, allowing granular control. In the broader workflow, after configuring EIGRP and enabling it on interfaces, engineers may adjust timers to optimize performance. The command takes effect immediately and is stored in the running configuration.

It requires privileged EXEC mode to enter interface configuration mode. The hold time must be greater than the hello interval; otherwise, the router may declare neighbors down prematurely. This command is often used in conjunction with `ip hello-interval eigrp` to ensure consistent timer settings across neighbors.

Understanding the impact on convergence and stability is crucial for CCNA and CCNP candidates.

Syntax·Interface Config
ip hold-time eigrp [as] [secs]

When to Use This Command

  • Tuning convergence time on a fast link by reducing the hold time to detect failures faster.
  • Increasing hold time on a slow or congested link to prevent false neighbor loss due to delayed hello packets.
  • Matching hold time with a neighbor's hello interval to ensure consistent neighbor relationships.
  • Adjusting hold time for a specific EIGRP AS when multiple EIGRP processes run on the same interface.

Parameters

ParameterSyntaxDescription
as<1-65535>The autonomous system number for the EIGRP process. This must match the AS number configured with the `router eigrp` command. Common mistake: using a different AS number than the one used in the EIGRP configuration, which results in the command being ignored.
secs<1-65535>The hold time in seconds. Valid range is 1 to 65535. Typical values are 15 (for fast convergence) or 180 (for NBMA). Common mistake: setting the hold time less than the hello interval, which can cause neighbor flapping.

Command Examples

Set hold time to 30 seconds for AS 100

ip hold-time eigrp 100 30
R1(config-if)# ip hold-time eigrp 100 30
R1(config-if)#

The command is accepted without error. The hold time for EIGRP AS 100 on this interface is now 30 seconds. The router will wait 30 seconds without receiving a hello before declaring the neighbor down.

Verify hold time configuration

show ip eigrp 100 interface GigabitEthernet0/0
EIGRP-IPv4 Interfaces for AS(100)
                   Xmit Queue   Mean   Pacing Time   Multicast    Pending
Interface         Peers  Un/Reliable  SRTT   Un/Reliable   Flow Timer   Routes
Gi0/0              1       0/0       1200   0/0           50           0
  Hello interval: 10 sec, Hold time: 30 sec
  Next hello in: 7.432 secs

The output shows the interface Gi0/0 for EIGRP AS 100. The 'Hold time: 30 sec' confirms our configuration. The 'Hello interval: 10 sec' is the default. The hold time should be at least three times the hello interval; here 30 sec is three times 10 sec, which is standard.

Understanding the Output

The command itself produces no output beyond the CLI prompt. To verify the hold time, use 'show ip eigrp [as] interface [interface]'. In the output, look for the line 'Hold time: X sec'.

The hold time is typically three times the hello interval (default hello 5 sec, hold 15 sec; or hello 60 sec, hold 180 sec on NBMA). A hold time that is too short (e.g., equal to hello interval) can cause flapping neighbors. A hold time that is too long delays convergence.

Ensure the hold time is consistent across neighbors; mismatched hold times do not prevent adjacency but may cause issues if one side times out faster.

Configuration Scenarios

Adjust EIGRP hold time on a serial link to improve convergence

A network engineer wants to speed up EIGRP convergence on a point-to-point serial link between two routers. The default hello interval is 5 seconds and hold time is 15 seconds. To detect failures faster, the hold time is reduced to 9 seconds.

Topology

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

Steps

  1. 1.Step 1: Enter privileged EXEC mode: R1> enable
  2. 2.Step 2: Enter global configuration mode: R1# configure terminal
  3. 3.Step 3: Enter interface configuration mode: R1(config)# interface serial0/0/0
  4. 4.Step 4: Set the EIGRP hold time to 9 seconds for AS 100: R1(config-if)# ip hold-time eigrp 100 9
  5. 5.Step 5: (Optional) Adjust hello interval to 3 seconds for consistency: R1(config-if)# ip hello-interval eigrp 100 3
  6. 6.Step 6: Exit and verify: R1(config-if)# end
Configuration
!
interface Serial0/0/0
 ip address 10.0.12.1 255.255.255.252
 ip hold-time eigrp 100 9
 ip hello-interval eigrp 100 3
!

Verify: Use `show ip eigrp 100 interfaces serial0/0/0 detail` to verify the hold time. Expected output includes 'Hold time: 9'.

Watch out: If the hello interval is not also adjusted, the hold time must be at least three times the hello interval to avoid flapping. Here, 9 seconds is exactly three times the hello interval of 3 seconds.

Increase hold time on a high-latency satellite link to prevent flapping

A branch office connects via a satellite link with high latency (up to 600 ms). The default hold time of 15 seconds may cause false neighbor loss due to delayed hello packets. The hold time is increased to 60 seconds.

Topology

R1(Gi0/0)---10.0.0.0/30---(Gi0/0)R2 (satellite link)

Steps

  1. 1.Step 1: Enter privileged EXEC mode: R1> enable
  2. 2.Step 2: Enter global configuration mode: R1# configure terminal
  3. 3.Step 3: Enter interface configuration mode: R1(config)# interface gigabitethernet0/0
  4. 4.Step 4: Set the EIGRP hold time to 60 seconds for AS 200: R1(config-if)# ip hold-time eigrp 200 60
  5. 5.Step 5: (Optional) Increase hello interval to 20 seconds: R1(config-if)# ip hello-interval eigrp 200 20
  6. 6.Step 6: Exit and verify: R1(config-if)# end
Configuration
!
interface GigabitEthernet0/0
 ip address 10.0.0.1 255.255.255.252
 ip hold-time eigrp 200 60
 ip hello-interval eigrp 200 20
!

Verify: Use `show ip eigrp 200 interfaces gigabitethernet0/0 detail` to verify the hold time. Expected output includes 'Hold time: 60'.

Watch out: Increasing the hold time delays convergence. Ensure that the hello interval is also increased proportionally to maintain the 3:1 ratio, otherwise the router may still declare neighbors down if hellos are delayed beyond the hold time.

Troubleshooting with This Command

When troubleshooting EIGRP neighbor issues, the `ip hold-time eigrp` command is often a suspect. Healthy output from `show ip eigrp interfaces detail` shows the configured hold time and the actual hold time (which may differ if the neighbor advertises a different hold time). Key fields to examine are 'Hold time' (configured) and 'Uptime' of neighbors.

If neighbors are flapping, check if the hold time is too short for the link's latency. Common symptoms include 'EIGRP: Neighbor 10.0.12.2 not yet up' or 'EIGRP: Neighbor 10.0.12.2 down' messages. A diagnostic flow: 1) Check `show ip eigrp neighbors` to see if neighbors are present and their uptime. 2) If neighbors are missing, use `debug eigrp packets hello` to see if hello packets are being sent and received. 3) Verify the hold time on both ends using `show ip eigrp interfaces detail`. 4) Ensure the hold time is consistent between neighbors; mismatched hold times are allowed but the lower hold time is used. 5) Check for packet drops using `show interface` for errors. 6) If using NBMA, ensure the hold time is appropriate (default 180 seconds).

Correlate with `show ip eigrp topology` to see if routes are missing. The command `show ip eigrp traffic` can show hello packet counts. If hold time is too short, increase it; if too long, decrease it to speed convergence.

Remember that changing the hold time does not affect the hello interval; both must be tuned together. In high-latency environments, a common mistake is setting the hold time too low, causing false neighbor loss. Use `ping` with large packets to simulate delay.

The command `show ip eigrp events` can log neighbor state changes. Always verify the configuration on both sides of the link.

CCNA Exam Tips

1.

CCNA exam tip: The default hold time is three times the hello interval (15 sec for fast links, 180 sec for NBMA).

2.

CCNA exam tip: Changing the hold time does not change the hello interval; they are configured separately.

3.

CCNA exam tip: If you reduce the hold time, ensure the hello interval is also reduced proportionally to avoid neighbor flapping.

4.

CCNA exam tip: The hold time must be greater than the hello interval; otherwise, neighbors will constantly time out.

Common Mistakes

Mistake: Setting hold time equal to or less than the hello interval, causing constant neighbor resets.

Mistake: Forgetting to specify the AS number when multiple EIGRP processes exist, leading to configuration on the wrong AS.

Mistake: Not verifying the change with 'show ip eigrp interface', assuming the command took effect without checking.

ip hold-time eigrp [as] [secs] vs ip hello-interval eigrp [as] [secs]

These two commands are frequently confused because both modify EIGRP neighbor maintenance timers on an interface. The hello-interval sets the frequency of hello packets, while the hold-time controls how long the router waits without receiving a hello before declaring the neighbor down. They are designed to work together: changing one typically requires adjusting the other to maintain neighbor stability.

Aspectip hold-time eigrp [as] [secs]ip hello-interval eigrp [as] [secs]
ScopeDetermines hold time for neighbor failure detectionDetermines hello packet transmission interval
Default Value3× default hello interval (45 sec on WAN, 15 sec on LAN, unless changed)15 seconds (WAN) / 5 seconds (LAN)
RelationshipShould be ≥3× the hello interval; otherwise flapping may occurShould be ≤1/3 of the hold time for stable adjacency
Effect on ConvergenceLarger hold time delays down neighbor detection and route convergenceShorter hello interval speeds up hello failure detection indirectly (if hold time adjusted accordingly)
Configuration ModeInterface configuration, per autonomous systemInterface configuration, per autonomous system

Use ip hold-time eigrp [as] [secs] when you need to extend the neighbor failure detection time, for example over lossy or low-bandwidth links where hellos may be sporadically lost.

Use ip hello-interval eigrp [as] [secs] when you need to adjust hello packet frequency independently of the hold time, typically to reduce overhead on slow links or to speed up convergence on fast links (and then adjust hold time accordingly).

Platform Notes

In IOS-XE (e.g., 16.x), the command syntax is identical: `ip hold-time eigrp [as] [secs]` under interface configuration. However, output formatting in `show ip eigrp interfaces detail` may vary slightly; the hold time is displayed as 'Hold time' in seconds. In NX-OS, the equivalent command is `ip eigrp hold-time [secs]` under interface configuration, but note that NX-OS uses a single EIGRP instance per VRF, so the AS number is not required.

For example: `interface ethernet1/1; ip eigrp hold-time 15`. In ASA, EIGRP is not supported; the ASA uses OSPF or RIP. In IOS-XR, the command is `hold-time [seconds]` under the EIGRP interface configuration submode, e.g., `router eigrp 100; interface GigabitEthernet0/0/0/0; hold-time 15`.

There is no AS parameter because it is inherited from the router configuration. In older IOS versions (12.x), the command behaves the same but may lack some verification details. Always check the specific platform documentation for exact syntax.

Related Commands

ip hello-interval eigrp [as] [secs]

Configures the EIGRP hello interval on an interface, overriding the default hello interval for the specified autonomous system.

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.

Practice for the CCNA 200-301

Test your knowledge with practice questions covering all CCNA 200-301 exam domains.

Practice CCNA 200-301 Questions