EIGRP Hello-Interval, EIGRP Hold-Time

Lessons Learned:

Hello Interval

-how often I send hellos on a link

--ip hello-interval eigrp (AS) (Seconds)

Hold Time

Hod long you should wait to declare me down

--Opposite of OSPF hello and Dead interval

-ip hold-time eigrp (as) (seconds)

Note: The timers do not have to match for and Adjacency to form.

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The EIGRP logic is different than other protocols. In EIGRP it’s the opposite – the hello interval does control how often we are sending hello’s out an interface but he EIGRP Hold time is a value that we put inside out hello packet. This tells the remote neighbor how long to wait to declare us down.

The hold time configure on the interface is going to affect the remote neighbor, not the local neighbor.

We can view the hold timers with the command:  sh ip eigrp interface detail

R1#sh ip eigrp interfaces detail

IP-EIGRP interfaces for process 500

                        Xmit Queue   Mean   Pacing Time   Multicast    Pending

Interface        Peers  Un/Reliable  SRTT   Un/Reliable   Flow Timer   Routes

Fa0/0              2        0/0        37       0/1          168           0

  Hello interval is 5 sec  ---Hello interval is 5 seconds – Default for this interface.

  Next xmit serial <none>

  Un/reliable mcasts: 0/3  Un/reliable ucasts: 7/8

  Mcast exceptions: 2  CR packets: 2  ACKs suppressed: 0

  Retransmissions sent: 2  Out-of-sequence rcvd: 0

  Authentication mode is not set

  Use multicast

Note: default for Serial of low speed NBMA networks the default is 60 second.

For the hold timers.

For low speed NBMA networks the default is 180 seconds, where all other networks the default hold time is 15 seconds.

Configuration –

Both the timers are configured under the interface

IP hello-interval eigrp (as) (seconds)

IP hold-timer eigrp (as) (Seconds)