Supported Platforms
Related Documentation
- EX, J, M, MX, PTX, QFX, T Series
- show pim neighbors in the Junos OS Routing Protocols and Policies Command Reference
Modifying the PIM Hello Interval
Routing devices send hello messages at a fixed interval on all PIM-enabled interfaces. By using hello messages, routing devices advertise their existence as PIM routing devices on the subnet. With all PIM-enabled routing devices advertised, a single designated router for the subnet is established.
When a routing device is configured for PIM, it sends a hello message at a 30-second default interval. The interval range is from 0 through 255. When the interval counts down to 0, the routing device sends another hello message, and the timer is reset. A routing device that receives no response from a neighbor in 3.5 times the interval value drops the neighbor. In the case of a 30-second interval, the amount of time a routing device waits for a response is 105 seconds.
If a PIM hello message contains the hold-time option, the neighbor timeout is set to the hold-time sent in the message. If a PIM hello message does not contain the hold-time option, the neighbor timeout is set to the default hello hold time.
To modify how often the routing device sends hello messages out of an interface:
- This example shows the configuration for the routing instance.
Configure the interface globally or in the routing instance. [edit routing-instances PIM.master protocols pim interface fe-3/0/2.0]user@host# set hello-interval 255
- Verify the configuration by checking the Hello Option Holdtime field in the output of the show pim neighbors detail command.
user@host> show pim neighbors detail
Instance: PIM.master Interface: fe-3/0/2.0 Address: 192.168.195.37, IPv4, PIM v2, Mode: Sparse Hello Option Holdtime: 255 seconds Hello Option DR Priority: 1 Hello Option LAN Prune Delay: delay 500 ms override 2000 ms Join Suppression supported Rx Join: Group Source Timeout 225.1.1.1 192.168.195.78 0 225.1.1.1 0 Interface: lo0.0 Address: 10.255.245.91, IPv4, PIM v2, Mode: Sparse Hello Option Holdtime: 255 seconds Hello Option DR Priority: 1 Hello Option LAN Prune Delay: delay 500 ms override 2000 ms Join Suppression supported Interface: pd-6/0/0.32768 Address: 0.0.0.0, IPv4, PIM v2, Mode: Sparse Hello Option Holdtime: 255 seconds Hello Option DR Priority: 0 Hello Option LAN Prune Delay: delay 500 ms override 2000 ms Join Suppression supported
Related Documentation
- EX, J, M, MX, PTX, QFX, T Series
- show pim neighbors in the Junos OS Routing Protocols and Policies Command Reference
Published: 2012-06-27
Supported Platforms
Related Documentation
- EX, J, M, MX, PTX, QFX, T Series
- show pim neighbors in the Junos OS Routing Protocols and Policies Command Reference