Supported Platforms
Disabling Split Detection in a Virtual Chassis Configuration
If there is a disruption to an MX Series Virtual Chassis due to failure of a member router or one or more Virtual Chassis port links, the resulting connectivity loss can cause a split in the Virtual Chassis configuration. Split detection, which is enabled by default in an MX Series Virtual Chassis, identifies the split and minimizes further network disruption.
You can disable split detection by including the no-split-detection statement at the [edit virtual-chassis] hierarchy level. Disabling split detection can be useful in certain Virtual Chassis configurations.
For example, if the backup router fails in a two-member Virtual Chassis configuration and split detection is enabled (the default behavior), the master router takes a line-card role, and the line cards (FPCs) that do not host Virtual Chassis ports go offline. This state effectively isolates the master router and removes it from the Virtual Chassis until connectivity is restored. As a result, routing is halted and the Virtual Chassis configuration is disabled. By contrast, if the backup router fails in a two-member Virtual Chassis configuration and split detection is disabled, the master router retains mastership and maintains all of the Virtual Chassis ports, effectively resulting in a single-member Virtual Chassis consisting of only the master router.
 | Best Practice: We recommend that you disable split detection for a two-member MX Series Virtual Chassis configuration if you think the backup router is more likely to fail than the Virtual Chassis port interfaces to the backup router. Configuring redundant Virtual Chassis ports on different line cards in each member router reduces the likelihood that all Virtual Chassis port interfaces to the backup router can fail. |
To disable split detection in an MX Series Virtual Chassis:
- Specify that you want to disable the default detection
of splits in the Virtual Chassis.[edit virtual-chassis]user@gladius# set no-split-detection
- Commit the configuration.
Disabling split detection causes different results for different types of Virtual Chassis failures. For information, see Split Detection Behavior in a Virtual Chassis.
