After a power cycle, SRX5800 did not manage to activate its MNHA configuration. Only after a subsequent reboot was the MNHA function (configuration) properly activated.

SRX was showing the below error while checking the MNHA status.

user@srx5800> show chassis high-availability information 
Jun 24 18:39:30
error: chassis high-availability mode not configured.

The customer performed the below steps that led to this issue.

1. The Customer powered down the SRX that had MNHA enabled and replaced the existing RE with a different RE. The new one did not have any MNHA configuration.

2. The customer ran the command "request system zeroize" which led to the SRX reboot.

3. Post that customer Powered Down the SRX and then placed the old RE back. When it came up MNHA was not enabled and a subsequent reboot was required to fix it.

When configuring High Availability (HA) on systems, specific sysctl settings must be programmed to activate HA functionality. This configuration requires a system reboot to take effect. The status of HA configuration can be verified by checking the sysctl variable using the command sysctl hw.re.l3_ha_mode_enabled. If the sysctl setting is not programmed for HA, the command returns a value of 0. If HA is enabled, it returns a value of 3.

The HA state value is stored in the EEPROM on the SCB board. The sequence of operations involving the EEPROM and HA state configuration is as follows:

System Boot and HA Mode Read:

• After the system boots and the RE kernel is operational, jsrpd reads the HA mode configuration.

• jsrpd writes any changes in HA mode to the EEPROM on the SCB board.

Reboot Requirement:

• For the kernel to read the updated HA mode from the EEPROM and set the kernel HA state, a system reboot is necessary. That is the reason we need to do a reboot after configuring the MNHA.

Changes that happened in each step when the customer performed the steps that created the issue.

1. The SRX device with an RE configured for MNHA was displaying sysctl hw.re.l3_ha_mode_enabled as 3, indicating that MNHA was enabled.

2. The SRX was powered down, and the existing RE was replaced with a different RE that had no MNHA configuration. Upon powering up, the device still showed sysctl hw.re.l3_ha_mode_enabled as 3 because this value was read from the EEPROM.

3. The customer ran the command "request system zeroize", causing the SRX to reboot. After rebooting, the device showed sysctl hw.re.l3_ha_mode_enabled as 0, reflecting the lack of MNHA configuration on the new RE.

4. The SRX was powered down again, and the old RE (which initially had MNHA configuration) was reinstalled. Upon rebooting, MNHA was not enabled as sysctl hw.re.l3_ha_mode_enabled now read 0 from the EEPROM.

To restore MNHA, an additional reboot was required after placing the old RE back in the system.

The HA state value, once set by an RE with MNHA configuration, is stored in the EEPROM. If the RE is replaced with one that lacks MNHA configuration, the system will still read the previous value from the EEPROM until a reboot or system zeroize command updates it. This behavior necessitates careful management of reboots and configuration checks to ensure the desired HA state is maintained.