# [UI_FFP_INVALID_HOSTNAME_ERROR](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR)

## SYSLOG Details
- **Message**: Invalid hostname - '<variable>message</variable>', Underscore not allowed in hostname
- **Help**: Invalid hostname: underscore (_) not allowed in hostname
- **Description**: Check if hostname contains underscore (_) character
- **Type**: Error: An error occurred
- **Severity**: error
- **Cause**: -
- **Action**: -
- **Attributes**: message
- **Facility**: ANY

## Found this message in the following releases:
- [Junos OS Evolved 26.2R1](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=26.2R1)
- [Junos OS Evolved 25.4R1](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=25.4R1)
- [Junos OS Evolved 25.2R2](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=25.2R2)
- [Junos OS Evolved 25.2R1](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=25.2R1)
- [Junos OS Evolved 24.4R2](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=24.4R2)
- [Junos OS Evolved 24.4R1](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=24.4R1)
- [Junos OS Evolved 24.2R1](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=24.2R1)
- [Junos OS Evolved 23.4R2](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=23.4R2)
- [Junos OS Evolved 23.4R1](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=23.4R1)
- [Junos OS Evolved 23.2R2](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=23.2R2)
- [Junos OS Evolved 23.2R1](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=23.2R1)
- [Junos OS Evolved 22.4R3](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=22.4R3)
- [Junos OS Evolved 22.2R3](https://apps.juniper.net/syslog-explorer/?msg=UI_FFP_INVALID_HOSTNAME_ERROR&sw=Junos%20OS%20Evolved&rel=22.2R3)