Limitations

Known limits of the system that are not obvious from the CLI or the YANG models. Each entry names the release that introduced it.

Configuration String Limits

Several settings end up verbatim in configuration files of the daemons that implement them, so their character set is restricted, since v26.09.0. A startup-config with a value outside these limits fails validation on boot, and the system falls back to failure-config, see Broken startup-config. Check the settings below before upgrading from an older release.

Setting	Allowed characters	Length
Interface name	Letters, digits, _, ., :, +, -, must start with a letter, digit, or _
Hardware component name	As interface name, @ also allowed
Keystore asymmetric key and certificate name	As interface name, @ also allowed
DHCP client option value	Letters, digits, space, _, ., :, /, @, =, ,, +, -	1..255
DHCP server static-host hostname	Letters, digits, _, ., -	1..255
DHCP server static-host client-id	Letters, digits, _, ., :, +, -	1..255
Syslog property-filter value	Letters, digits, space, _, ., :, /, @, =, ,, -, and + * ? \| ^ $ ( ) [ ] { }
Syslog file and remote pattern-match	As property-filter value
Wi-Fi mesh-id	Anything except control characters, ", and \
Wi-Fi nas-identifier	Letters, digits, _, ., :, +, -
Wi-Fi access point and mesh point passphrase	Printable characters, same rule as for station	8..63
SNMP community and security names	Anything except line breaks

The exact patterns are in the YANG models, e.g., infix-interfaces.yang for interface names. A value is rejected at leave in the CLI, or by the edit operation over NETCONF and RESTCONF, with the pattern that failed.