Network Management

Unable to Create Netpath Service with _ in its name

When entering a DNS name with _ in it into the Netpath hostname section it will not allow you to save it. Netpath will not work with _ in the name of the service to monitor

First published date

2/1/2020 12:49 AM

Last published date

3/20/2020 1:54 AM

Overview

Netpath can use either a IPv4 address or a Hostname for creating a netpath service for monitoring. Netpath does not support using DNS names, only Hostnames or IPv4 addresses.

Product section

Network Performance Monitor

Cause

Hostnames do not allow the _ character in them. Hostname's may only contain ASCII letters, digits and the hyphen.

Please see the following Stackoverflow post for further information: https://stackoverflow.com/questions/2180465/can-domain-name-subdomains-have-an-underscore-in-it
Direct except from above post:

RFC 5890 introduces the term LDH (Letter-Digit-Hypen) label for labels used in hostnames and says:

This is the classical label form used, albeit with some additional restrictions, in hostnames (RFC 952). Its syntax is identical to that described as the "preferred name syntax" in Section 3.5 of RFC 1034 as modified by RFC 1123. Briefly, it is a string consisting of ASCII letters, digits, and the hyphen with the further restriction that the hyphen cannot appear at the beginning or end of the string. Like all DNS labels, its total length must not exceed 63 octets.

Going back to simpler times, this Internet draft is an early proposal for hostname internationalization. Hostnames with international characters may be encoded using, for example, 'RACE' encoding.

The author of the 'RACE encoding' proposal notes:

According to RFC 1035, host parts must be case-insensitive, start and end with a letter or digit, and contain only letters, digits, and the hyphen character ("-"). This, of course, excludes any internationalized characters, as well as many other characters in the ASCII character repertoire. Further, domain name parts must be 63 octets or shorter in length.... All post-converted name parts that contain internationalized characters begin with the string "bq--". (...) The string "bq--" was chosen because it is extremely unlikely to exist in host parts before this specification was produced.

(© 2020 Stack Exchange Inc, available at https://stackoverflow.com/questions/2180465/can-domain-name-subdomains-have-an-underscore-in-it, obtained on 01/31/20)

Disclaimer: Please note, any content posted herein is provided as a suggestion or recommendation to you for your internal use. This is not part of the SolarWinds software or documentation that you purchased from SolarWinds, and the information set forth herein may come from third parties. Your organization should internally review and assess to what extent, if any, such custom scripts or recommendations will be incorporated into your environment. You elect to use third party content at your own risk, and you will be solely responsible for the incorporation of the same, if any.

Resolution

Netpath strictly enforces the following of the hostname standard outlined by RFC 952 and RFC 1123. Which includes not allowing _ in the hostname.
Please create an alias or CName record that follows the guide lines for a hostname that can be forwarded to your desired endpoint (DNS entry)

Disclaimer: Please note, any content posted herein is provided as a suggestion or recommendation to you for your internal use. This is not part of the SolarWinds software or documentation that you purchased from SolarWinds, and the information set forth herein may come from third parties. Your organization should internally review and assess to what extent, if any, such custom scripts or recommendations will be incorporated into your environment. You elect to use third-party content at your own risk, and you will be solely responsible for the incorporation of the same if any.