About domain labels
Domain label settings are located on the Administration > Networking: Domain Labels page.
Domain labels enable you to group domains for easier configuration. Add in-path rules (both optimized and pass-through rules) to a domain label to filter connections based on the hostnames included under the label. Specify internet domains with wildcards (*) to define wider groups. For example, you can create a domain label called Office365 and add *.microsoftonline.com, *.office365.com, or *.office.com. Determine all of the domains whose traffic you want to optimize, and make an entry in the domain label for each one. Domain labels are most useful when they specify a narrow destination IP range, so use the smallest destination IP range you can. Using a host label can help to narrow the destination IP range. Keep in mind that the URL might use other domains. For example, www.box.com might also use srv1.box.net and other domains.
Domain labels provide flexible domain and hostname-based interception through a dynamic IP address to accommodate network environments that are changing from static to dynamic IP addresses. For details on domain label guidelines and when to use them, see the SteelHead User Guide.
These guidelines apply to domain labels:
• Because hostname-based interception (HNBI) consumes resources, we recommend you use domain label rules that are low in the in-path rule stack.
• If the traffic matches the domain rule and HNBI fails, the system moves to the next rule that matches. If the traffic matches a fixed-target rule and HNBI fails, and the subsequent search matches an autodiscovery rule, then the traffic is bypassed.
• Domain label in-path rules that are defined as pass through, discard, or deny should be used with extreme caution as they can pass through or block all traffic.
• You must include a top-level domain: for example, .com. You cannot include a wildcard in a top-level domain.
• You must specify second-level domains: for example, *.outlook.com, but not *.com.
• A domain name can be up to 64 characters long, and wildcards (but not multiple, consecutive wildcards) are allowed. Do not use consecutive periods. Do not use IP addresses.
• A domain can appear in multiple domain labels. You can create up to 63 unique domain labels.
For general information about labels, see
About labels.