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Use this object to configure options for the Service Registry component within the Service Discovery framework. Currently, the SBC uses Domain Name System (DNS) servers for Service Registry.

You can add up to eight name server instances, each with its own name server index, within the configuration of a single DNS Service Registry.

For more information on how the SBC uses a DNS-based Service Discovery framework to determine IP addresses for certain services, refer to Service Discovery for Trap Target Destinations and EMS Registration. Refer to Configuring Service Discovery for Trap Target Destinations and EMS Registration for additional configuration explanations and examples.

Command Syntax

Set Command Syntax

% set system serviceDiscovery
    serviceRegistry <name_of_serviceRegistry>
      nameserver <index_of_nameserver>
        hostname <fqdn> | ipAddress <ip> port <1...65535>
        priority <0...100>
        weight <0...100>
      transport <fallback | tcp | udp | udpEdns0>
      attempts <1...x>
      timeout <100...x>
      resolve
        recurse <false | true>
        roundRobin <false | true>
        ttl <1...x>

Command Parameters

Service Registry parameters for SBC Service Discovery


Parameter

Length/Range

Description

serviceRegistry

N/A

<name_of_serviceRegistry> – The name of the Service Registry (up to 128 characters)

  • nameserver <index_of_nameserver> – Specifies the index value for the name server. Each name server instance must have a unique index number. The range allowed is 0 to 7.
    • specify a hostname or an ipAddress
      • hostname <fqdn> – Specifies an FQDN of up to 128 characters for the name server. If you specify a host name (FQDN), the IP address is resolved using the system name server assigned to the SBC management interface.
      • ipAddress <ip> – Specifies an IPv4 or IPv6 address for the name server.
        • port <port_number> – Specifies the port number to use with the IP address. The range is 1 to 65535 and the default is 53.
    • priority <priority_value> – Specifies a priority for the name server. The range is 0 to 100 and the default is 0.
    • weight <weight_value> – Specifies a weight for the name server. The range is 0 to 100 and the default is 0. (Name servers with the same priority are prioritized based on the following formula: W/SW, where W = the weight of the name server and SW = the sum of the weights of the name servers having the same priority.)
  • transport – Specifies the type of transport to use to send a request to a Service Registry name server. Select one of the following options:
    • fallback – (default) Use UDP with EDNS0, then UDP, then TCP if a response contains an error such as a truncated response.
    • tcp – Use TCP to contact a name server.
    • udp – Use UDP to contact a name server. The max message size is 512 bytes.
    • udpEdns0 – Use UDP with EDNS0 OPT RR to contact a name server. The max message size is 4096 bytes.
  • attempts <retry_attempts> – Specifies the number of retries before a request to a name server is dropped. Retries are sent using an exponential backoff delay. The range is 1 to 4294967295. The default is 1.
  • timeout <timeout_value> – Specifies a timeout, in ms, before a request to a name server times out.  The range is 100 to 4294967295. The default is 500.
  • resolve – Specifies how the resolution of a service query is managed. Options are:
    • recurse – Specifies whether the resolution of a service should be recursive. The options are:
      • False (default)
      • True
    • roundRobin – Specifies whether the order in which name servers are queried should be random. The options are:
      • False –  the SBC sends a resolve query to contact the configured name servers sequentially until the SBC receives a response.
      • True  – (default) the SBC sends a resolve query to contact the configured name servers in a random order until the SBC receives a response. The order changes for each query.
    • ttl – Specifies the maximum time-to-live, in seconds, to use when resolving an entry. The range is 1 to 4294967295. The default is 30 seconds. If the TTL of an entry in the name server is greater than this value, this value is used instead.

Command Example

The following example displays a Service Registry configuration.

% show configuration system serviceDiscovery
 
serviceRegistry SDR_primary {
    nameserver 1 {
        ipAddress 21.22.23.24;
        port      22;
        priority  1;
        weight    10;
    }
    transport tcp;
    attempts  10;
    timeout    100;
 
    resolve {
        recurse    true;
        roundRobin true;
        ttl        2;
    }
}