udpated the summary document for of i discovery service.

Author: abishekve

ThingConnect.Pulse.Server/Services/Monitoring/DiscoveryService.cs

@@ -253,26 +253,25 @@ public async Task<IEnumerable<string>> ResolveHostnameAsync(string hostname, Can
 
             if (IPAddress.TryParse(host, out var ip))
             {
+                // Expand IPv6 host into compressed and full forms
                 if (ip.AddressFamily == AddressFamily.InterNetworkV6)
-                {
-                    // Expand IPv6 host into compressed and full forms
                     hosts.AddRange(ExpandIPv6Host(host));
-                }
                 else
-                {
                     hosts.Add(host); // IPv4
-                }
             }
             else
             {
+                // Hostname
                 IEnumerable<string> resolvedHosts = await ResolveHostnameAsync(host, cancellationToken);
-                foreach (var resolvedHost in resolvedHosts)
+                hosts.AddRange(resolvedHosts.SelectMany(resolvedHost =>
                 {
-                    if (IPAddress.TryParse(resolvedHost, out var resolvedIp) && resolvedIp.AddressFamily == AddressFamily.InterNetworkV6)
-                        hosts.AddRange(ExpandIPv6Host(resolvedHost));
-                    else
-                        hosts.Add(resolvedHost);
-                }
+                    if (IPAddress.TryParse(resolvedHost, out var resolvedIp) &&
+                        resolvedIp.AddressFamily == AddressFamily.InterNetworkV6)
+                    {
+                        return ExpandIPv6Host(resolvedHost);
+                    }
+                    return new[] { resolvedHost };
+                }));
             }
         }
         else if (target.cidr != null)

ThingConnect.Pulse.Server/Services/Monitoring/IDiscoveryService.cs

@@ -2,33 +2,33 @@ namespace ThingConnect.Pulse.Server.Services.Monitoring;
 
 /// <summary>
 /// Service for expanding CIDR ranges, wildcards, and hostnames into individual endpoints.
+/// Supports both IPv4 and IPv6.
 /// </summary>
 public interface IDiscoveryService
 {
     /// <summary>
-    /// Expands a CIDR range (e.g., "10.0.0.0/24") into individual IP addresses.
+    /// Expands a CIDR range (IPv4 or IPv6) into individual IP addresses.
+    /// For IPv6, expansion is limited to /128, /127, or /64 to avoid massive expansion.
     /// </summary>
-    /// <returns></returns>
     IEnumerable<string> ExpandCidr(string cidr);
 
     /// <summary>
-    /// Expands a wildcard IP (e.g., "10.0.0.*") into individual IP addresses.
-    /// Default range: 1-254 for the wildcard octet.
+    /// Expands a wildcard IPv4 address (e.g., "10.0.0.*") into individual IP addresses.
+    /// Default range for the wildcard octet: 1-254.
     /// </summary>
-    /// <returns></returns>
     IEnumerable<string> ExpandWildcard(string wildcard, int startRange = 1, int endRange = 254);
 
     /// <summary>
-    /// Resolves a hostname to its IP addresses.
+    /// Resolves a hostname to its IP addresses (IPv4 and IPv6).
+    /// IPv6 link-local addresses will include the zone index if applicable.
     /// </summary>
-    /// <returns><placeholder>A <see cref="Task"/> representing the asynchronous operation.</placeholder></returns>
     Task<IEnumerable<string>> ResolveHostnameAsync(string hostname, CancellationToken cancellationToken = default);
 
     /// <summary>
-    /// Expands configuration targets into concrete endpoints based on their host specification.
-    /// Handles single hosts, CIDR ranges, and wildcards.
+    /// Expands configuration targets into concrete endpoints based on host specification.
+    /// Supports single hosts, CIDR ranges, and wildcards.
+    /// Automatically handles IPv4 and IPv6 addresses, expanding IPv6 into compressed and full forms if needed.
     /// </summary>
-    /// <returns><placeholder>A <see cref="Task"/> representing the asynchronous operation.</placeholder></returns>
     Task<IEnumerable<Data.Endpoint>> ExpandTargetsAsync(IEnumerable<dynamic> configTargets,
         CancellationToken cancellationToken = default);
 }