diff --git a/checks.go b/checks.go
index 3295d02..4b21e76 100644
--- a/checks.go
+++ b/checks.go
@@ -189,7 +189,7 @@ func executeDNSCheck(ctx context.Context, config *pb.DnsCheckConfig, timeoutMs u
 			PreferGo: true,
 			Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
 				d := net.Dialer{Timeout: timeout}
-				return d.DialContext(ctx, "udp", config.Server+":53")
+				return d.DialContext(ctx, "udp", net.JoinHostPort(config.Server, "53"))
 			},
 		}
 	}
diff --git a/lldp.go b/lldp.go
index 66095dc..8766ffa 100644
--- a/lldp.go
+++ b/lldp.go
@@ -36,7 +36,7 @@ func executeLldpTopologyJob(ctx context.Context, job *pb.AgentJob, resultCh chan
 	snmpDev := job.SnmpDevice
 	client, err := newSnmpConn(snmpDev)
 	if err != nil {
-		slog.Error("failed to create SNMP client for LLDP", "job_id", jobID, "device_id", deviceID, "error", err)
+		slog.Error("failed to connect SNMP for LLDP", "job_id", jobID, "device_id", deviceID, "error", err)
 		return
 	}
 	defer func() {
@@ -45,11 +45,6 @@ func executeLldpTopologyJob(ctx context.Context, job *pb.AgentJob, resultCh chan
 		}
 	}()
 
-	if err := client.Connect(); err != nil {
-		slog.Error("SNMP connect failed for LLDP", "job_id", jobID, "device_id", deviceID, "error", err)
-		return
-	}
-
 	result, err := discoverLldpNeighbors(client, deviceID, jobID)
 	if err != nil {
 		slog.Error("LLDP discovery failed", "job_id", jobID, "device_id", deviceID, "error", err)