TechnitiumSoftware/DnsServer · error · ArgumentOutOfRangeException

Valid range is from 1000 to 90000.

Error message

Valid range is from 1000 to 90000.

What it means

Thrown by the TcpSendTimeout property setter when the value is below 1000ms or above 90000ms. This controls the TCP send timeout for DNS responses over TCP, ranging from 1 second to 90 seconds.

Source

Thrown at DnsServerCore/Dns/DnsServer.cs:7518

        public int ClientTimeout
        {
            get { return _clientTimeout; }
            set
            {
                if ((value < 1000) || (value > 10000))
                    throw new ArgumentOutOfRangeException(nameof(ClientTimeout), "Valid range is from 1000 to 10000.");

                _clientTimeout = value;
            }
        }

        public int TcpSendTimeout
        {
            get { return _tcpSendTimeout; }
            set
            {
                if ((value < 1000) || (value > 90000))
                    throw new ArgumentOutOfRangeException(nameof(TcpSendTimeout), "Valid range is from 1000 to 90000.");

                _tcpSendTimeout = value;
            }
        }

        public int TcpReceiveTimeout
        {
            get { return _tcpReceiveTimeout; }
            set
            {
                if ((value < 1000) || (value > 90000))
                    throw new ArgumentOutOfRangeException(nameof(TcpReceiveTimeout), "Valid range is from 1000 to 90000.");

                _tcpReceiveTimeout = value;
            }
        }

        public int QuicIdleTimeout

View on GitHub (pinned to d0484b6c1e)

Solutions

1. Set a value between 1000 and 90000 milliseconds (e.g. 15000 for 15 seconds).
2. Convert seconds-based config values to milliseconds.

Example fix

// before
server.TcpSendTimeout = 500; // throws, below floor

// after
server.TcpSendTimeout = 15000;

int safeTimeout = Math.Clamp(value, 1000, 90000);
server.TcpSendTimeout = safeTimeout;

static bool IsValidTcpTimeout(int ms) => ms >= 1000 && ms <= 90000;

try { server.TcpSendTimeout = value; }
catch (ArgumentOutOfRangeException) { server.TcpSendTimeout = 15000; }

When it happens

Trigger: Setting server.TcpSendTimeout to an int < 1000 or > 90000.

Common situations: Passing seconds instead of milliseconds; setting an aggressive sub-second timeout; config file with a value outside the allowed band.

Related errors

• Valid range is from 1000 to 10000.
• Cannot update DNS zone '{zoneInfo.DisplayName}': not a prima
• Cannot update reverse DNS zone '{reverseZoneInfo.DisplayName
• Port 853 is reserved for DNS-over-TLS service. Please use a
• Networks cannot have more than 255 entries.

AI-assisted analysis of TechnitiumSoftware/DnsServer@d0484b6c1e (2026-08-13). Data as JSON: /api/errors/4607ea789b98844b. Report an issue: GitHub.