# Timing & Performance

#### 1. **--min-hostgroup ; --max-hostgroup**

Adjusts parallel scan group sizes.\
**Example**:\
Scan with a minimum group size of 50 hosts and a maximum group size of 200.

```bash
nmap --min-hostgroup 50 --max-hostgroup 200 192.168.1.0/24
```

#### 2. **--min-parallelism ; --max-parallelism**

Adjusts probe parallelization.\
**Example**:\
Set minimum parallelism to 10 and maximum parallelism to 50.

```bash
nmap --min-parallelism 10 --max-parallelism 50 192.168.1.1
```

#### 3. **--min-rtt-timeout , --max-rtt-timeout , --initial-rtt-timeout**

Adjusts probe timeouts.\
**Example**:\
Set the initial RTT timeout to 500ms, minimum to 100ms, and maximum to 1 second.

```bash
nmap --initial-rtt-timeout 500ms --min-rtt-timeout 100ms --max-rtt-timeout 1s 192.168.1.1
```

#### 4. **--max-retries**

Specifies the maximum number of port scan probe retransmissions.\
**Example**:\
Limit retries to 3 for each port scan probe.

```bash
nmap --max-retries 3 192.168.1.1
```

#### 5. **--host-timeout**

Specifies how long to wait for a host to respond before timing out.\
**Example**:\
Timeout hosts after 1 minute of no response.

```bash
nmap --host-timeout 1m 192.168.1.1
```

#### 6. **--script-timeout**

Sets the maximum allowed execution time for scripts.\
**Example**:\
Set the script timeout to 30 seconds.

```bash
nmap --script-timeout 30s 192.168.1.1
```

#### 7. **--scan-delay ; --max-scan-delay**

Adjusts delay between probes to avoid rate limiting.\
**Example**:\
Add a 1-second delay between each probe, with a maximum delay of 3 seconds.

```bash
nmap --scan-delay 1s --max-scan-delay 3s 192.168.1.1
```

#### 8. **--min-rate ; --max-rate**

Directly controls the scanning rate.\
**Example**:\
Set the minimum scanning rate to 500 packets per second, and a maximum rate of 1000 packets per second.

```bash
nmap --min-rate 500 --max-rate 1000 192.168.1.0/24
```

#### 9. **--defeat-rst-ratelimit**

Avoids rate limits for RST packets, speeding up SYN scans.\
**Example**:\
Use this option to bypass rate limiting for RST packets.

```bash
nmap --defeat-rst-ratelimit 192.168.1.1
```

#### 10. **-T**

Sets the scan timing template.\
**Example**:\
Use the "aggressive" timing template for faster scans.

```bash
nmap -T4 192.168.1.0/24
```

