The network and DNS tools in Admin Tools

What are the network and DNS tools?

Admin Tools by Cloud Captains is a Chrome extension with more than 130 standalone tools, organised into 11 categories. One of those is the Network category. It contains seven tools that help you understand connections, domain names and devices on a network: the subnet calculator, DNS lookup, MAC address lookup, WHOIS, network speed test, ping and ASN lookup.

You open each of these tools from the extension popup. Click the Admin Tools icon in your toolbar, choose the Network category and select the tool you need. You can learn more about the whole extension on the homepage: https://cloud-captains.com/admin-tools/.

Why are these tools useful?

As a developer, IT administrator or power user you run into questions every day such as: which subnet does this IP address belong to, which IP does this domain point to, which manufacturer made this device, who owns this domain, and how fast is my connection really right now. In the past you had to track down separate websites or command line tools for each of these. Admin Tools brings them together in one place, right next to your browser.

An important point: many of these tools work entirely locally in your browser. The subnet calculator, for example, computes everything on your own device, without sending anything to the internet. Tools that do need external data (such as a DNS server or a WHOIS database) call only that one specific service, and only when you actively use the tool. There is no telemetry and nothing goes to a general server.

The subnet calculator

The subnet calculator helps you split or understand an IP range. You enter an IP address and a subnet mask (for example 192.168.1.0/24) and the tool shows you the network address, the broadcast address, the usable range of addresses, the number of hosts and the matching mask in several notations.

This is especially handy when you are planning a network, writing firewall rules, or checking whether two devices sit in the same subnet.

DNS lookup

With the DNS lookup you find out what a domain name points to. You can request several types of records: A and AAAA (the IP address), MX (mail servers), TXT (free text, often used for verification and SPF), NS (name servers), CNAME (aliases) and more.

This is useful when you want to check whether a domain is set up correctly, whether a change has propagated, or why email is not being delivered.

The DNS lookup uses Google's public DNS service (dns.google) to retrieve the records. This means the domain name you look up is sent to that service, because a lookup cannot work without querying a DNS server.

MAC address lookup

Every network device has a unique MAC address. The first half of it, known as the OUI part, identifies the manufacturer. With the MAC address lookup you enter a MAC address and see which manufacturer built the device.

This helps you, for example, to recognise an unknown device on your network, or to verify that a device comes from the expected vendor.

The MAC lookup queries the macvendors.com service to match the manufacturer to the address. Only the MAC address you enter is sent there.

WHOIS

With WHOIS you look up who registered a domain name and when. You see, among other things, the registrar, the registration and expiry dates, and the name servers. For many domains, personal details are now hidden because of privacy legislation, but the organisational data often remains visible.

This is useful when you want to know whether a domain is about to expire, who to contact about a domain, or when a domain was last transferred.

The WHOIS tool uses the port.cloud-captains.com proxy to request the WHOIS data. The domain name you enter is sent to that proxy.

Network speed test

The network speed test measures how fast your internet connection is at this moment. The test uses several mirrors spread across different providers, so the measurement is representative and does not depend on a single server. The mirrors used include bit.nl, i3d, ovh, vultr and cloudflare.

This is handy when you want to check a slow connection, test a new internet line, or compare whether a vpn affects your speed.

Ping

With the ping tool you check whether a host is reachable and how long a request takes to travel there and back. It gives you an impression of the response time, also known as latency.

This is useful when you want to know whether a server is online, or when you are trying to diagnose a slow or unstable connection.

The ping tool works through the port.cloud-captains.com proxy, because a browser cannot send a raw ping by itself. The address you test is sent to that proxy.

ASN lookup

An ASN (Autonomous System Number) is a unique number that belongs to a network operator, for example an internet provider or a large company. With the ASN lookup you find out which organisation sits behind an IP address or network, and which IP ranges belong to that organisation.

This helps you understand who runs the network that traffic comes from, for example when investigating log files or identifying a provider.

The ASN lookup also uses the port.cloud-captains.com proxy, which can additionally return GeoIP data about the location of the network.

Which tool do you use when?

In short:

• To plan an IP range or check whether two addresses are in the same network, use the subnet calculator (local).
• To find out which IP or mail server a domain points to, use the DNS lookup.
• To find the manufacturer of a device, use the MAC address lookup.
• To find out who registered a domain, use WHOIS.
• To measure your connection speed, use the speed test.
• To check whether a host is reachable, use ping.
• To find out which operator runs a network, use the ASN lookup.