Network Tools: IP, DNS, Subnet, WHOIS, Ports and Traceroute
These are the tabs I leave open when a network starts misbehaving. IPs and DNS, sure. Reverse DNS, subnet math, geolocation, port checks, the whole WHOIS trail too. Honestly, half of them I reach for out of habit more than need. No installs, no accounts. You open one and it works.
MAC Address LookupPaste any MAC and get the OUI vendor, plus the I/G and U/L bits spelled out. It flags VMware, Hyper-V and VirtualBox prefixes when it spots them.What Is My IPYour public IP at a glance. Plus the stuff your browser leaks without telling you.Domain Health CheckOne sweep covers DNS, WHOIS, SSL, mail and headers. I run it before every launch.IP Geolocation LookupTells you the country, city, ASN and ISP. Good enough to flag a weird login, but it’s not GPS, so don’t treat it like it is.Subnet CalculatorCIDR, netmask, broadcast, VLSM. The mental math I flat out refuse to do by hand anymore.DNS LookupA, AAAA, MX, TXT, NS, CNAME, SOA, CAA. First thing I poke at when mail suddenly stops landing.Reverse DNS LookupPaste a whole pile of IPs. Get every PTR record back in one go.WHOIS LookupWho owns it. When it expires, plus the nameservers and the DNSSEC bits.Ping TestHammer a host on repeat, watch the latency move. Is it down, or is it just me?Traceroute VisualizerDump your traceroute output here and see exactly which hop falls over.Port CheckerIs that TCP port actually open? Quick yes or no, with a hint at whatever’s sitting behind it.Public IP vs Local IPPrivate ranges and NAT, and what’s actually routable. Most people get this wrong at least once.IPv4 / IPv6 ConverterIPv4-mapped IPv6, integer, hex. For when a log hands you the one format you didn’t want.
Network diagnostics in one place
I built this corner around what I actually use day to day. IPs, DNS records, subnets, ports, the odd ownership trail. Grab them when you’re planning out a network or chasing down why a domain’s gone weird. Or just to jot down what changed on a box before you forget (you will forget). Everything runs in your browser. I don’t see it, and nothing gets stored. Maybe that’s overkill for a subnet calc, but I’d rather it stay that way.
