Network & IP Tools
Subnet maths, IP lookups, encoders and password generation — the sysadmin sidebar you keep open in a second tab.
Built for sysadmins, network engineers, security teams. 16 tools published.
CIDR Overlap Checker
10.0.0.0/8 and 10.1.0.0/16 look unrelated and one sits entirely inside the other. Paste a list and see which blocks collide, and which merely contain another.
🌐CIDR to IP List
A /24 is 256 addresses and 254 usable hosts. Get the explicit list, with the network and broadcast addresses labelled instead of quietly included.
🌐CIDR to Subnet Mask
Every prefix from /0 to /32 with its netmask, wildcard, host count and binary. Handles /31 and /32, which the usual formula gets wrong.
🌐DHCP Pool Planner
A lease is held until it expires, not until the device leaves. With an eight-day default and heavy churn, the pool fills with ghosts.
🌐DSCP Value Format
Translate a six-bit DSCP codepoint into packet-header representations.
🌐IP Range Checker
Private, loopback, link-local, carrier-grade NAT, multicast and reserved — with what each one means when you find it somewhere unexpected.
🌐IP Range to CIDR
192.168.1.5 to 192.168.1.10 is four CIDR blocks, not one. Firewalls want CIDR and people think in ranges, so here is the exact conversion.
🌐IPv6 Compressor
The same address has many valid spellings and exactly one canonical one. If your code compares addresses as strings, only the canonical form is safe.
🌐IPv6 Subnetting
A /48 gives 65,536 subnets and every one of them should be a /64. Subnetting smaller breaks the autoconfiguration that hosts rely on.
🌐MAC Address Format
Convert between colon, dash, Cisco and bare formats, and read the two bits that say whether an address is multicast or a randomised one no vendor ever owned.
🌐MTU Payload Efficiency
Subtract every modeled header from MTU before estimating payload efficiency and packet count.
🌐Packet Capture Storage
Apply sampling, captured-byte fraction and compression to a line-rate storage ceiling.
🌐Password Generator
Generated with your browser's cryptographic RNG, scored in bits of entropy rather than a vague coloured bar, with crack-time estimates for four attacker budgets.
🌐Route Summarization
192.168.1.0/24 and 192.168.2.0/24 summarize to 192.168.0.0/22 — which also claims two networks you never mentioned.
🌐Subnet Calculator
Network, broadcast, first and last usable address, mask, wildcard and host count — from any CIDR or dotted mask, with the binary boundary shown so it makes sense.
🌐VLSM Planner
A subnet must start on a multiple of its own size, so a large block placed after small ones can be blocked by a boundary while addresses remain.