Subnet / CIDR Calculator
Subnet details, binary views, CIDR-to-range tables, same-subnet checks — instant, in your browser.
Free Network Engineering Tools
Every tool below runs entirely in your browser — no signup, no install.
Bandwidth-Delay Product Calculator
Sizing TCP windows, Mathis throughput bounds under loss, packet rates, and file-transfer times — for the link you actually have.
Subnet Quiz
Endless CCNA-style practice: network addresses, broadcasts, host counts, and VLAN-range questions with explanations.
Availability / SLA Calculator
What an SLA percentage actually allows in downtime — and what your components add up to when reliability multiplies.
Data-Center Capacity Planner
Size a spine-leaf fabric: servers per leaf, uplinks per spine-leaf pair, oversubscription, and real bisection estimates.
Tick-to-Trade Latency Calculator
Build the path from market tick to order and see the waterfall — propagation, serialization, switch hops, and feed handling.
Optical Link Budget Calculator
Will this fiber run survive the physics? Power budget, per-element losses, link margin, and max reach — with realistic fiber presets.
PTP Timing Budget Calculator
Add up IEEE 1588 time error across a boundary-clock chain — worst-case and RMS totals checked against 5G, MiFID II, and power-utility budgets.
ECMP Hash Polarization Visualizer
Simulate ECMP hashing across a Clos fabric — watch identical hash seeds collapse traffic onto diagonal paths, and per-switch seeds spread it evenly again.
Firewall ACL Rule Analyzer
Paste a Cisco IOS extended ACL and find the dead rules — shadowed lines that can never fire, redundant duplicates, and dangerous permit ip any any holes.
Network config verifier
Paste Cisco IOS configs — one pane per device — and verify duplicate IPs, OSPF and BGP mismatches, subnet reachability and dead ACL rules. v1 Cisco IOS only.
PTP/SyncE Network-Wide Timing Simulator
Simulate a full PTP/SyncE chain over time — PI servo wander, per-hop asymmetry bias, PDV noise, holdover drift, and ITU-T G.8273.2 Class A–D pass/fail for every clock.
Wireshark Display Filter Builder
Build valid Wireshark display filters without memorizing syntax — field picker, AND/OR/NOT grouping, a gotcha linter, plain-English readout, and shareable filter links.
Wi-Fi Channel Interference Planner
Enter the APs you can hear — band, channel, width, RSSI — and get a spectral overlap graph, ranked channel recommendations for 2.4, 5, and 6 GHz, plus a printable multi-AP channel plan.
QoS Token-Bucket Policer & Shaper Simulator
Set CIR, Bc and Be the way you would on a Cisco MQC policy, inject traffic, and watch conform/exceed/violate coloring and shaping delay — with the exact IOS CLI.