Network & SysAdmin
IPv4 CIDR subnet calculators, network diagnostics, and system administrator utilities.
Available Tools (45)
← Back to all toolsIP & Subnet Calculation
IPv4 Subnet Calculator
Calculate IPv4 network, mask, broadcast, host range and address counts for prefixes /0 through /32, including /31 point-to-point links.
IPv6 Subnet & Prefix Calculator
IPv6 Subnet & Prefix Calculator: Computes available subnet bits (64 - 48 = 16 bits), calculating total possible subnets (2^16 = 65,536).
IPv4 ↔ IPv6 Converter
IPv4 ↔ IPv6 Converter: Converts dotted-decimal octets into hexadecimal notation and constructs RFC 4291 compliant addresses.
IP Range to CIDR Calculator
IP Range to CIDR Calculator: Computes continuous binary powers of two to generate the minimal set of enclosing CIDR blocks.
CIDR to IP Range & Host List
CIDR to IP Range & Host List: Enumerates all 8 addresses within the /29 subnet, excluding network (10.0.0.0) and broadcast (10.0.0.7).
Private IP & Bogon Address Checker
Private IP & Bogon Address Checker: Checks IP against RFC 1918 private, RFC 5735 loopback, and IANA full bogon prefix tables.
Subnet Mask to Wildcard Mask (Cisco)
CIDR Prefix to Wildcard Mask Calculator: validates an IPv4 address and optional /0–/32 prefix, then returns the contiguous subnet mask and its 32-bit complement; it is not a bidirectional mask or ACL generator.
Route Summarization / CIDR Aggregation
Route Summarization / CIDR Aggregation: Compares binary bit patterns across all 4 subnets, finding 22 common network prefix bits.
IPv6 Subnet & Prefix Allocation Planner
IPv6 Subnet & Prefix Allocation Planner: Borrows 2 bits (56 + 2 = /58), creating 4 non-overlapping /58 subnet blocks.
IP Address Binary, Hex & Integer Converter
IP Address Binary, Hex & Integer Converter: Shifts octets: (192 << 24) + (168 << 16) + (1 << 8) + 1 to compute 32-bit unsigned integer.
Tool category
DNS WireFormat Hex Packet Parser
DNS WireFormat Hex Packet Parser: Parses RFC 1035 header: Transaction ID 0xaaaa, Flags standard query, Questions: 1 (example.com, Type: A, Class: IN).
Offline HAR Network Waterfall Analyzer
Offline HAR Network Waterfall Analyzer: Calculates request timing breakdown: DNS lookup, Initial connection, SSL handshake, Waiting (TTFB), and Content Download.
DNS Propagation Delay Estimator
DNS Propagation Delay Estimator: Calculates recursive resolver cache decay timelines based on RFC 1035 TTL countdown rules.
MAC Address OUI Vendor Lookup
MAC Address OUI Vendor Lookup: Normalizes a MAC address and compares its first 24 bits with five bundled OUI sample prefixes; it does not query the IEEE registry.
Network MTU & MSS Overhead Calculator
Network MTU & MSS Calculator: for any finite non-negative input MTU, returns max(0, MTU − 40) for IPv4 MSS and max(0, MTU − 60) for IPv6 MSS; it does not model tunnel overhead.
WebRTC SDP Session Description Protocol Parser
WebRTC SDP Session Description Protocol Parser: Parses RFC 4566 SDP line tokens: version, origin, media types (audio), ports, and codec payload mappings (PCMU/8000).
Wireshark Display Filter Syntax Helper
Wireshark Display Filter Syntax Helper: Formats valid Wireshark / tshark display filter syntax using boolean operators.
DNS Amplification Factor Calculator
DNS Amplification Factor Calculator: Computes Amplification Factor = Response Size / Request Size = 3200 / 64.
Ethernet Frame & 802.1Q VLAN Inspector
Ethernet Frame & 802.1Q VLAN Inspector: Parses Destination MAC (00:1A:2B:3C:4D:5E), Source MAC, TPID 0x8100 (802.1Q VLAN Tag), VID (100), and EtherType 0x0800 (IPv4).
TCP Handshake & State Machine Visualizer
TCP Handshake & State Machine Visualizer: Models a documented educational subset of RFC 9293 state transitions for open, close, ACK, FIN, RST, and timeout events. It is not packet capture or a complete TCP implementation.
Network Ping Latency & ICMP Guide
Network Ping Latency & ICMP Guide: Categorizes latency against standard networking benchmarks (gaming, VoIP, video streaming).
Traceroute Path Hop Analyzer
Traceroute Path Hop Analyzer: Parses IP hops, computes delta latencies, and flags major latency jumps (> 50ms).
Tool category
Well-Known Port Directory (1-65535)
Well-Known Port Directory (1-65535): looks up a bundled common-service subset and tells you to consult IANA for entries outside it.
URL Parser & Query Param Visualizer
URL Parser & Query Param Visualizer: Parses URL components conforming to the WHATWG URL Standard.
cURL Command Builder & Flag Explainer
cURL Command Builder & Flag Explainer: Formats valid POSIX cURL command line and generates an itemized flag explanation dictionary.
HTTP Methods Idempotency & Safety Guide
HTTP Methods Idempotency & Safety Guide: Cross-references RFC 9110 HTTP Semantics specifications for safety and idempotence properties.
Open Graph & Twitter Card Generator
Open Graph & Twitter Card Generator: Generates valid W3C HTML5 Open Graph protocol (og:) and Twitter Card (twitter:) metadata tags.
Browser Capabilities & WebGL Inspector
Browser Capabilities & WebGL Inspector: Inspects navigator object, WebAssembly SIMD, WebGL 2.0 context, Web Workers, and StorageManager quotas.
Data Transfer Speed & Time Calculator
Data Transfer Speed & Time Calculator: Converts bits to bytes (100 Mbps = 12.5 MB/s) and divides file size: 10,240 / 12.5 = 819.2 seconds.
BGP Autonomous System Number (ASN) Guide
BGP Autonomous System Number (ASN) Guide: shows fixed RFC private-use, documentation, and reserved ranges; it does not query BGP, RIR, or IANA.
IANA Top-Level Domains (TLD) Directory
IANA Top-Level Domains (TLD) Directory: shows bundled examples and an authoritative registry link; it does not contain or query the changing root-zone database.
WHOIS Domain Registration Guide & Portal
WHOIS Domain Registration Guide & Portal: Parses ICANN WHOIS record fields: Registrar, Creation Date, Expiration Date, Name Servers, and DNSSEC status.
SSL Certificate Chain Validator Guide
SSL Certificate Chain Validator Guide: Verifies that the server certificate Subject Key Identifier matches the intermediate's Authority Key Identifier.
Cache-Control Header Best Practice Builder
Cache-Control Header Best Practice Builder: Constructs RFC 9111 Cache-Control header directives for public CDN and browser caches.
HTTP/2 & HTTP/3 Protocol Explainer
HTTP/2 & HTTP/3 Protocol Explainer: Analyzes Head-of-Line (HoL) blocking behaviors: HTTP/2 TCP stalls all streams on single packet loss; HTTP/3 QUIC isolates streams over UDP.
WebSocket Heartbeat & Timeout Calculator
WebSocket Heartbeat & Timeout Calculator: Applies standard safety margin (ping at 50% of timeout threshold): 60 * 0.50 = 30 seconds.
Data Transfer & Bandwidth Unit Converter
Data Transfer & Bandwidth Unit Converter: Divides by 8 (1 Byte = 8 bits): 100 / 8 = 12.5 MB/s.
HTTP Redirects (301/302/307/308) Guide
HTTP Redirects (301/302/307/308) Guide: Evaluates RFC 9110 specifications: 301 permits clients to rewrite POST to GET; 308 strictly preserves POST method and body.
DNS CAA Record Generator
DNS CAA Record Generator: Constructs standard RFC 6844 DNS CAA resource records for issue, issuewild, and iodef tags.
Tool category
SSH Client Config (`~/.ssh/config`) Generator
SSH Client Config (`~/.ssh/config`) Generator: Formats OpenSSH client configuration directives adhering to ssh_config(5) specifications.
Systemd Service Unit File Generator
Systemd Service Unit File Generator: Constructs systemd unit sections [Unit], [Service], and [Install] with standard restart triggers.
Nginx & Apache Reverse Proxy Config Builder
Nginx & Apache Reverse Proxy Config Builder: Constructs standard Nginx server block with proxy_pass, proxy_set_header, and HTTP/1.1 upgrade directives.
Apache .htaccess to Nginx Rewrite Converter
Apache .htaccess to Nginx Rewrite Converter: Translates Apache mod_rewrite directives into Nginx PCRE `rewrite ... break;` or `rewrite ... last;` rules.
Syslog Message Format Validator (RFC 5424)
Syslog Message Format Validator (RFC 5424): Parses PRI (<34> = Facility auth, Severity crit), version (1), timestamp, hostname, app-name, and structured data.
SNMP Object Identifier (OID) Lookup
SNMP Object Identifier (OID) Lookup: Traverses standard IETF MIB-II tree: iso(1).org(3).dod(6).internet(1).mgmt(2).mib-2(1).system(1).sysUpTime(3).0.