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did you ping it?

Small networking tasks, solved instantly. 85 tools for subnets, DNS, packets, Cisco, testing, conversion, and learning.

IPv4 Subnet CalculatorCIDR CalculatorVLSM CalculatorSubnet SplitterSubnet Range Calculator

Having a problem?

Walk DNS → ping → TCP → HTTP → TLS step by step.

Troubleshoot a network problem
I know what tool I need → search or browse belowI know what's broken → troubleshoot

Subnetting

12 tools

Carve networks, decode CIDR, plan VLSM.

IPv4 Subnet Calculator

Network, broadcast, range from IP + prefix

CIDR Calculator

Decode 10.0.0.5/16 style input

VLSM Calculator

Allocate subnets by host count

Subnet Splitter

Split network into equal subnets

Subnet Range Calculator

First to last usable IP

Usable Host Calculator

Hosts per prefix length

Subnet Mask Calculator

Mask for host count

Wildcard Mask Calculator

Inverse mask for ACLs

CIDR to Subnet Mask

/24 to 255.255.255.0

Subnet Mask to CIDR

255.255.255.0 to /24

Network Address Calculator

IP AND mask

Broadcast Address Calculator

Last address of subnet

IP Addressing

14 tools

Validate, convert, classify, and range IPv4 and IPv6.

IPv4 Address Validator

Valid or not, with reason

IPv4 to Binary

Dotted decimal to binary

Binary to IPv4

Binary back to dotted decimal

IP Range Calculator

Count addresses between two IPs

IP Range Generator

List every IP in range

Private IP Checker

Private, CGNAT, public, scope

IPv6 Subnet Calculator

Network + last address + total

IPv6 Address Validator

Valid or not, expanded form

IPv6 Compression & Expansion

Shortest vs full form, RFC 5952

MAC Address Formatter

All notations + unicast/OUI info

MAC Address Validator

Valid or not, with reason

IP Geolocation Lookup

City, ISP, coords + disclaimer

ASN Lookup

Origin AS + prefix via Cymru

BGP Prefix Lookup

Announcing prefix + origin AS

DNS

9 tools

Resolve records, reverse IPs, inspect mail and name servers.

DNS Lookup

A/AAAA/MX/CNAME/TXT/NS records

Reverse DNS Lookup

IP to hostname via PTR

MX Record Lookup

Mail servers + priority

A Record Lookup

Hostname to IPv4

CNAME Lookup

Alias chain target

TXT Record Lookup

SPF, DKIM, verification

NS Record Lookup

Authoritative nameservers

DNS Propagation Checker

A records across 4 resolvers

WHOIS Lookup

Registration + referral follow

Ports & Protocols

3 tools

Look up ports, services, and HTTP status codes.

Port Number Lookup

Service behind the port

HTTP Status Code Lookup

What 404 really means

ICMP Type/Code Lookup

Echo, unreachable, TTL expired

Network Testing

3 tools

Ping, trace, and inspect live HTTP responses.

Ping Tester

ICMP latency, TCP fallback

Traceroute

Hop-by-hop path trace

HTTP Header Checker

Status + response headers

Calculators

9 tools

Host counts, masks, and ranges at a glance.

IPv4 Subnet Calculator

Network, broadcast, range from IP + prefix

CIDR Calculator

Decode 10.0.0.5/16 style input

VLSM Calculator

Allocate subnets by host count

Usable Host Calculator

Hosts per prefix length

Subnet Mask Calculator

Mask for host count

IP Range Calculator

Count addresses between two IPs

Bandwidth Calculator

Users x rate + overhead

Transfer Time Calculator

File size / rate + overhead

Latency Calculator

Propagation + transmission

Packet Analysis

4 tools

Decode headers byte by byte.

IPv4 Header Decoder

Every field from hex

TCP Header Decoder

Ports, seq, flags, window

UDP Header Decoder

Ports, length, checksum

Ethernet Frame Decoder

MACs + EtherType + payload

Converters

8 tools

Hex, decimal, and binary both ways, any size.

URL Parser

Split URL into parts

URL Encoder/Decoder

Percent-encoding both ways

Hex to Binary

FF to 11111111

Binary to Hex

11111111 to FF

Decimal to Binary

255 to 11111111

Binary to Decimal

11111111 to 255

Hex to Decimal

FF to 255

Decimal to Hex

255 to FF

Cisco

10 tools

Student and engineer toolkit: IOS commands, ACLs, VLANs, OSPF, EIGRP, STP.

Cisco Wildcard Mask Calculator

Wildcard + network statement

Cisco ACL Generator

Extended ACL lines + deny note

Cisco VLAN Calculator

ID class + vlan snippet

Cisco Subnet Calculator

Mask + IOS commands

Cisco Port Range Generator

interface range command

Cisco IP Calculator

Class + default mask

Cisco Config Generator

Hostname + interfaces + route

OSPF Cost Calculator

10^8 / bandwidth, min 1

EIGRP Metric Calculator

Classic composite + K note

STP Root Bridge Calculator

Priority + VLAN + MAC vote

Learning

15 tools

Drills that grade you plus reference sheets worth bookmarking.

Subnetting Practice Generator

Random drills, graded live

IP Address Quiz

Classify scope, graded live

CIDR Practice

Prefix-mask drills

VLSM Practice

Smallest-fit drills

Wildcard Mask Practice

Inverse-mask drills

Port Number Quiz

Service-port drills

OSI Model Reference

7 layers, PDU, examples

TCP/IP Model Reference

4 layers + OSI mapping

TCP Flags Reference

9 flags, when seen

DNS Record Types Reference

A to CAA cheat sheet

IPv4 Address Classes Reference

A-E + private ranges

IPv6 Prefix Reference

Special prefixes cheat sheet

HTTP Status Codes Reference

All codes grouped

Well-Known Ports Reference

Full common-ports table

Network Protocol Reference

Protocols, ports, purpose

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