prefixkit RU

For network and telecom engineers

Network and telephony tools

IP addresses, DNS, BGP, SIP and phone numbers, for engineers, sysadmins and telecom teams. No sign-up; most checks run right in your browser.

  • 41 tools
  • 245 countries in the code directory
  • Rossvyaz numbering registry, refreshed monthly
  • Free and no sign-up
Your IP address detecting… Details and WebRTC leak test →

IP & network

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What is my IPYour address, city, provider, and a WebRTC leak test.IP lookupCountry, city, provider and reverse DNS of any IP.Is it down?Check a site from Russia, the UAE and worldwide.Speed testDownload, upload, jitter, bufferbloat, VoIP capacity.PingLatency and loss from probes around the world.Traceroute & MTRThe path packets take, from many countries.Port checkerIs a TCP port open from the internet.BGP & RPKI check newOrigin AS, ROA validity, visibility and AS paths.WireGuard config generator newServer and client configs, QR codes, MikroTik.MikroTik config generator newRouterOS 7 script: WAN, failover, VLANs, firewall, CAKE.MTU and MSS calculator newPPPoE, WireGuard, IPsec, GRE, VXLAN overhead and MSS.MAC vendor lookup newDevice maker by MAC, IEEE registry, many at once.Autonomous systemsEvery network of a provider, with firewall lists.

DNS, SSL & email

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DNS lookupAll records plus SPF, DKIM, DMARC and DNSSEC.DNS propagationIs a new record visible in 20 countries yet.WHOISRegistrar, dates and status of a domain or IP.SSL certificate check newExpiry, issuer, names, HTTPS redirect and HSTS.CSR generator newCSR and private key in the browser, RSA or ECDSA.SPF & DMARC generator newRecords for Google, Microsoft, Yandex and more.Blacklist checkAn IP or domain against 29 spam lists, plus PTR.HTTP security headers newHSTS, CSP, cookies, redirects and a grade.Email header analyzer newDelivery path, delays, SPF, DKIM, DMARC, spam.DMARC report analyzer newWho sends as your domain; when to set p=reject.

VoIP & telephony

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AI voice agent cost newRetell, ElevenLabs, Vapi, Bland vs human agents.AI agent ↔ PBX over SIP newAsterisk and FreeSWITCH configs for AI agents.VoIP pcap analyzerCalls, voice quality and why they dropped.SIP log analyzerLadder, SDP, NAT, DTMF and STIR/SHAKEN from a log.SIP server checkSRV, TCP/TLS and a SIP OPTIONS ping.SIP trunk generator newAsterisk pjsip.conf, FreeSWITCH gateway, Kamailio.MOS calculatorVoice quality from delay, jitter and loss.VoIP bandwidthBandwidth per call with all headers and VPN.Erlang B & CTrunk channels and call-centre agents needed.SIP response codesWhat every code means and what to check.Q.850 causesCall release causes and their SIP mapping.

Phone numbers

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Phone number lookupCountry, region, operator and number format.Country calling codes245 countries, area codes and operators.Russian mobile codesOperator and region of every 9xx code.

Subnets

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IPv4 subnet calculatorNetwork, mask, host range and splitting.IPv6 calculatorNotation, range, /64 count, reverse zone.CIDR aggregator newMerge subnets, ranges to CIDR, firewall lists.CIDR tableEvery prefix: mask, wildcard, hosts.

Calling codes on the map

Hover a country to see its code; select it for area codes and operators.