Reachability and latency over TCP
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DNS Lookup Every DNS record for any domain A Record Lookup IPv4 addresses for a domain AAAA Record Lookup IPv6 addresses for a domain MX Lookup Mail servers for a domain NS Lookup Authoritative name servers TXT Lookup TXT records, SPF, verification CNAME Lookup Canonical name (alias) records SOA Lookup Start of Authority record SRV Lookup Service location records CAA Lookup Which CAs may issue certificates Reverse DNS (PTR) IP address to hostname DNSSEC Check Is the domain signed and validated? DNS Health Check A full delegation & DNS report cardEmail Deliverability
SPF Check Validate your Sender Policy Framework record DMARC Check Inspect and grade your DMARC policy DKIM Check Find and validate your DKIM public key Blacklist Check Check an IP against email blocklists (DNSBLs) SMTP Test Connect to a mail server and check STARTTLS MTA-STS Check Enforced TLS policy for inbound mail BIMI Check Brand logo record for email TLS-RPT Check SMTP TLS reporting policyNetwork & Web
SSL Certificate Check Inspect a site's TLS certificate and expiry HTTP Header Check Inspect response headers, redirects and security Ping (TCP) Reachability and latency over TCP Port Check Which common ports are openDomain
WHOIS Lookup Registration data for domains, IPs and ASNsA TCP ping measures whether a host is reachable and how fast it responds by opening a TCP connection rather than sending an ICMP echo. Because ICMP is unavailable behind most hosting and CDNs, IPeek measures reachability and latency with a TCP connection to ports 443 and 80, reporting the minimum, average and maximum round-trip time over several attempts.
The classic ping command sends an ICMP echo request and times the reply. That works on a local network but fails across much of the public internet, because firewalls, CDNs and cloud providers routinely drop or deprioritize ICMP. A TCP ping instead opens a real connection to a service port and times how long the handshake takes. Since web servers must accept connections on 443 and 80 to function, this reliably reaches hosts that never answer ICMP, and it measures the latency of the path that actually carries your traffic.
IPeek reports minimum, average and maximum round-trip time across several attempts. The minimum is the best-case latency of the path; the average is what you can typically expect. The gap between minimum and maximum is jitter: a small gap means a stable connection, while a large spread signals congestion or an overloaded host. As a rough guide, under 50 ms is excellent, 50 to 150 ms is normal across regions, and consistently high or wildly varying times point to a network or server problem worth investigating.
Reach for a TCP ping when a plain ping reports 100% packet loss but the site clearly loads, which simply means ICMP is filtered. Use it to confirm a server is accepting connections on its web ports, to compare latency to a host from your location, or to spot intermittent slowness before it becomes an outage. It is also the honest measurement when you care about real user experience, because it times the same TCP path that browsers and APIs use, not a separate ICMP channel.
Operators block or rate-limit ICMP to reduce attack surface and noise: ICMP floods were a classic denial-of-service vector, and echo replies leak information useful for reconnaissance. CDNs and load balancers also terminate connections at the edge, so an ICMP ping would measure the nearest edge node rather than the origin. Because of this, a failed ICMP ping says nothing about whether a site is up. A TCP ping to the ports the service actually listens on gives a reliable yes-or-no on reachability.
Regular ping uses ICMP, which firewalls and CDNs frequently drop, so it can report failure even when a site is fully online. TCP ping opens a connection to a service port like 443 or 80, which any working web server must accept. Because it uses the same path real traffic takes, it succeeds where ICMP is filtered.
Under 50 ms is excellent and feels instant, 50 to 150 ms is normal for connections that cross regions or continents, and above 150 ms becomes noticeable in interactive use. More important than the absolute number is consistency: a stable average with little spread between minimum and maximum means a healthy path, while large swings indicate congestion or an overloaded server.
They summarize several timed attempts. Minimum is the fastest response, representing the best-case latency of the network path. Average is the typical latency you can expect. Maximum is the slowest attempt. The spread between minimum and maximum is jitter; a tight spread means a stable connection, while a wide one points to congestion or instability on the route.
Yes, that is exactly what a TCP ping is for. Instead of an ICMP echo, it opens a TCP connection to ports 443 and 80, which web servers must accept to serve traffic. This reaches hosts behind firewalls and CDNs that silently drop ICMP, giving you a real reachability and latency reading where a standard ping would just time out.
Those are the standard HTTPS and HTTP ports that web servers must keep open to function, which makes them reliable targets for a connection-based ping. By timing the TCP handshake to these ports, IPeek measures the latency of the path that actually carries web traffic, and it confirms reachability for hosts that never answer ICMP echo requests behind modern hosting and CDNs.