TCP/IP Header Analyzer — ASN & BGP Route Lookup
ASN, organization, and BGP prefix data — not live TCP/IP header dissection
How to Use This Tool
- Enter a public IPv4 address or ASN (AS15169 or 15169) in the query field.
- ASN-shaped input normalizes AS prefix and queries BGPView ASN registry.
- For ASN queries, BGPView prefixes API returns up to twenty IPv4 prefixes.
- IP input maps address to originating ASN and org via geolocation lookup.
- prefixes and prefixCount populate for successful ASN prefix fetches.
- Read note field — IP-only queries return ASN metadata without full prefix tables.
About This Tool
The page title references TCP/IP headers, but VSPIC is transparent about actual behavior: tcp-ip-header-analyzer calls the bgp-route action, not packet capture. Enter an IPv4 address or ASN such as AS15169 — lookupAsn returns asn, name, org, country, prefix, and ip fields from BGPView registry data and geolocation; ASN-only input additionally fetches up to twenty ipv4_prefixes from BGPView with prefixCount when the prefixes API succeeds, otherwise registry metadata returns with note about route details from BGPView ASN lookup.
There is no live TCP header dissection, IP TTL analysis, TCP window size reading, or raw frame capture on this page. Use bgp-route-lookup for the same backend with routing-focused SEO, or dedicated packet tools elsewhere for true header analysis. This page exists to serve search demand while explaining limitations honestly.
Common use cases
- •Measure download and upload speed
- •Test open ports on a home router or server
- •Trace routing paths to diagnose latency
Why use VSPIC for ?
- Honest mapping from IP to ASN and organization ownership.
- ASN queries include sample IPv4 prefix announcements.
- prefixCount shows total prefixes even when display caps at twenty.
- Free BGPView-backed registry lookup without RIR portal logins.
- Same bgp-route action as bgp-route-lookup — consistent JSON.
- Useful for abuse attribution when headers are unavailable.
Honest disclosure about page title versus behavior
True TCP/IP header analysis requires packet capture — Wireshark, tcpdump, or mirrored SPAN ports reading Ethernet, IP, TCP, and UDP fields live. Our page does not capture packets and does not return TTL, DSCP, TCP flags, sequence numbers, or option lists.
Instead handleBgpRoute runs lookupAsn: IP input yields ASN and org from geolocation; ASN input queries BGPView for registry metadata and optional IPv4 prefix list. We state this clearly so operators are not misled during incident response.
What bgp-route returns for IP input
IPv4 query returns asn, name, org, country, ip, and prefix fields from geolocation and registry correlation. note may state route details from BGPView ASN lookup when prefix enumeration did not run — IP-only path does not fetch full prefix tables.
Use results for ownership attribution — which provider announces the address — not for transport-layer troubleshooting.
What bgp-route returns for ASN input
AS15169 style input triggers BGPView asn/{num}/prefixes fetch. Successful responses add prefixes array sliced to twenty entries and prefixCount for total IPv4 announcements. Failed API calls fall through to registry-only asnInfo with explanatory note.
Large providers announce hundreds of prefixes — twenty-sample display still confirms AS identity for abuse tickets.
When this lookup still helps investigators
Mail headers and HTTP logs often include IP without packet captures. Mapping IP to ASN and org feeds abuse-contact-finder and provider escalation even when TCP header analysis is impossible.
Students conflating TCP/IP headers with routing ownership still get useful ASN education — provided they understand this is BGP registry data, not frame dissection.
Relationship to bgp-route-lookup
tcp-ip-header-analyzer and bgp-route-lookup both call action bgp-route with identical JSON. bgp-route-lookup uses routing SEO vocabulary; this page serves TCP/IP header search demand with explicit limitation disclaimers.
Prefer bgp-route-lookup for peering research documentation; use this page when explaining honest behavior to stakeholders who arrived via header-analysis searches.
What to use for real header analysis
Capture packets on the observing host or network tap, then inspect in Wireshark. traceroute on our suite shows path hops — complementary to but distinct from header field parsing.
HTTP header analysis lives in security-headers-checker and cookie-analyzer — application-layer headers, not IP/TCP frames.
Security and hijack context
BGP lookup establishes baseline ASN ownership for an IP — useful before alleging route hijack. Continuous RPKI validation requires dedicated monitoring services beyond this on-demand lookup.
Incident responders paste attacker IPs to identify hosting ASNs for ticket templates — org field feeds abuse desk narratives.
API action bgp-route
GET /ip-tools/api/extended?action=bgp-route&query=8.8.8.8 or query=AS15169. Parse asn, org, prefixes, prefixCount, note. Branch automation on whether input was ASN-shaped.
Cache ASN metadata longer than prefix lists — registry data changes slower than routing dynamics.
Setting stakeholder expectations
If compliance asks for TCP header analysis evidence, clarify this tool provides ASN ownership only — not packet captures suitable for forensic chain of custody.
Our limitations section and intro state the mismatch explicitly to reduce tool misuse in court or audit contexts.
Important notes & limitations
- Does not analyze TCP/IP packet headers — title is SEO legacy, not capability.
- No TTL, window size, flags, or options field inspection.
- Prefix API may fail — falls back to registry-only with note.
- IPv6 prefix enumeration not emphasized in current API path.
- BGP snapshot is point-in-time — not continuous hijack monitoring.
Frequently Asked Questions
Yes. VSPIC offers this TCP/IP header analyzer at no cost with no account required. Results load in real time.
We do not permanently store your queries on our servers. Some tools run entirely in your browser; others fetch public data for the request only.
Yes. Open the page in any modern phone or tablet browser. Results work on Wi‑Fi and mobile data.
No. Despite the page title, it runs BGP/ASN lookup via bgp-route — returning ASN, org, and optional prefixes. Use Wireshark for real header analysis.
IPv4 for ASN ownership of that address. AS number (AS15169 or 15169) for registry metadata and up to twenty sample IPv4 prefixes.
IP-only queries return ASN metadata without prefix tables. ASN queries may fall back when BGPView prefixes API is unavailable — see note field.
Same bgp-route API and JSON. This page honestly discloses it does not perform TCP header analysis despite its title.
No. There is no packet capture. Only ASN, org, country, and optional BGP prefix data.
bgp-route with the query parameter.
Next step for your check
Continue with bgp route lookup on VSPIC.
Related Tools
Explore more free VSPIC tools for IP, DNS, security, and network diagnostics.
BGP Route Lookup
ASN information, route details, and network owner
Use Free →ASN Lookup
Find autonomous system number, name, and network prefix
Use Free →Traceroute Tool
Trace the network path packets take to a destination
Use Free →IP Lookup
Look up any IP address for ISP, location, and ASN details
Use Free →Speed Test
Measure download, upload, ping, and jitter for your connection
Use Free →Ping Test
Measure latency to any hostname or IP address
Use Free →
Trusted by Users Who Value Privacy
Always Free
No premium plan ever
100% Private
Files processed in browser
Instant Results
Convert in seconds
Works Everywhere
Any device, any OS