The Scenario
The network audit kicks off next week. Your manager forwarded you the routing table export at the end of last Friday — 1,000 IP addresses in a Google Sheet, one per row. Before the audit team shows up, you need the reverse-DNS hostname for each IP so you can identify device types, service names, and anything that looks out of place.
You got this task because you know networks. Not because you know Python.
The bad version:
- Open a terminal, run nslookup or dig for the first IP, copy the hostname.
- Paste it into the sheet. Row 1 done. 999 to go.
- Realize you can script this: write a shell loop or a Python script, run it, realize the output isn't tab-delimited in the way the sheet expects.
- Spend an hour on formatting, paste the results, discover 87 rows came back as empty strings instead of "No PTR record."
What should have been a preparatory task before the real work starts has become the work itself.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent inside your Google Sheet. Through its IPinfo integration, it can resolve the reverse-DNS hostname for every IP in your list and flag the ones with no PTR record — all in one prompt.
Open the SheetXAI sidebar and enter:
For each IP address in column A, use IPinfo to look up the reverse-DNS hostname and write it to column B. Flag rows where the hostname is empty as "No PTR record" in column C.
What You Get
- Column B: resolved hostname for each IP (e.g., "mail.acme.com" or "db-prod-02.internal.example.net")
- Column C: "No PTR record" for any IP that returned an empty hostname from IPinfo, blank otherwise
- All 1,000 rows resolved in one pass — no terminal, no script formatting, no re-import
What If the Data Is Not Quite Ready
IPs are mixed with subnet notation and I need to strip the prefix
Column A contains IP addresses in CIDR notation (e.g., 203.0.113.5/24). Strip the subnet prefix from each cell so only the host IP remains, look up the reverse-DNS hostname for each using IPinfo, and write the hostname to column B. Flag empty hostnames as "No PTR record" in column C.
I want to classify devices by hostname pattern
Look up the reverse-DNS hostname for all IPs in column A using IPinfo and write to column B. In column C, classify each hostname: write "Mail server" if the hostname contains "mail" or "smtp," "Database" if it contains "db" or "mysql" or "pg," "Web server" if it contains "web" or "www" or "nginx," and "Unknown" for everything else. Leave blank if no PTR record exists.
I only want to see rows with hostnames that contain our internal domain
Resolve reverse-DNS hostnames for all IPs in column A via IPinfo, write to column B. Filter to only rows where the hostname ends in ".acme.internal" or ".acme.net" and write those rows — IP and hostname — to a new tab called "Internal Devices."
Full audit prep: resolve, classify, flag anomalies, and summarize
Column A has 1,000 IPs from the routing table. Resolve reverse-DNS hostnames via IPinfo, write to column B. Classify each by device type based on hostname keywords (mail, db, web, vpn, fw for firewall) and write the classification to column C. Flag any IP where the hostname is empty as "No PTR" in column D. Flag any IP where the classification is "Unknown" but the hostname is not empty as "Review" in column D. Write a count-per-classification summary to a new tab called "Audit Prep Summary."
Audit prep done before the audit team walks in.
Try It
Get the 7-day free trial of SheetXAI and open any Google Sheet with a network inventory or routing table export, then ask it to resolve hostnames via IPinfo and classify your devices. See also abuse contact lookup for incident response or fast ASN enrichment for large logs. Hub: IPinfo + Google Sheets.