method X509Certificate.prototype.checkIP
Usage in Deno
```typescript import { X509Certificate } from "node:node__crypto.d.ts"; ```
X509Certificate.prototype.checkIP(ip: string): string | undefined
Checks whether the certificate matches the given IP address (IPv4 or IPv6).
Only [RFC 5280](https://www.rfc-editor.org/rfc/rfc5280.txt) `iPAddress` subject alternative names are considered, and they
must match the given `ip` address exactly. Other subject alternative names as
well as the subject field of the certificate are ignored.
string | undefined
Returns `ip` if the certificate matches, `undefined` if it does not.