doc: describe what tls servername is for

Docs should describe the purpose of the option. PR-URL: #24236 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Colin Ihrig <[email protected]>
nodejs · Dec 26, 2018 · 31441f4 · 31441f4
1 parent 0c206e0
commit 31441f4
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/doc/api/tls.md b/doc/api/tls.md
@@ -892,7 +892,10 @@ changes:
     first byte is the length of the next protocol name. Passing an array is
     usually much simpler, e.g. `['hello', 'world']`.
   * `servername`: {string} Server name for the SNI (Server Name Indication) TLS
-    extension. It must be a host name, and not an IP address.
+    extension. It is the name of the host being connected to, and must be a host
+    name, and not an IP address. It can be used by a multi-homed server to
+    choose the correct certificate to present to the client, see the
+    `SNICallback` option to [`tls.createServer()`][].
   * `checkServerIdentity(servername, cert)` {Function} A callback function
     to be used (instead of the builtin `tls.checkServerIdentity()` function)
     when checking the server's hostname (or the provided `servername` when