Part-3-c Suggestion: add DNS troubleshooting note for ETIMEOUT errors on Atlas connection

[Matt-Anis]

When trying to connect to MongoDB Atlas, some students may encounter this error:

node mongo.js <password>
/home/user/node_modules/mongoose/lib/drivers/node-mongodb-native/collection.js:142
            const err = new MongooseError(message);
                        ^
MongooseError: Operation `notes.insertOne()` buffering timed out after 10000ms
    at Timeout._onTimeout (.../node-mongodb-native/collection.js:142:25)
    at listOnTimeout (node:internal/timers:605:17)
    at process.processTimers (node:internal/timers:541:7)
Node.js v24.14.0

Which after further investigation leads to:

Error: queryTxt ETIMEOUT notesdb.ntx0c91.mongodb.net

Root cause:

The ETIMEOUT error on the DNS TXT lookup means the machine can't resolve the Atlas hostname. This is caused by ISPs in certain regions (North Africa, Middle East, etc.) blocking MongoDB Atlas's DNS or routing entirely, it's not a code issue.

Fix:

Switch to a public DNS resolver (e.g. Cloudflare 1.1.1.1 or Google 8.8.8.8)

Suggestion:

A small troubleshooting note in the Atlas setup section mentioning this error and the DNS fix would save students in affected regions a lot of time.

thanks :)