Railway Silent Packet Drop to MongoDB Atlas — Fixes

Hi @mathieupilonlauzon-dotcom,

You've done an excellent diagnostic job. The fact that port 27017 works fine to portquiz.net but silently drops to Google Cloud Atlas IPs points to one of two things: either Google Cloud is filtering Railway's shared egress IP range, or there's a routing issue on Railway's side for Google Cloud-owned prefixes. Either way, here are the actionable fixes ranked by effort.

1. Static Outbound IP (recommended, lowest effort)

Railway now supports dedicated static egress IPs. This gives your service a clean, single IP not shared with other tenants, which almost always bypasses reputation-based filtering.

• Go to your service dashboard → Outbound Networking → Enable Static IP
• Requires at least the Hobby plan ($5/mo credit)
• After enabling, verify the new IP with curl -s ifconfig.me from the Railway web console
• Add the new IP to your Atlas IP Access List (or keep 0.0.0.0/0)

This is the most likely fix — a fresh dedicated IP won't be on whatever blocklist is causing the silent drop.

2. SOCKS/SSH proxy via a cheap VPS (no Railway plan change)

If upgrading the plan isn't an option, route MongoDB traffic through a lightweight proxy on any VPS:

# On a $3-5/mo VPS (Hetzner, DigitalOcean, etc.)
ssh -N -D 0.0.0.0:1080 user@your-vps-ip

Then in your Python app, use PyMongo with a SOCKS proxy:

import socks
import socket
from pymongo import MongoClient

socks.set_default_proxy(socks.SOCKS5, "your-vps-ip", 1080)
socket.socket = socks.socksocket

client = MongoClient("mongodb+srv://...")

Or simpler — set up a TCP proxy on the VPS that forwards localhost:27017 → Atlas, and point your Railway app at the proxy endpoint.

3. MongoDB Atlas Data API (driverless, no port 27017)

Atlas has a Data API that exposes collections over standard HTTPS (port 443). Since general outbound from Railway works fine (your curl google.com returns 200), this completely sidesteps the issue.

• Enable in Atlas UI → Data Services → Data API
• Replace PyMongo driver calls with HTTP requests via the Data API SDK
• No port 27017 involved — everything goes over port 443

Downside: requires code changes to replace direct driver queries with REST calls.

4. Railway support escalation

Your thread already has the question-bounty tag and detailed diagnostics. If Railway engineers can rotate your service to a different egress IP or investigate their NAT routing to Google Cloud prefixes, that's the zero-effort fix. But given the 3-day silence, I'd pursue option 1 in parallel.

TL;DR

1. Static Outbound IP — 5 min · Hobby+ plan · Success: Very high

→ A fresh dedicated IP almost always escapes shared-IP reputation filtering.

2. VPS proxy — 30 min · ~$3-5/mo · Success: High

→ Route MongoDB traffic through a cheap VPS tunnel. No Railway plan change needed.

3. Atlas Data API — 1-2 hours (code changes) · Free · Success: Very high

→ Bypasses port 27017 entirely, uses standard HTTPS/443.

4. Wait for support — Unknown · Free · Success: Medium

→ Railway may rotate your egress IP or fix routing. 3 days already passed with no response.

Start with #1 (Static Outbound IP). It takes 5 minutes and costs nothing beyond the Hobby plan's $5 monthly credit.

Disclaimer: I don't work for Railway — just helping troubleshoot as a community member.