Can't connect from another host (bindIp 127.0.0.1) MongoDB Origin: Data OSI layer 4 · Transport Last updated 5 Nov 2026

MongoDB: connection refused / timed out from a remote host — mongod bindIp defaults to 127.0.0.1

MongoDB only listens on localhost by default, so remote clients can't connect.

Exact message you may see MongoDB remote connection refused bindIpmongod only listening on 127.0.0.1MongoNetworkError: connect ETIMEDOUT <remote>:27017couldn't connect to server remote host:27017 connection refusedMongoServerSelectionError: connect ETIMEDOUT
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Seen on: MongoDB Linux

Meaning

Set net.bindIp: 127.0.0.1,<private-ip> in /etc/mongod.conf, restart, and open the port only to trusted hosts via firewall/security group. Enable authentication and TLS first — never expose MongoDB without auth (bindIp: 0.0.0.0 on the public internet gets hijacked).

Common causes

  • bindIp left at 127.0.0.1
  • Firewall/security group blocks 27017
  • Cloud private network not configured
  • mongod config not reloaded
  • Auth not enabled when opening

⚡ Quick fix

  1. Edit /etc/mongod.conf: net: { port: 27017, bindIp: 127.0.0.1,10.0.0.5 } and sudo systemctl restart mongod
  2. Open 27017 only to app servers
  3. Enable security.authorization: enabled

Detailed fix by platform

Linux

  1. sudo ss -ltnp | grep mongod and nc -vz DB_IP 27017 from the client

Code examples

/etc/mongod.conf

yaml
net:
  port: 27017
  bindIp: 127.0.0.1,10.0.0.5     # never 0.0.0.0 on a public IP without firewall + auth
security:
  authorization: enabled

How to diagnose

  1. Bind — Interfaces listed?
  2. Firewall — Port restricted?
  3. Auth — Enabled?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: Data. Errors that are often confused with or caused by this one (click to open):

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