Assigning multiple IP addresses to MongoDB 7.0 on Ubuntu

Question

The Problem

I am trying but failing, in MongoDB 7.0, on Ubuntu, to bind multiple IP addresses to net.bindIp in mongod.conf

What I have tried

I have tried 127.0.0.1,x.x.x.x, 127.0.0.1;x.x.x.x, [127.0.0.1,x.x.x.x], [127.0.0.1;x.x.x.x] and mongod fails to start on each and everyone.

when the syntax is

[127.0.0.1,x.x.x.x] I get this error

Aug 22 11:52:36 ip-172-26-1-93 mongod[41708]: Scalar option 'net.bindIp' must be a single value

and when I use any other syntax, I get this error

Aug 22 11:54:38 ip-172-26-1-93 mongod[41723]: {"t":{"$date":"2023-08-22T11:54:38.935Z"},"s":"I",  "c":"CONTROL",  "id":7484500, "ctx":"main","msg":"Environment variable MONGODB_CONFIG_OVERRIDE_NOFORK == 1, overriding \"processManagement.fork\" to false"}

Where I have looked

After searching this extensively, I found this answer here and the answers to this question here and after tryin their solutions I still get the same errors.

I have looked at the documentation for the latest version and I can't see where I am going wrong.

Additional

I can successfully bind 0.0.0.0, however this then defeats the object of using net.bindIp

Edit

I have tried reinstalling MongoDB 3 times now, and still the same issue

@mustaccio yes I have. I have tried every possible variation of the [] / [x,x] / [x;x] and x,x / x;x / x, x syntax and I either get 'scalar option 'net.bindIp must be a single value' or it fails to start the daemon. I have edited the question to say I have also tried reinstalling the MongoDB instance. — Yenmangu, Aug 22 '23 at 15:10
I haven't test with latest versions, but earlier versions there was "feature" that if there was even one space character in that bindIp, it failed. 192.168.2.29,127.0.0.1 — JJussi, Aug 22 '23 at 16:57
yes, I have tried all possible variations of the syntax with spaces and without spaces — Yenmangu, Aug 22 '23 at 17:06
rob@ip-172-26-1-93:~$ ifconfig ens5: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 9001 inet 172.26.1.93 netmask 255.255.240.0 broadcast 172.26.15.255
BUT thats not the IP address that I have assigned to my DNS. Im using AWS Lightsail if its any help. — Yenmangu, Aug 26 '23 at 16:59
So, you have only one interface. In this case net.bindIpAll: true will do exactly the same. What do you mean by "assigned to my DNS"? — Wernfried Domscheit, Aug 26 '23 at 17:56
@WernfriedDomscheit oh my bad I was reading it totally wrong. Okay sure thanks — Yenmangu, Aug 26 '23 at 22:46

jelongpark · Answer 1 · 2024-03-14T14:05:11.953

The bindIP should be the ip address or hostname of the host. The mongod cannot bind an ip addrress of another host. This should be the relevant section on each host.

https://www.mongodb.com/community/forums/t/socketexception-cannot-assign-requested-address/10964

In most cases, you can use localhost, 127.0.0.1, and the server name. Otherwise, just 0.0.0.0 for all the IP or hostnames that are assigned to the host server if the server has multi IP addresses or multi hostnames.

score -1 · Answer 2 · answered Aug 22 '23 at 17:58

Actually there is no reason to assign multiple IP-Addresses. This makes only sense on a computer with multiple network interfaces. However, since MongoDB does not support multiple network interfaces, it would be pointless anyway.

Either use net.bindIpAll: true if you like to permit connections from remote machines or use net.bindIp: localhost if you need to permit connections only from the local machine.

Anything else does not make much sense.

Assigning multiple IP addresses to MongoDB 7.0 on Ubuntu

2 Answers2