Troubleshooting remote mongodb connections
My mongo server on Digital Ocean (DO) appears to be accepting connections correctly, but my PC does not see the ip & port as open with an nmap. The server is receiving connections without issues from a different server on DO.
What is especially odd is that this was working perfectly fine and suddenly stopped.
There is a small possibility that this is interfering - I setup port forwarding and DynDNS with my router. “Small possibility” because i’m 85% sure I had this issue before setup of port forwarding & ddns. I thought it was just the changing of my local ip address and I would just need to add it to the mongo server ufw again.
On the Mongo Server
root@mongo:~# ufw status Status: active To Action From -- ------ ---- 22/tcp LIMIT Anywhere 80/tcp ALLOW Anywhere 443/tcp ALLOW Anywhere 27017 ALLOW [-- other server ip address that works --] 27017 ALLOW [-- local machine ip address --] OpenSSH ALLOW Anywhere 27017 ALLOW Anywhere 27017 ALLOW [-- local public ip address --] 22/tcp (v6) LIMIT Anywhere (v6) 80/tcp (v6) ALLOW Anywhere (v6) 443/tcp (v6) ALLOW Anywhere (v6) OpenSSH (v6) ALLOW Anywhere (v6) 27017 (v6) ALLOW Anywhere (v6)
root@mongo:~# nmap [-- mongo server ip address --] -p 27017 Starting Nmap 7.60 ( https://nmap.org ) at 2020-08-05 17:32 UTC Nmap scan report for mongo ([-- mongo server ip address --]) Host is up (0.000036s latency). PORT STATE SERVICE 27017/tcp open mongod Nmap done: 1 IP address (1 host up) scanned in 0.25 seconds
root@mongo:~# netstat -plnt Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN 694/systemd-resolve tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 924/sshd tcp 0 0 [mongo ip]:27017 0.0.0.0:* LISTEN 2040/mongod tcp 0 0 127.0.0.1:27017 0.0.0.0:* LISTEN 2040/mongod tcp6 0 0 :::22 :::* LISTEN 924/sshd
On my Local PC
myusername@mb ~ % nmap [-- mongo server ip address --] -p 27017 Starting Nmap 7.80 ( https://nmap.org ) at 2020-08-05 13:30 EDT Nmap scan report for [-- mongo server ip address --] Host is up (0.024s latency). PORT STATE SERVICE 27017/tcp filtered mongod Nmap done: 1 IP address (1 host up) scanned in 0.43 seconds
There is something going on in between these machines that I haven’t caught. I need this to CRUD my production database locally.
Things I’ve tried:
- Removing and adding back the ip address from ufw
- Making 27017 allowed from anywhere (as seen above; previously restricted to only specific ips)
- Listening for connections on 27017 with nc localhost 27017 (have not heard anything)
- ufw disable - still returns filtered on local PC.
- Disabled the DynDNS
- Added 27017 to my router’s firewall.
- Testing nmap through a VPN
None of these have worked.
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