Seemingly Random Drops/Disconnects

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HRDevOps
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Seemingly Random Drops/Disconnects

Post by HRDevOps » Wed Apr 08, 2020 5:27 pm

Good morning!

This is my first post on this forum, so if I break any rules with this post, please let me know and I'll rectify it ASAP.

I'm currently experiencing an issue with OpenVPN Connect Beta v3.1.1(378). I am able to successfully connect to the server and for the most part, the connection works great. It will however, seemingly randomly, drop and immediately reconnect. We've noticed this in several ways:

  • Windows Remote Desktop would disconnect, forcing reconnect attempts which immediately go through
  • SSH connections receive the "connection closed unexpectedly"
  • Join.Me users see "Reconnecting..." for half a second, frequently
  • Slack disconnects (Seen by all contacts going offline, then online again)
Since this issue has arisen, I've tried playing with the client settings including: Seamless Tunnel, TCP/UDP/Adaptive, TLS versions, etc. but to no avail. I've also tried adjusting my MTU (client side only) to no avail. The logs in the OpenVPN client do not update/add any logs when these drops happen. I've cleared it and literally watched the drop happen and nothing populate in the logs.

Does anyone have any suggestions on how to fix this issue? Its been plaguing my developers, and myself as I use SSH quite often and the connection closes before scripts can finish running, etc. If you need me to provide any config/log info, please let me know! I'll respond as quickly as possible.

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Pippin
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Re: Seemingly Random Drops/Disconnects

Post by Pippin » Wed Apr 08, 2020 5:38 pm

Is this Access Server or Community version?
Your client is more aimed for Access Server.

Sounds more like network related, latency, speed perhaps.
Also try this client:
https://openvpn.net/community-downloads/
I gloomily came to the ironic conclusion that if you take a highly intelligent person and give them the best possible, elite education, then you will most likely wind up with an academic who is completely impervious to reality.
Halton Arp

HRDevOps
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Posts: 6
Joined: Wed Apr 08, 2020 5:19 pm

Re: Seemingly Random Drops/Disconnects

Post by HRDevOps » Wed Apr 08, 2020 6:24 pm

Thanks for the response! I'm going to give the other client a try and let you know if it makes a difference

I believe this is Access Server

HRDevOps
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Re: Seemingly Random Drops/Disconnects

Post by HRDevOps » Wed Apr 08, 2020 6:26 pm

No luck with that other client. Used the same .ovpn used to set up my OpenVPN Connect Beta v3.1.1(378) client for what its worth. After a few minutes, the PuTTY SSH session crapped out with the same message.

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Pippin
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Re: Seemingly Random Drops/Disconnects

Post by Pippin » Wed Apr 08, 2020 6:29 pm

Try add

Code: Select all

mssfix 1400
to the client config.

Does your server have a GUI?
https://openvpnasserverip:943
I gloomily came to the ironic conclusion that if you take a highly intelligent person and give them the best possible, elite education, then you will most likely wind up with an academic who is completely impervious to reality.
Halton Arp

HRDevOps
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Posts: 6
Joined: Wed Apr 08, 2020 5:19 pm

Re: Seemingly Random Drops/Disconnects

Post by HRDevOps » Wed Apr 08, 2020 6:36 pm

Sorry, I should've mentioned that I tried that as well. In my current ovpn file, I added mssfix 1430 after doing that command - 40 thingy. I'll try changing it to 1400 and letting you know if it makes a difference. Just to be clear to be sure I have it in the right place, here is a snippet of the .ovpn file where I placed it:

reneg-sec 604800
sndbuf 0
rcvbuf 0
# NOTE: LZO commands are pushed by the Access Server at connect time.
# NOTE: The below line doesn't disable LZO.
comp-lzo no
verb 3
setenv PUSH_PEER_INFO
mssfix 1430

My server also does have a GUI. I've not attempted and server side fixes yet as I currently have about 80 users connected but would be willing to try some things after work hours.

EDIT: No dice on the mssfix 1400. I made sure to delete and reimport the profile so that it would take effect as well. Just to be clear, this was in the OpenVPN Connect Beta client, not the one you provided.

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Pippin
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Re: Seemingly Random Drops/Disconnects

Post by Pippin » Wed Apr 08, 2020 6:53 pm

The place is alright.

Code: Select all

seemingly randomly, drop and immediately reconnect
Do more users experience this?
80 users, you have sufficient bandwidth and hardware server side?
I gloomily came to the ironic conclusion that if you take a highly intelligent person and give them the best possible, elite education, then you will most likely wind up with an academic who is completely impervious to reality.
Halton Arp

HRDevOps
OpenVpn Newbie
Posts: 6
Joined: Wed Apr 08, 2020 5:19 pm

Re: Seemingly Random Drops/Disconnects

Post by HRDevOps » Wed Apr 08, 2020 7:11 pm

Yep. Our sales reps utilize Join.Me for software demos and all of them notice the "Reconnecting issue". All of our devs utilize SSH connections to our staging websites and all experience the "Remote side unexpectedly closed connection." While some of their connections are pretty bad/questionable, there are enough users with reliable internet that experience the same issues, which tells me that its more of a config problem.

Through our firewall/network monitoring solution I can't see any correlation between our internet bandwidth usage and the drops in connection, that is, no maxing out of internet connections, etc. Our building hosting the server has a 100/100 connection.

Got some quick and dirty specs from my coworker who set up the server:
ubuntu 18 vm
dynamic ram (1-4GB) - hovers at 1GB
2 vcores
dedicated nic

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Pippin
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Re: Seemingly Random Drops/Disconnects

Post by Pippin » Wed Apr 08, 2020 7:18 pm

Join.me, screen sharing, I would certainly suspect bandwidth or hardware.
Specifically single core CPU speed.

You could submit a ticket, please read here:
https://openvpn.net/vpn-server-resource ... r-openvpn/
I gloomily came to the ironic conclusion that if you take a highly intelligent person and give them the best possible, elite education, then you will most likely wind up with an academic who is completely impervious to reality.
Halton Arp

HRDevOps
OpenVpn Newbie
Posts: 6
Joined: Wed Apr 08, 2020 5:19 pm

Re: Seemingly Random Drops/Disconnects

Post by HRDevOps » Wed Apr 08, 2020 7:20 pm

Gotcha. I'll have my buddy bump up the cpu allocation to the server and see if that makes a difference, though he mentioned it never really goes above 1% utilization, nor ~1.1GB RAM utilization.

Any settings in the admin GUI you'd suggest messing around with?

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Pippin
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Re: Seemingly Random Drops/Disconnects

Post by Pippin » Wed Apr 08, 2020 7:36 pm

OpenVPN is single threaded, thus again single core CPU speed is important.
Adding cores won't help unless the server is doing other tasks taking resources.
AES-NI support is a big plus also,

Code: Select all

grep aes /proc/cpuinfo
I have no experience with Access Server but the underlying is pretty much the same as Community version.
I gloomily came to the ironic conclusion that if you take a highly intelligent person and give them the best possible, elite education, then you will most likely wind up with an academic who is completely impervious to reality.
Halton Arp

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