MULTI: Outgoing TUN queue full, dropped packet len=x

smigal_aus

Hi all,

sorry if I'm in the wrong section or if this has been answered before.

I'm having some trouble, I am a newbie and my training is more in electronics than networking so I'm struggling my way through this.

I have a teltonika RUT240 Cellular modem that will be the client as we want to connect these behind the ISP 's NAT. I want to connect a tunnel to a windows 10 server (it may change to windows 2106 server in the future)

I have managed to get it talking over an OpenVPN connection, however every 20 seconds I get a 5 second pause on the network connection and the server logs:

Mon Feb 17 15:52:58 2020 Client1/203.196.93.229:46545 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 15:52:58 2020 Client1/203.196.93.229:46545 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 15:52:58 2020 Client1/203.196.93.229:46545 MULTI: Outgoing TUN queue full, dropped packet len=44

..... approx 28 times every pause.

port 1194
proto tcp4
dev tun

ca "C:\\Program Files\\OpenVPN\\config\\ca.crt"
cert "C:\\Program Files\\OpenVPN\\config\\ServerVPN.crt"
key "C:\\Program Files\\OpenVPN\\config\\ServerVPN.key"
dh "C:\\Program Files\\OpenVPN\\config\\dh2048.pem"

server 10.8.0.0 255.255.255.0

keepalive 10 120
cipher AES-128-GCM
#comp-lzo

persist-key
persist-tun
verb 5

client-config-dir "C:\\Program Files\\OpenVPN\\config\\ccd"
ifconfig-pool-persist "C:\\Program Files\\OpenVPN\\log\\ipptxt" 5

and the teltonika configuration is:

https://drive.google.com/file/d/1LoppYuZhLaua2iTxC1Flw15u6VKiQW-q/view?usp=sharing

Mon Feb 17 12:36:59 2020 --pull-filter ignored for --mode server
Mon Feb 17 12:36:59 2020 OpenVPN 2.4.8 x86_64-w64-mingw32 [SSL (OpenSSL)] [LZO] [LZ4] [PKCS11] [AEAD] built on Oct 31 2019
Mon Feb 17 12:36:59 2020 Windows version 6.2 (Windows 8 or greater) 64bit
Mon Feb 17 12:36:59 2020 library versions: OpenSSL 1.1.0l  10 Sep 2019, LZO 2.10
Enter Management Password:
Mon Feb 17 12:36:59 2020 MANAGEMENT: TCP Socket listening on [AF_INET]127.0.0.1:25341
Mon Feb 17 12:36:59 2020 Need hold release from management interface, waiting...
Mon Feb 17 12:37:00 2020 MANAGEMENT: Client connected from [AF_INET]127.0.0.1:25341
Mon Feb 17 12:37:00 2020 MANAGEMENT: CMD 'state on'
Mon Feb 17 12:37:00 2020 MANAGEMENT: CMD 'log all on'
Mon Feb 17 12:37:00 2020 MANAGEMENT: CMD 'echo all on'
Mon Feb 17 12:37:00 2020 MANAGEMENT: CMD 'bytecount 5'
Mon Feb 17 12:37:00 2020 MANAGEMENT: CMD 'hold off'
Mon Feb 17 12:37:00 2020 MANAGEMENT: CMD 'hold release'
Mon Feb 17 12:37:00 2020 Note: cannot open C:\Program Files\OpenVPN\log\ipptxt for READ/WRITE
Mon Feb 17 12:37:00 2020 Diffie-Hellman initialized with 2048 bit key
Mon Feb 17 12:37:00 2020 Failed to extract curve from certificate (UNDEF), using secp384r1 instead.
Mon Feb 17 12:37:00 2020 ECDH curve secp384r1 added
Mon Feb 17 12:37:00 2020 interactive service msg_channel=632
Mon Feb 17 12:37:00 2020 ROUTE_GATEWAY 192.168.254.1/255.255.255.0 I=13 HWADDR=6c:62:6d:c3:b7:6f
Mon Feb 17 12:37:00 2020 open_tun
Mon Feb 17 12:37:00 2020 TAP-WIN32 device [Local Area Connection 2] opened: \\.\Global\{B8FE8647-C699-4E35-8123-9BC5BFEF4FC3}.tap
Mon Feb 17 12:37:00 2020 TAP-Windows Driver Version 9.24 
Mon Feb 17 12:37:00 2020 Notified TAP-Windows driver to set a DHCP IP/netmask of 10.8.0.1/255.255.255.252 on interface {B8FE8647-C699-4E35-8123-9BC5BFEF4FC3} [DHCP-serv: 10.8.0.2, lease-time: 31536000]
Mon Feb 17 12:37:00 2020 Sleeping for 10 seconds...
Mon Feb 17 12:37:10 2020 Successful ARP Flush on interface [25] {B8FE8647-C699-4E35-8123-9BC5BFEF4FC3}
Mon Feb 17 12:37:10 2020 MANAGEMENT: >STATE:1581903430,ASSIGN_IP,,10.8.0.1,,,,
Mon Feb 17 12:37:10 2020 MANAGEMENT: >STATE:1581903430,ADD_ROUTES,,,,,,
Mon Feb 17 12:37:10 2020 C:\WINDOWS\system32\route.exe ADD 10.8.0.0 MASK 255.255.255.0 10.8.0.2
Mon Feb 17 12:37:10 2020 Route addition via service succeeded
Mon Feb 17 12:37:10 2020 Socket Buffers: R=[65536->65536] S=[65536->65536]
Mon Feb 17 12:37:10 2020 Listening for incoming TCP connection on [AF_INET][undef]:1194
Mon Feb 17 12:37:10 2020 TCPv4_SERVER link local (bound): [AF_INET][undef]:1194
Mon Feb 17 12:37:10 2020 TCPv4_SERVER link remote: [AF_UNSPEC]
Mon Feb 17 12:37:10 2020 MULTI: multi_init called, r=256 v=256
Mon Feb 17 12:37:10 2020 IFCONFIG POOL: base=10.8.0.4 size=62, ipv6=0
Mon Feb 17 12:37:10 2020 IFCONFIG POOL LIST
Mon Feb 17 12:37:10 2020 MULTI: TCP INIT maxclients=60 maxevents=64
Mon Feb 17 12:37:10 2020 Initialization Sequence Completed
Mon Feb 17 12:37:10 2020 MANAGEMENT: >STATE:1581903430,CONNECTED,SUCCESS,10.8.0.1,,,,
Mon Feb 17 12:39:37 2020 TCP connection established with [AF_INET]203.196.93.229:46472
Mon Feb 17 12:39:38 2020 203.196.93.229:46472 TLS: Initial packet from [AF_INET]203.196.93.229:46472, sid=2b1ae593 59c03977
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 VERIFY OK: depth=1, C=AU, ST=ACT, L=Canberra, O=OpenVPN, OU=changeme, CN=C4Server, name=changeme, emailAddress=garth@sitech.com.au
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 VERIFY OK: depth=0, C=AU, ST=ACT, L=Canberra, O=OpenVPN, OU=changeme, CN=Client1, name=changeme, emailAddress=garth@sitech.com.au
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_VER=2.4.5
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_PLAT=linux
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_PROTO=2
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_NCP=2
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_LZ4=1
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_LZ4v2=1
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_LZO=1
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_COMP_STUB=1
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_COMP_STUBv2=1
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 peer info: IV_TCPNL=1
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 Control Channel: TLSv1.2, cipher TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 4096 bit RSA
Mon Feb 17 12:39:41 2020 203.196.93.229:46472 [Client1] Peer Connection Initiated with [AF_INET]203.196.93.229:46472
Mon Feb 17 12:39:41 2020 Client1/203.196.93.229:46472 MULTI_sva: pool returned IPv4=10.8.0.6, IPv6=(Not enabled)
Mon Feb 17 12:39:41 2020 Client1/203.196.93.229:46472 MULTI: Learn: 10.8.0.6 -> Client1/203.196.93.229:46472
Mon Feb 17 12:39:41 2020 Client1/203.196.93.229:46472 MULTI: primary virtual IP for Client1/203.196.93.229:46472: 10.8.0.6
Mon Feb 17 12:39:42 2020 Client1/203.196.93.229:46472 PUSH: Received control message: 'PUSH_REQUEST'
Mon Feb 17 12:39:42 2020 Client1/203.196.93.229:46472 SENT CONTROL [Client1]: 'PUSH_REPLY,route 10.8.0.1,topology net30,ping 10,ping-restart 120,ifconfig 10.8.0.6 10.8.0.5,peer-id 0,cipher AES-256-GCM' (status=1)
Mon Feb 17 12:39:42 2020 Client1/203.196.93.229:46472 Data Channel: using negotiated cipher 'AES-256-GCM'
Mon Feb 17 12:39:42 2020 Client1/203.196.93.229:46472 Outgoing Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
Mon Feb 17 12:39:42 2020 Client1/203.196.93.229:46472 Incoming Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
Mon Feb 17 12:39:59 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:39:59 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:39:59 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:39:59 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=84
Mon Feb 17 12:39:59 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:39:59 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:39:59 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:00 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:00 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:00 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=84
Mon Feb 17 12:40:00 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:00 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:00 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=84
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:01 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=84
Mon Feb 17 12:40:02 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:02 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:02 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:02 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:02 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:02 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=84
Mon Feb 17 12:40:02 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:04 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:04 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:04 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=44
Mon Feb 17 12:40:04 2020 Client1/203.196.93.229:46472 MULTI: Outgoing TUN queue full, dropped packet len=84

Any help is sincerely appreciated. Please let me know if there is any other info that might make this easier.

Cheers

Garth

Pippin

To your server config, add

tcp-queue-limit 128

restart and try again.

smigal_aus

Thanks Pippin,

I appreciate your time.

I tried that but unfortunately there was no change in the result. It kept doing the same thing.

Cheers though

TinCanTech

Just to confirm, are you using version 2.4.8-i602 ?

Found here:
https://openvpn.net/community-downloads/

smigal_aus

Confirmed
Version 2.4.8-i602

Cheers

TinCanTech

In my experience, errors like this are generally caused by your computer network not being setup correctly. For example, using ethernet and wifi at the same time but having the OS (eg. Windows) constantly interfering because it thinks it knows better than the user what it should do.