Teamviewer 15 takes a very looooong time to connect.

[Linares]

Teamviewer can sometimes take up to an hour to connect and display the list of computers. From when I open the application, until the list of computers appears, waiting can be desperate.
When I am not going to manage a remote computer, it is not important to have that message for so long:
"Teamviewer is starting. Wait...
It's not ready. Check your connection."
But when I need to control another PC (knowing that the connection is perfect because you are browsing the internet) and it is necessary to wait 15, 20 or 30 minutes, it is exasperating.
What could be the cause of this delay?

teamviewer pensando.gif (68.33 KiB) Viewed 3549 times

[isadora]

Not an answer for your question, but just an advise.
I struggled with Teamviewer a lot the last years, and found a good alternative in Anydesk.
https://anydesk.com/en/downloads/linux

[doktor5000]

Hello. I know that in Linux there are better alternatives than TeamViewer, but I have been using it with my family (geographically dispersed) for more than 5 years, and I have a network with many Windows / Ubuntu / Lubuntu / Mageia computers ... Thanks, Isadora, for your suggestion, but now It would be a nuisance to replace machine-by-machine this application.

[isadora]

Fair enough, as meant, just a suggestion.

[doktor5000]

Have you tried asking your question to teamviewer support ?

[jiml8]

I don't use teamviewer so I can't offer a real suggestion about it.

But, given the symptoms you describe I would start by looking at my firewall to determine if it was blocking a port that teamviewer needs. That strikes me as the most likely cause.

When I have to remotely control one of my desktops, I use tightvnc with an ssh tunnel. Works perfectly and is secure. I can even control my workstation desktop from my Android phone this way (though it is tedious...)

Just a thought...

[Linares]

I don't use teamviewer so I can't offer a real suggestion about it.

But, given the symptoms you describe I would start by looking at my firewall to determine if it was blocking a port that teamviewer needs. That strikes me as the most likely cause.

The suggestion is good, but I don't use a firewall, at least, as far as I know.

[doktor5000]

So iptables -L as root does not return any rules ?

[Linares]

So iptables -L as root does not return any rules ?

Code: Select all

# iptables -L
Chain INPUT (policy DROP)
target     prot opt source               destination         
Ifw        all  --  anywhere             anywhere           
net-fw     all  --  anywhere             anywhere           
ACCEPT     all  --  anywhere             anywhere           
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type BROADCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type ANYCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type MULTICAST
LOG        all  --  anywhere             anywhere             limit: up to 1/sec burst 10 mode srcip LOG level info prefix "INPUT REJECT "
reject     all  --  anywhere             anywhere            [goto]

Chain FORWARD (policy DROP)
target     prot opt source               destination         
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type BROADCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type ANYCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type MULTICAST
LOG        all  --  anywhere             anywhere             limit: up to 1/sec burst 10 mode srcip LOG level info prefix "FORWARD REJECT "
reject     all  --  anywhere             anywhere            [goto]

Chain OUTPUT (policy DROP)
target     prot opt source               destination         
fw-net     all  --  anywhere             anywhere           
ACCEPT     all  --  anywhere             anywhere           
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type BROADCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type ANYCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type MULTICAST
LOG        all  --  anywhere             anywhere             limit: up to 1/sec burst 10 mode srcip LOG level info prefix "OUTPUT REJECT "
reject     all  --  anywhere             anywhere            [goto]

Chain Ifw (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere             match-set ifw_wl src
DROP       all  --  anywhere             anywhere             match-set ifw_bl src
IFWLOG     all  --  anywhere             anywhere             ctstate INVALID,NEWpsd weight-threshold: 10 delay-threshold: 10000 lo-ports-weight: 2 hi-ports-weight: 1 IFWLOG prefix 'SCAN'

Chain dynamic (1 references)
target     prot opt source               destination         

Chain fw-net (1 references)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     all  --  anywhere             anywhere           

Chain logdrop (0 references)
target     prot opt source               destination         
DROP       all  --  anywhere             anywhere           

Chain logflags (7 references)
target     prot opt source               destination         
LOG        all  --  anywhere             anywhere             limit: up to 1/sec burst 10 mode srcip LOG level info ip-options prefix "logflags DROP "
DROP       all  --  anywhere             anywhere           

Chain logreject (0 references)
target     prot opt source               destination         
reject     all  --  anywhere             anywhere           

Chain net-fw (1 references)
target     prot opt source               destination         
dynamic    all  --  anywhere             anywhere             ctstate INVALID,NEW,UNTRACKED
tcpflags   tcp  --  anywhere             anywhere           
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type BROADCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type ANYCAST
DROP       all  --  anywhere             anywhere             ADDRTYPE match dst-type MULTICAST
LOG        all  --  anywhere             anywhere             limit: up to 1/sec burst 10 mode srcip LOG level info prefix "net-fw DROP "
DROP       all  --  anywhere             anywhere           

Chain reject (4 references)
target     prot opt source               destination         
DROP       all  --  anywhere             anywhere             ADDRTYPE match src-type BROADCAST
DROP       all  --  base-address.mcast.net/4  anywhere           
DROP       igmp --  anywhere             anywhere           
REJECT     tcp  --  anywhere             anywhere             reject-with tcp-reset
REJECT     udp  --  anywhere             anywhere             reject-with icmp-port-unreachable
REJECT     icmp --  anywhere             anywhere             reject-with icmp-host-unreachable
REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain sha-lh-64dafc7872d69fd91b74 (0 references)
target     prot opt source               destination         

Chain sha-rh-68587fdaa31c74d4f49f (0 references)
target     prot opt source               destination         

Chain shorewall (0 references)
target     prot opt source               destination         
           all  --  anywhere             anywhere             recent: SET name: %CURRENTTIME side: source mask: 255.255.255.255

Chain tcpflags (1 references)
target     prot opt source               destination         
logflags   tcp  --  anywhere             anywhere            [goto]  tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,PSH,URG
logflags   tcp  --  anywhere             anywhere            [goto]  tcp flags:FIN,SYN,RST,PSH,ACK,URG/NONE
logflags   tcp  --  anywhere             anywhere            [goto]  tcp flags:SYN,RST/SYN,RST
logflags   tcp  --  anywhere             anywhere            [goto]  tcp flags:FIN,RST/FIN,RST
logflags   tcp  --  anywhere             anywhere            [goto]  tcp flags:FIN,SYN/FIN,SYN
logflags   tcp  --  anywhere             anywhere            [goto]  tcp flags:FIN,PSH,ACK/FIN,PSH
logflags   tcp  --  anywhere             anywhere            [goto]  tcp spt:0 flags:FIN,SYN,RST,ACK/SYN

[jiml8]

yeah, you have rules. That looks like a default shorewall installation.

I don't see anything that is port specific in these rules, though it is blocking incoming broadcast/anycast/multicast traffic. This is common and I really doubt that teamviewer does that anyway.

I don't see the chain tcp in this rules list; not sure where it is though it is referenced several places and is key to how shorewall is handling inbound traffic. I would expect to find that almost all inbound traffic is dropped unless specifically allowed, either via an established connection or via a port being opened.

So there is quite a good chance that the other end of your connection is not allowing it.

To quickly establish whether this is the case, you might try (as root) executing this command: "service shorewall stop" on both systems, then see if you can connect.

After running the test, you should definitely run "service shorewall start" on both systems to restart the firewall.

If the connection happens quickly when the firewalls are off, then you've found your problem. Otherwise, you have to look somewhere else.

[isadora]

Hi.
I just completed a test following your instructions.
While the message "Teamviewer is starting. Wait ... It's not ready. Check your connection." was on my screen, I opened terminal on both computers.

In this computer, Mageia 7:

Code: Select all

# service shorewall stop
Redirecting to /bin/systemctl stop shorewall.service

On the computer I intend to access, Ubuntu 18:
"Failed to stop shorewall.service: Unit shorewall.service not loaded".

Y, por supuesto, el mensajito aún sigue ahí.

I close TeamViewer, I try to open it again from KDE, but it doesn't react. I try to open it from terminal and receipt:

Code: Select all

[root@localhost teamviewer]# ./teamviewer

Init...
CheckCPU: SSE2 support: yes
Checking setup...
Launching TeamViewer ...
Starting network process (no daemon)
Network process already started (or error)
Launching TeamViewer GUI ...

But it doesn't launch.

[doktor5000]

On the computer I intend to access, Ubuntu 18:
"Failed to stop shorewall.service: Unit shorewall.service not loaded".

Y, por supuesto, el mensajito aún sigue ahí.

Only english, please
And that command was meant for a Mageia box. You would need to find the equivalent of disabling the firewall on your Ubuntu box.

Apart from that, why do you run teamviewer as root ?

[isadora]

Oh, sorry, I forgot to translate that specific phrase into English.

"Y, por supuesto, el mensajito aún sigue ahí." means "And, of course, the message is still there."

I don't remember why, at that moment in particular, I ran Teamviewer as root but, when I run it without root, the result is the same.