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Slow internet connection every 10 days
Hello, all. What happens is a bit weird so let me explain.
Every 10 to 12 days, usually after noon, internet speed goes almost to a standstill. When I try to go to, let’s say www.google.com on the bottom left of the browser I get messages “… trying to resolve host” etc.
If i try to ping an outside IP address or domain name most of the time i get time outs or if i dont time out the speed is like 1500ms.
If I connect my laptop directly to my Router/Modem then the speed is normal again.
This happens only to computers connected wired or wirelessly to the domain/network.
The topology of the network is as follows.
One Cisco X3000 Modem/Router Connected to an HP Switch providing internet.
Also X3000 is the DHCP provider to the premises. All other computers, printers have manually entered IPs. Also as Gateway they have router’s IP and as DNS1 the server’s IP
One Windows server as Domain Controller and DNS server. In server’s network card as Default Gateway there is the IP (192.168.0.150) of the router and as a DNS1 its own IP (192.168.0.100).
As for the forwarders I have the IP of the providers DNS and Google’s.
And that’s it. I can’t figure out what is wrong with my network. It’s very weird that this happens only once in a while so it’s hard to pinpoint the problem.
I have checked if someone is downloading something big etc. No luck.
Also I have checked with our provider if our DSL line is ok and every time it checks out.
Thank you for the assistance.
Dionisis.
Every 10 to 12 days, usually after noon, internet speed goes almost to a standstill. When I try to go to, let’s say www.google.com on the bottom left of the browser I get messages “… trying to resolve host” etc.
If i try to ping an outside IP address or domain name most of the time i get time outs or if i dont time out the speed is like 1500ms.
If I connect my laptop directly to my Router/Modem then the speed is normal again.
This happens only to computers connected wired or wirelessly to the domain/network.
The topology of the network is as follows.
One Cisco X3000 Modem/Router Connected to an HP Switch providing internet.
Also X3000 is the DHCP provider to the premises. All other computers, printers have manually entered IPs. Also as Gateway they have router’s IP and as DNS1 the server’s IP
One Windows server as Domain Controller and DNS server. In server’s network card as Default Gateway there is the IP (192.168.0.150) of the router and as a DNS1 its own IP (192.168.0.100).
As for the forwarders I have the IP of the providers DNS and Google’s.
And that’s it. I can’t figure out what is wrong with my network. It’s very weird that this happens only once in a while so it’s hard to pinpoint the problem.
I have checked if someone is downloading something big etc. No luck.
Also I have checked with our provider if our DSL line is ok and every time it checks out.
Thank you for the assistance.
Dionisis.
Who is Participating?
Does your ISP provide you with a fixed IP public address or do you get it via DHCP?
How long is the slow down? A few minutes, a few hours, the whole day?
How long is the slow down? A few minutes, a few hours, the whole day?
Is there a way you can to a packet capture on the HP switch of the port the modem is on?
Sounds almost like somebody is doing a backup every 10 days of of something.
Sounds almost like somebody is doing a backup every 10 days of of something.
How can I do that? I thought that too. The packet capturing. During the slowdown it would be great if I could see the traffic. There is a piece of hardware that every now and then communicates with a remote location but both user and the engineer responsible for it assured me that this was not the case.
Sorry but I can't answer that right now. But i'm pretty sure its manageable. I'll return tomorrow morning for the model. If it is manageable I can monitor traffic right?
If you go into DNS console on server and restart the DNS server service does that remedy the issue or does internet remain slow? If resolves issue then you may need to schedule DNS cleanup.
I've tried that and it will not help. If I powercicle the router for 2-3 minutes internet speed might return to normal and then back to oblivion...
If it is manageable you should be able to do.
What you would do is configure the switch to mirror the traffic for the port that the modem is on.
The connect a PC to that port and run Wireshark to capture the packets.
What you would do is configure the switch to mirror the traffic for the port that the modem is on.
The connect a PC to that port and run Wireshark to capture the packets.
You want to look to see if any host is generating a TON of traffic. That is enough traffic to eat up all of your Internet bandwidth.
Once you find that out, then you need to find what that host is doing.
Once you find that out, then you need to find what that host is doing.
Ok i've captured 1012 packets. Of which 236 are UDP connections to external IP's from the server. 114 are from a user and many more are outgoing connections from the server to external IP's.
Do give you an example the following are incoming connections(many of them):
48 7.817920000 85.72.92.200 192.168.0.100 UDP 112 Source port: 60858 Destination port: odeumservlink
1012 94.929498000 79.129.16.89 192.168.0.100 UDP 176 Source port: 50546 Destination port: odeumservlink
And the following are outgoing connections:
931 88.319408000 192.168.0.100 79.129.16.89 UDP 112 Source port: odeumservlink Destination port: 57985
943 89.163910000 192.168.0.100 85.72.92.200 UDP 112 Source port: odeumservlink Destination port: 60858
Also one thing that i forgot to mention is that on the server is running Hamachi. Someting that i have to use...
Do give you an example the following are incoming connections(many of them):
48 7.817920000 85.72.92.200 192.168.0.100 UDP 112 Source port: 60858 Destination port: odeumservlink
1012 94.929498000 79.129.16.89 192.168.0.100 UDP 176 Source port: 50546 Destination port: odeumservlink
And the following are outgoing connections:
931 88.319408000 192.168.0.100 79.129.16.89 UDP 112 Source port: odeumservlink Destination port: 57985
943 89.163910000 192.168.0.100 85.72.92.200 UDP 112 Source port: odeumservlink Destination port: 60858
Also one thing that i forgot to mention is that on the server is running Hamachi. Someting that i have to use...
If the UDP traffic "disappears" from the packet capture then that is most likely your problem.
I believe that Hamachi I believe it uses UDP to setup VPN connections. So what do you use VPN for?
Could your server be VPN'ing outbound to distribute "information" or to do a backup every 10 days?
If possible I would check to see if that server has a task that is scheduled to run every 10 days.
I believe that Hamachi I believe it uses UDP to setup VPN connections. So what do you use VPN for?
Could your server be VPN'ing outbound to distribute "information" or to do a backup every 10 days?
If possible I would check to see if that server has a task that is scheduled to run every 10 days.
Hamachi is used by our 2 abroad offices. We have a CRM Software and Hamachi emulates local network connection for these two offices. But from time to time i see errors in event viewer about printer drivers i dont have in my network.
I thing i have to blame Hamachi for this...
Right now i have dissabled Hamachi but network speed is still slow...
Any way... i have to go now. Thanks for your help. I'll get back to you on Monday.
Have a great weekend!!
I thing i have to blame Hamachi for this...
Right now i have dissabled Hamachi but network speed is still slow...
Any way... i have to go now. Thanks for your help. I'll get back to you on Monday.
Have a great weekend!!
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You have a good weekend too.