VPN trouble

Hi Erwin,

 

I would say that a firmware update on the o2 router might cause these problems (although it should not).

 

How are the Fritzboxes connected to the internet? Does the one that runs behind the o2 router establish an own internet connection via PPPoE-Passthrough? If not that might help.

 

regards

nemesis03

Can you try to replace the 6431 trough the Fritzbox? You will only be able to use the internet, telephony will be impossible. (If you can’t make it work, please ask)

If VPN works without the 6431, you know the reason.

The firtz! is a 7170. So connecting it directly is not an option. 

No changes in the config. And it was running reliably. suddenly it did not work anymore. a couple of months ago this happened to a PPTP vpn connection that I had running stable for months.

 

I feel there is a conspiracy going on!!

 

Anyway, i does not work anymore. And it could be either O2 or telekom. It is getting complicated. 

 

Is there a reliable and good VDSL provider in Berlin that is not driven by commercial goals?

 

E

Good suggestions, I already did the reset. The alternative I use right now is via SSL. however streaming of media is not possible via this connection. 

 

I tried openVPN (pc to pc) in the past, but that did not work.

 

The VPN link was to the Netherlands. There I have a provider called XS4ALL. I guess the name says it all... Extremely flexible, a lot of great and new initiatives, and amazing customer support. And a 100mbit up/down glasfiber connection! 

 

 

I have been playing around this weekend. The VPN connection was setup again and connection is realised. Still the 

 

So I tried it with the Fritz vpn software for windows. VPN connected well, but throughput is 2kb/s. 

 

So I tried an alternative. Bittorent sync, which worked fine in the past. it connected well, but throughput is 2kb/s. 

 

So I see a pattern and that is that any program using UDP is blocked. 

 

So I tried Webdav, since this is uses TCP. And that confirmed that my UDP ports are blocked, since downloads went up to >1Mb/s.

 

Now I saw that since January 7, the fair use policy has been changed. That could well be the reason. if you use more than a certain volume, your download speed is reduced. I received no notification or nothing. I am shocked that this is allowed in Germany. I will try to cancel my connection asap.

 

 

 

 

 

 

 

 

 

Miracles happen. Since about 30 minutes the connection is back and downloads are possible. VPN works again as well as bittorrent sync. Still the speed is very low; <250kb/s.

 

What is going on here????

 

Did you send a private message to o2_dsl? Then lets wait for their answer.

https://

That did not last long.... 7 minutes

Complicated questions (and this is a complicated question) can take a few days. Did you look in the Posteingang whether there is an answer (by default there is no email notification)? And when you go to Gesendete Nachrichten and click on your message you can see whether an when the message has been read.

That is bad luck.

In the moment we do not know where the problem really ist. It might be

• the 6431 blocking UDP-traffic, but I'm wondering why you are the only one that is having difficulties
• the "o2-VDSL-servers" that block UDP-Traffic or the ports
• one of your Fritzboxes that is faulty
• the ISP on the other end of the ISP that is somehow blocking something
• a server somewhere on the route that is faulty

I think if the 6431 or the o2-servers are blocking UDP-traffic on purpose, then there shouldn't be times when the connection is working.

 

Maybe you should just by a vdsl-modem and see whether that solves your problem. Of course you cannot use the telephone line while you are using another vdsl-modem (unless you read-out the sip-account-information).

 

And you cannot expect the helpdesk to give you enterprise-support on a highly complicated question. I think there are companys that will give you enterprise-support, but they are much more expensive than the 30-40 Euro per month you pay o2.

 

And at the moment there is no proof that o2 is at fault.

Did you already try to establish a vpn-connection using a neighbors internet connection?

I checked the connections. I can't even ping the destination via UDP; however i can via TCP. I checked various port ranges. TCP is open, UDP is closed. 

 

The MTU is only relevant for the size of the packets sent over the internet. The higher the MTU, the faster the connection. But also I higher risk of packets not arriving.

 

In my case all UDP ports are blocked. I traced the packages and these are stopped in the O2 infrastructure. For 2 weeks there was no issue. VPN worked flawless. And I never change a working configuration. 

 

O2 is blocking UDP trafic.

 

O2 needs to unblock the UDP trafic

 

It is soooo simple. O2 solve my issue.

nemesis03 schrieb:Maybe there is only an echo over TCP but not over UDP. Did you also try this from a not-o2-connection? If your theory is right then the ports should be open when you use another ISP.

I have no issues when I go via another provider.

The MTU is also relevant if packets are too large and have to be fragmented to be send over the internet. That might cause problems, if fragmentation is prohibited. And I think the maximum MTU on the internet is 1500 including all headers. So a MTU of 1550 would be slower than for example 1450, because the packets would be fragmented.

The optimal MTU for my connection is 1420.

This is the first time that you mention a trace. Can you please post the traces and the pings you did and tell us with which programs you did them.

 

If you want you can send me the address of your server in a private message and I will try the same tests from my internet line and maybe from my university (if I have access to the required programs).

I used netscan pro. ping on port 80. A website is running on this port and can be reached.

TCP results

Pinged xxx.homeserver.com [82.161.xxx.xxx] with SYN packets.
Start Time: Sun, 26 Jan 2014 16:44:36
ANALYSIS:Target reached by one or more packets.
Outgoing Packet DS Bits: 000 000 ECN: 00
5 packets transmitted, 5 packets received, 0% packet loss
Round Trip Time - min/avg/max = 83.407/85.019/87.019 (ms)

 

ICMP results

Pinged xxx.homeserver.com [82.161.xxx.xxx] with 32 data bytes
Start Time: Sun, 26 Jan 2014 16:56:37
ANALYSIS:Target reached by one or more packets.
Outgoing Packet DS Bits: 000 000 ECN: 00
5 packets transmitted, 5 packets received, 0% packet loss
Round Trip Time - min/avg/max = 65.827/78.049/94.394 (ms)

 

UDP results

Pinged xxx.homeserver.com [82.161.xxx.xxx] with 32 data bytes
Start Time: Sun, 26 Jan 2014 16:57:26
ANALYSIS:Target not reached. Press Settings and try increasing TTL and Timeout values.
If that does not help, the target might have an ICMP filter in place or be offline.
Outgoing Packet DS Bits: 000 000 ECN: 00
5 packets transmitted, 0 packets received, 100% packet loss

 

 

 

 

 

If you can prove that on o2-server is blocking the udp-traffic there might be a chance that a ticket for the technical support will be opened.

 

It would be interesting if it is only this server that is blocking udp-traffic. There is a chance that traffic from my dsl-connection in Hamburg will not go through this server, so maybe udp-traffic from my connection will not be blocked (or blocked by another server).

I am getting confused now. So there is a technical support??? So far I have only received a reaction from a moderator named Matze who clearly is not willing to provide any help in any way.

 

The point is that it suddenly stopped working, whereas it was working before. I did not make any changes to the setup. 

 

If you are routed via another server it might well be possible for the time being. However that does not solve my issue. It still could be that silly router that O2 provides, but replacing it with another one will make me loose the telephone line. 

 

In short, O2 is not delivering a working internet connection and does not provide any customer service. O2 is the worst provider ever and does not provide any customer service.