Internet Traffic Routing Problems in Spain

September 1, 2008

I had a call from a client today who said that her mailĀ  in outlook was not working however she does have internet connection and can see web sites.

I thought that was rather strange and I asked her to login to the webmail login via her web browser. She said she could not see the webmail login page either. I also asked her to type the actual IP of the web browser just to make doubly sure. Again, no luck.

Strange. She can get web sites, cant get email, cant see the online login page. Maybe her IP is being blocked by our mail server firewall, because our mail server automatically blocks dodgy activities and closes down the IP.

So I logged into the mail server firewall to check if her IP was blacklisted, but no, nothing there either.

I myself could see the mail server via my browser and I don’t have any issues with my mail either so I was beginning to get a little stumped.

Saying that, earlier on before the call from the client, I did notice that a couple of regular sites that I use were not working for meĀ  and I just shrugged that off as they must be doing web site maintenance or something but it occured to me that maybe its something else.

Like many others here in Spain, I use telefonica as my adsl provider and they have given me a nice fat 20MB line, but, I am a business and I need internet 24/7 so I have a backup router which uses Vodafone 3G. So I switched over to the Vodafone line and guess what? The sites that I was having problems with suddenly started working.


But…..this does not mean that its telefonicas fault 100% but “some” fault lies with them. Why? Well they provide you with the adsl within Spain but they also pay a fee for your traffic to go via other providers, in this case a company called DTAG which is Deutsche Telecom.

if you click on the image below you will see a result of a traceroute from my local machine in Spain to one of our mail servers located in New York.

Traceroute Example from Spain to the US

You will see that there is a time out after the packets leave the telefonica network which means there is a problem with hop 6 which could either belong to telefonica or deutsche telecom.

The only way to find out is to contact either provider, but shall we waste time with that?

No because by the time you contact Telefonica and explain the problem, it usually gets resolved anyway.

If its still the same tommorrow, then I would contact them otherwise just ride it out.