[Solved] Skype does not connect

costel78 · Guru Joined: 20 Apr 2007 Posts: 402

Since two days ago I encountered a very strange problem: skype is no longer available in the network.
I mean to anyone, no matter what OS we are using, or what device: PC, tablet, phone etc.

It is definitely a ISP error, but I don't know where to start.
Facts:
1. ping to skype.com is working very well
2. mtr to skype.com, also working
3. telnet skype.com 80 is connecting and there thing are starting to go strange...
From skype.com or www.skype.com I receive 301 - Moved permanently and I am redirected to go.skype.com. From there I got ERR_CONNECTION_TIMEOUT

My local ISP ask for my help, since I am since long time Linux user.
So, their setup is:
Their ISP (Telekom.ro) gave them two VLANS - one for external bandwith, one for metropolitan (peering) and they have a established BGP session, but with a PRIVATE AS number.
They do not have their purchased, public, ASN.
For vlans they are using two /30 ip classes owned by telekom.ro
Clients have a separate, public IP C class - /24
I tried multi DNS servers starting with own telekom.ro to google and opendns. I am sure it is not a DNS issue.

From server itself links http://[www.]skype.com is working, from clients nada...
People from my ISP told me that since ~ 1 week ago they started to not beeing able to access some sites.
It is sound to me as a BGP issue, but telekom.ro pretending that everything is ok from their part. I do not know, maybe it is...

What do you think ? Where to start ?

Oh, from server itself skype.com is available, but when I run

Roman_Gruber · Posted: Sat Aug 08, 2015 5:50 pm Post subject:

wireshark / etherreal or whatever that stuff is called.
fire up skype and check what is needed.

or check skype / mirnosoft homepage and see waht they demand ...

costel78 · Guru Joined: 20 Apr 2007 Posts: 402

Well, net-analyzer/wireshark does not help because server is not reacheble.
There are only skype api request to connect, but no response, whatsoever.

Interesting thing, throught: we did a server reboot. After reboot, when all services was already started and bgp routes reciewed, suddenly a boy of one ISP employer said "Skype is working" on his tablet. We were able to test by calling to Echo test service, but, during the call, skype disconnected.
We repetead procedure server reboot, skype waiting to connect and, yes it reconnected again for ~40s.
_________________
Sorry for my English. I'm still learning this language.

Roman_Gruber · Posted: Sat Aug 08, 2015 8:40 pm Post subject:

In my understanding a network sniffer is useful to analze software.

I used etherreal in year 2000 for some purposes. You should be able to see whats going on and than be able to give feedback or do something.
it helps to have less or nothing running except the network analzyer and skype.

anything else is up to you, to disagree or whatever...

also this little baby helped me also several times

[I] net-analyzer/iptraf-ng
Available versions: 1.1.4-r1^t (~)1.1.4-r2^t **9999^t {doc}
Installed versions: 1.1.4-r2^t(09:54:04 24.08.2014)(-doc)
Homepage: http://fedorahosted.org/iptraf-ng/
Description: A console-based network monitoring utility

costel78 · Guru Joined: 20 Apr 2007 Posts: 402

Problem solved. With help from wireshark. Thank you!
As I told previously, initial packet capturing didn't help because there were only requests from my part. No response, whatsoever, from skype.
But when I run wireshark during a web browsing session to www.skype.com I noticed a DNS request. Response was correct, but BGP routing directed that to metropolitan instead of external connection.
I manually deleted route and skype connected instantly.
I left to them to sort/figure problem with telekom.ro to prevent that to happen again.

Thank you!
_________________
Sorry for my English. I'm still learning this language.

Roman_Gruber · Posted: Sun Aug 09, 2015 2:21 pm Post subject:

common etiquette is that the topic poster edit the title of his first post and add [solved] when your issue is solved, thanks.