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No internet connection, all router lights are green and I can ping websites

A
Besucher:in
Hi, sorry for not writing in German but my German is still not very good.

Since last Monday, I cannot connect to the Internet with any device. The router has all lights green, I can connect perfectly vis wi-fi and lan to the router, the router webpage shows "Freischaltung: o2 Homebox ist freigeschaltet" and "Online-Status: Verbunden". Everything looks fine and I can even execute ping to any webstie from my terminal (e.g. ping www.google.com) without any problem from more than one computer.

However, I cannot load any webpage nor send any TCP packages from any device. Moreover, I have tried executing traceroute from my Mac newtork utility tool. There, for any webpage I try, the hops of the packets alway start with two telefonica IPs after my router and my IP adress, for example:

3: ae15-0.0002.dbrx.02.ber.de.net.telefonica.de (62.53.12.5/61)
4: ae1-0.0002.prrx.02.ber.de.net.telefonica.de (62.53.12.61)

And then they continue hoping until the destination webpage. I have also tried executing telnet (e.g. telnet www.google.com 80) but cannot connect with it.

It looks like either TCP is misconfigured somewhere or there is some telefonica firewall that is redirecting all my traffic somewhere and not allowing me to receive TCP packages from the network to my router, even if my internet connection is fine.

My router is an o2 HomeBox 6441. I have tried disconnecting all cables from the router for hours and connecting them back and resetting the router to default without success, all the time all lights are green but the same issue happens: cannot connect at al except sending ping to websites and traceroute to them.

Lösung von o2_Lars

See this thread.
Regards,
Lars
    Zu diesem Thema können keine neuen Antworten hinzugefügt werden. Du kannst gern ein eigenes Thema erstellen.

    16 Antworten

    A
    • Anonymous
    • May 2, 2019
    Moin Moin,
    go to System Preferences -> Network -> Advanced
    Check TCP/IP
    should be
    Using DHCP try "Renew HDCP Lease"
    Check your IP should be from 192.168.1.2 to 192.168.1.250
    Subnet 255.255.255.0
    Router 192.168.1.1
    Go to Tab DNS and check if 192.168.1.1 is in the list.
    Go to Tab Proxies "every thing" should be unmarked!
    Any fire walls installed on you Mac?? Little Snitch?

    If you connect to www.googel.com via Telnet an you get "nothing" than type get followed by retrun.
    Than you should get
    code:
    HTTP/1.0 400 Bad Request
    Content-Type: text/html; charset=UTF-8
    Referrer-Policy: no-referrer
    Content-Length: 1555
    Date: Thu, 02 May 2019 18:34:23 GMT


                   
                                   
                                                         
                      Error 400 (Bad Request)!!1
                                                                 
                                                                            *{margin:0;padding:0}html,code{font:15px/22px arial,sans-serif}html{background:#fff;color:#222;padding:15px}body{margin:7% auto 0;max-width:390px;min-height:180px;padding:30px 0 15px}* > body{background:url(//www.google.com/images/errors/robot.png) 100% 5px no-repeat;padding-right:205px}p{margin:11px 0 22px;overflow:hidden}ins{color:#777;text-decoration:none}a img{border:0}@media screen and (max-width:772px){body{background:none;margin-top:0;max-width:none;padding-right:0}}#logo{background:url(//www.google.com/images/branding/googlelogo/1x/googlelogo_color_150x54dp.png) no-repeat;margin-left:-5px}@media only screen and (min-resolution:192dpi){#logo{background:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) no-repeat 0% 0%/100% 100%;-moz-border-image:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) 0}}@media only screen and (-webkit-min-device-pixel-ratio:2){#logo{background:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) no-repeat;-webkit-background-size:100% 100%}}#logo{display:inline-block;height:54px;width:150px}
          
                    
                                                                                           400. That Ç s an error.
                 Your client has issued a malformed or illegal request.  That Ç s all we know.



    A
    A
    Besucher:in
    • aitor4p
    • Autor
    • Besucher:in
    • May 2, 2019
    Thank you for your answer!

    Everything that you mentioned is fine and I have no firewall installed. During telnet, the request times out and tries a variety of IPs without success (Unable to connect to remote host), so I cannot send any request at all like GET/.

    It is definitely not an issue with my mac: I have another laptop, two phones, one xbox and one smart speaker connected to the Wi-fi which cannot connect to the Internet. They all were connected perfectly until this Monday evening.

    To me, it seems like some O2 firewall set before data arrives from the Internet to my router is misconfigured and dropping my connections. Since ping works with ICMP and traceroute with UDP, it might be that it is dropping all TCP connections ( I also see packets from IGMP and ARP). I have no way to check that I think, someone from O2 could check it.
    A
    • Anonymous
    • May 2, 2019
    It looks like you are in Berlin. I think if they have a problem in berlin the will have a lot of calls...
    And they will not have any fire wall to expensive...
    Do you have Teamspeak on your mac?
    Try to reach www.polykrates.net
    A
    B
    Legende
    Forum|alt.badge.img+20
    • blablupLegende
    • Legende
    • May 2, 2019
    If all lights on a o2 Homebox 6441 are green, something is wrong. At least the INFO-LED should be off and not green.
    If your telephone is working but not your internet connection, the connection could be blocked by o2. Please check your bank account, if everything is paid (to the correct o2 bank account).
    A
    A
    • Anonymous
    • May 2, 2019
    If all lights on a o2 Homebox 6441 are green, something is wrong. At least the INFO-LED should be off and not green.
    If your telephone is working but not your internet connection, the connection could be blocked by o2. Please check your bank account, if everything is paid.
    @blablup
    von der Idee super. Aber die lassen dann ein Ping zu aber keine Verbindung über port 80?
    B
    Legende
    Forum|alt.badge.img+20
    • blablupLegende
    • Legende
    • May 2, 2019
    Keine Ahnung, hatte noch keine Sperre. Der Test mit dem Telefon dürfte aber schneller gehen, als darüber nachzudenken. Vielleicht ist das auch für die Telefonie notwendig, wer weiß?
    A
    Besucher:in
    • aitor4p
    • Autor
    • Besucher:in
    • May 2, 2019
    Sorry, the info light is not green. Only Telefon, DECT, DSL, Internet, Wlan and Power. Unfortunatelly I don't have a telephone attached to the router at home to try that.

    Yes, I am in Berlin. It might be that it is some issue near my flat or that my line has some configuration problem in some routing/firewall.. just trying to have some hypothesis. Definitely not something affecting many people because that would have been fixed fast.

    No, I don't have Teamspeak.. but with Netstat in network utility from my Mac I see UDP packages been sent, so anything UDP can potentially work.
    A
    • Anonymous
    • May 2, 2019
    ich würde dann erwarten das man das Routing aus dem O2 Netz verindert.
    Der Sip Server steht am im "Intranet"...
    A
    • Anonymous
    • May 2, 2019
    @aitor4p Are you able to connect to the url above?
    A
    A
    Besucher:in
    • aitor4p
    • Autor
    • Besucher:in
    • May 2, 2019
    I have tried to ping it but all I get is request timeouts. Also, for traceroute it reaches ips from telefonica in Hamburg but from there all the hops timeout. Telnet is also not able to connect, nor is any of my browsers.

    Vielen Dank euch beiden für eure Zeit und Hilfe 🙂
    A
    • Anonymous
    • May 2, 2019
    I will not answer ping. Please try safari. The server is in the O2 Network. So there should be no routing out of the O2 Network. U will get the wather from Hamburg.
    A
    A
    Besucher:in
    • aitor4p
    • Autor
    • Besucher:in
    • May 2, 2019
    I just tried with Safari, Chrome and Firefox and did not receive the webpage. I can connect with my 4g connection through my phone and see the weather page, but not with wifi.

    Also, when I connect with my smartphone to the wifi it detects ("Wi-Fi without internet access"). This is the same as when in an airport you connect to a wifi network that requires a login in some airport webpage before working (or here in berlin the BVG wifi network in the U-Bahn before accepting terms and conditions).
    A
    • Anonymous
    • May 2, 2019
    Hmmm strange.
    If you are able to speak with the german support?
    Störungsannahme
    O2 DSL Telefon
    0800 52 51 37 8 Kostenfrei
    A last thing you could tray...
    Download the O2 DSL Help App could be faster than phone and waiting of O2 Forum Admin...
    Otherwise you have to wait for some one from @o2_DSL ...
    A
    Besucher:in
    • aitor4p
    • Autor
    • Besucher:in
    • May 2, 2019
    Yesterday it was a free day and today I could 't call before 20:00, I will try calling tomorrow and/or Saturday if this is not fixed. I will try to use that app, thank you for the link :)

    To add something, I have tried the DNS service via UDP with nslookup and it works fine (e.g. for google.com) but if I do "set vc" (that uses DNS service via TCP) I get no answer and timeouts... So it definitely is a problem with TCP while UDP is working
    A
    Besucher:in
    • aitor4p
    • Autor
    • Besucher:in
    • May 2, 2019
    As an update, I have used wireshark from my laptop to track the network traffic.

    Every protocol except TCP works fine (ARP, DNS, ICMP, IGMPv2, SSDP). I can send TCP traffic between two of my devices connected to the router (for example xbox and laptop) and they are actually communicating via http to share my laptop screen with my xbox. Howeveer, every TCP request to an external IP fails and continuously retries with a TCP retransmission packet.

    So it is not an internal problem with TCP, but something blocks all incoming/outgoing TCP packets (but not from other protocols) from the internet to my router and viceversa.
    o2_Lars
    • o2_LarsModerator
    • Moderator
    • Lösung
    • May 13, 2019
    See this thread.
    Regards,
    Lars
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