Network connectivity problem

[acobo]

Hello all,
My Dreambox 7000S is not able to connect to Internet, and after a lot of tests, I don’t know what else to try, any help will be very appreciated.
I am using the Hydra Lucien image. The problem is that the DB seems not to be connected at all: I cannot download keys, addons or softcams (I get “download failed” or the DB hangs) ; Links web-browser only shows a blank page, the Weather plugin says: “timeout, data not available”, etc. However, I have tried to connect the DB to the LAN of my workplace, and everything works OK, I am able to download everything OK!
I have a small LAN at home, with three computers with Windows and the Dreambox. The connection WITHIN the home network is OK: I can access the Dreambox with Dreambox Control Center, by Telnet, FTP, HTPP, upload new images, ... everything works fine, so it seems a problem with the Internet access, routing, or something related.
BUT, I have done the following tests:
-I have tried to access the DB from my workplace to my home, using Telnet, FTP and HTPP, at it works always (I can see the HTTP page, transfer files by FTP, do a Telnet session, …)
-I can do Telnet from my dreambox to any external server in Internet, also, without problems.
-pings to the other computers inside the home network are OK, but pings to the ADSL router or computers beyond result in duplicated echoes (sometimes, up to 40% of the packets are duplicated, other a few percent, but I always get duplicated echoes).

I think that the problem come from the wireless bridge (802.11b) located between my wired home network and the ADSL router (and hence, the Internet), which is only 50meters long. I am using two “paired” access points from USRobotics, one as an access point and the other as a wireless client. The weird thing is that I haven’t notice any problem in two years with this wireless bridge, before having the Dreambox. All network services (pings, web browsing, …) in the three computers are running OK.

It seems that the problem is due to a particular way that the Linux box do the networking (all other computers are running WinXP or Win98), but I am not a expert in Linux.
I have look to ifconfig for errors, but I get always the same: (BTW, TX and RX bytes is always zero, is it ok?)

/tmp > ifconfig
eth0 Link encap:Ethernet HWaddr 00:09:34:10:1E:34
inet addr:192.168.1.31 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:28 Base address:0xa300 DMA chan:ff

While looking to netstat when trying to download something, the TCP connection stays as “ESTABLISH” forever:

/tmp > netstat -n
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 192.168.1.31:1969 203.55.158.114:80 ESTABLISHED
tcp 0 0 127.0.0.1:12405 127.0.0.1:1274 CLOSE_WAIT
tcp 0 0 192.168.1.31:23 192.168.1.3:4483 ESTABLISHED
tcp 32 0 127.0.0.1:80 127.0.0.1:1970 ESTABLISHED
tcp 0 0 127.0.0.1:1970 127.0.0.1:80 ESTABLISHED
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags Type State I-Node Path
unix 3 [ ] STREAM CONNECTED 9757 /tmp/camd.socket
unix 3 [ ] STREAM CONNECTED 9756

I’m sorry for the long explanation. Any help will be welcome!
Thanks in advance,
Adolfo.

[xelayb]

Hi,

I think that is not a image problem. The duplicate packets is done by other network component in your network, this component answer the packets. You can put your dreambox directly connect to ADSL router and try connect.

[musicbob]

Set the Nameserver (on Network setup of Lucien image) to:

Nameserver = 195.210.128.3

then try again to download from internet
It solved for me, had your same problem.

[acobo]

Thanks to all who replied,
Xelayb: Yes, I think that some network component between the DB and my ISP is not working ok, duplicating packets, but.... ¿why it only happens with the dreambox and not with the other three windows computers? The only thing different could be the MTU, but I have already tried to change it.
Musicbob: thanks for the idea, but I have changed the nameserver to several addresses and it doesn't work
Keep trying...

[digge]

Are you shure the signal strength is good and without interference? Cause wireless equipment use another access method to the medium and unlike usual cable you have to acknowledge each "packet" wich gets resent if no acknowledge is recived.

Maybe thats your problem but its just a wild guess on my side. Like have you installed any wireless phones or something lately, for me that broke my wireless equipments range by half or it wouldnt work at all. Try to just slightly move around the antennas and see if it gets better...

[xelayb]

Originally Posted by acobo

Thanks to all who replied,
Xelayb: Yes, I think that some network component between the DB and my ISP is not working ok, duplicating packets, but.... ¿why it only happens with the dreambox and not with the other three windows computers? The only thing different could be the MTU, but I have already tried to change it.
Musicbob: thanks for the idea, but I have changed the nameserver to several addresses and it doesn't work
Keep trying...

I don’t know your diagram network, are PC and DM the some network segment ? Can you put the Ethereal (Data analysis) to get it? But I've resolved problem with cisco 7200 VX ios, it duplicate packets in multicast configuration, and sometime the pc or network has the multicast started as default.

[acobo]

Originally Posted by xelayb

I don’t know your diagram network, are PC and DM the some network segment ? Can you put the Ethereal (Data analysis) to get it? But I've resolved problem with cisco 7200 VX ios, it duplicate packets in multicast configuration, and sometime the pc or network has the multicast started as default.

Xelayb:
PCs and DB are all connected to the same 10/100 ethernet switch, then the uplink of this switch connected to a WIFi AP in client mode, which connect my small home wired LAN to the ADSL router and the Internet. I haven't notice any connectivity problem with the other three PCs in two years. In fact, I have tried to download the SAME URL that the Dreambox is trying to get from another PC, at the SAME moment, and the file reachs the PC in a few seconds, while the Dreambox stays stuck.

Attached to this reply are two ethereal captures: "wget_a_remote_url.zip" is the traffic captured when the dreambox (192.168.1.31) tried to download a new control panel for the hydra image. Yo can see that the HTTP GET command is issued, then the remote server replied with TCP ACK, but the HTPP 200 OK reply never comes.

The second capture is "wget_a_local_webpage"; for this, I have manually entered a "wget" command in the dreambox to retrieve the index.html page located in a local web server (actually, the web server of Emule in the PC at home, 192.168.1.4 -DB IP address is 192.168.1.31 as before-) . In this case, everything is OK!!!!!

Then, I have tried to download a web page of my ISP (www.ya.com), from the DB, and it works also!, so I cannot blame the ADSL ruoter or some other equipment of my own.

I don't know what to think. Today, I bet for a Time-to-live-like problem, but not of the IP protocol but of the linux HTTP protocol implementation. But, surely, there is no a TTL equivalent at the HTTP protocol level, so....

Anyway, thanks for your help. I keep thinking...

[xelayb]

Hi,

Sorry my late. I saw your trace, but I saw nothing special things. I think that the server either doesn’t complete the http protocol or the HTTP protocol is wrong in image. Now I’m working, and I can’t make the same test in DM. The DM has nothing to test the network, as lynx (web browser in command line), telnet client, and more. I want help to resolve the network problem without specific image, but this moment, without resources, is hard. Can you test other image? RuDream has many different links to Internet, and we will can conclude if the problem will be image.