Networking :: Keep Losing Connection On Ethernet Card With Public IP's
Feb 11, 2009
I have a very strange problem with my Linux Router/Firewall machine where i keep losing my connection on the ethernet card.
I have installed a Debian 4 distro on a PC with 2 nics to create a router/firewall machine. On nic-1 i have connected the ADSL modem and on nic-2 a laptop for testing.
What i want is to build a DMZ with public IP addresses assigned to the servers in DMZ.
Schematic example:
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We have a total of 16 Public IP's assigned to the ADSL modem from our ISP configured in routering mode. Unfortunately our new ISP does not support Bridge mode, otherwise i would not have this problem. (we had modem in bridge mode working fine with our old ISP, but they have stopped so we were forced to switch to another ISP. eth1 and eth2 both have public IP addresses from the modem set hardcoded in the /etc/network/interfaces on Linux pc and on my testlaptop in the DMZ (server-1) i have set another public IP (they all fall in the same network range) I have enabled IP forwarding on Linux router/firewall and for testing the firewall is set to allow all traffic.
When i try to ping the testlaptop in my DMZ from a remote machine outside in our datacenter i get no reply.
However when i run the following command: ip addr add xx.xx.xx.xx dev eth1 to assign the public IP i have chosen for the laptop to the inner nic (eth2) and then try to ping the testlaptop again from the remote machine it still does not reply ... but (and here is the most bizar thing)...
When i then run the following command: ip addr del xx.xx.xx.xx dev eth1 (where xx.xx.xx.xx is the ip of the testlaptop) and try to ping again from the remote machine then it seems to be working fine ... however only for a short time because then connection is lost somehow.
I have a Linux box being used as a firewall with Fedora 10 and shorewall 4.2.10. Secondary IPs are loaded on the WAN (eth1)card through Shorewall NAT and Rules file. The problem is that if there is a network hickup or if the circuit bounces, the primary IP comes back but I have to reload Shorewall to get the secondary ips back. Is there a way so that they can automatically reload or just not go away if the connection bounces?
I'm trying to set up a shared Internet connection that had been broken by a previous update, I believe. Eth0 is connected to the Internet, whereas eth2 should be the connection going to my Roku set-top box. Under the nm-applet icon, an entry exists for "Auto eth0" for the first card, but there is nothing under the second card except "disconnected". How do I make a connection entry under my eth2 card so that I can share my Internet connection with my Roku box?
I'm using Xubuntu 8.10, network-manager, Atheros AR2413 802.11bg NIC, and Radeon Xpress 200M with open-source ati drivers.
My problem is that I'm frequently losing my internet connection--whether I'm wired or wireless. It happens most often when I'm watching a ..... video but it happens other times too. My cpu usage is high when watching ..... (70-100%), so that may have something to do with it but I'm here because I really don't know.
I started having this problem when I switched from the proprietary fglrx driver to the ati driver. I switched because my laptop was always freezing halfway through a movie using vlc/mplayer. The ati fixed this but gave me my current problem. I do not want to go back to fglrx.
Here's what I've done so far to try to fix it without success:
-tried using noapci boot option -tried using a different router -tried using wicd
When I lose the connection I still have a strong signal. My lshw and iwconfig outputs are the same as before I lose my connection. However, I cannot ping my router when I lose the connection. I have to reboot to reconnect.
I just installed fedora 10 on a machine with a netgear ga311 gigabyte Ethernet card. Usually when I start it up I have a connection but after 5 minutes I lose the connection.
A friend of mine is running Ubuntu. He used to run Windows XP, but he kept destroying it completely, and I soon got tired of fixing it for him. So I setup Ubuntu, and we're both happier people for it.BUT! The other day he asked me to setup a VPN (PPTP) connection to his workplace, which I promptly did. It also just works, except for one minor problem: When he fires up the VPN connection, I lose the ability to connect to his computer over SSH. As soon as he shutdown the VPN connection, I can once again log in over SSH.I use the SSH connection for basic maintenance and for tunneling port 5900 so I can assist him over VNC.
His nic is setup with DHCP. Gateway is 192.168.57.1. Port 22 is NAT'ed to 192.168.57.2, which is the IP his computer is assigned by the router (it's reserved to his MAC address).
When he connect the VPN, a new interface is created with the IP 192.168.1.32. I'm very much _not_ a network expert. I can manage the very basic stuff, but beyond that I'm quite lost.
I installed 10.3 (after buying it a couple of years ago and letting sit on the shelf) and can't get it to configure my ethernet connection or my wireless card. Yast doesn't include a list of available cards, and the error I get in installation-network setup is that the kernel isn't present. The machine I'm installing this on is a Lenovo, in which there isn't a discrete ethernet card (it's in the motherboard), but my wireless card (a Cisco LINKSYS 802.11G) is a discrete card. Because I'm divorcing Microsoft for a number of valid reasons, I don't have Windows available on that box.
Just installed Fedora 14 from the Live CD i686 on my Dell Inspiron 1521. I can't connect to the SpeedTouch 585 on either wireless broadcom card or the wired Ethernet card.
I can connect to it from the same Laptop on the Vista which is on dual boot on the same laptop.
Further confusing is that I ran Fedora 14 and connected to another SpeedTouch today.
Already checked the Channel on the wireless nic and it's on the same one as the SpeedTouch.
I am running Karmic AMD64 on a homebrew desktop PC, but I also previously had this trouble on 32 bit with different hardware and on Ubuntu 9.04 and 8.10. The router is now an ADSL+ Thomson TG585n supplied by O2 and badged O2 Wireless box III. The PC has a direct ethernet connection. The router was replaced by O2 when the problem first appeared, as the Wireless box II was suspect. However, I still have the problem and it is getting more frequent.
The symptoms are these: I generally shut down the PC each night, and only fire it up again when needed, which is usually the following evening, but it remains on for most of the day at the weekend. Very often when started, I find I have no connectivity to the internet, and cannot retrieve my emails. Strangely though, the Skype connection is still present and works, although not every time. My wife's laptop is connected over the wireless link - and that STILL WORKS! Sometimes I can connect to the router interface, but sometimes I can't. I've never lost the connection while the PC is running.
I have tried everything I can find in the router (when I can connect) and also in the Systemreferences:Network Connections and also in System:Administration:Network Tools, but can't find anything that helps. A re-boot of the PC doesn't help. A re-boot of the router doesn't help. A hard reset of the router on it's own doesn't help. The only solution to restore the connection is a hard reset of the router (using the recessed reset switch in the back) followed by a re-boot of the PC.
Since the Skype service remains working, and the lights on the router remain normal and wireless service doesn't fail, I think this has to be a DNS server problem. In the previous release, Jaunty, I changed the DNS service to OpenDNS within Ubuntu, overriding the router's settings. That seemed to help a great deal, although there was still the occasional outage which might have been another cause. I can't find anything in the GUI interface in Karmic that will let me do this, and I can't now remember how I did that in Jaunty.
I did a clean install of 10.10 just under a week ago and something is really wrong with my wired connection. I keep loosing all connectivity and have to connect again from the panel app. After that, every thing works again for about 30 to 60 seconds and the the connection goes again. No lost connection notification pop up or anything like that, but i cannot browse the web or download upgrades while the connection is gone.
Then the really weird part. Sometimes my connection works just fine. On some boots everything is fine for a long time (hours?) but then the problem comes back. My network card is an Intel 82567LF-2 and it uses the e1000e kernel module. I dual boot to Windows Server 2008 R2 and there I have full connectivity all the time.
Since I installed Ubuntu I've had this problem that makes me loose connection to the Internet. The wireless-icon on the panel starts loading, and after like 5 minutes, it works again.I had this problem when I had Mint 11, but it happened more often.Anyone know how to fix? Edit:Network: Card-1 Atheros AR9285 Wireless Network Adapter (PCI-Express) driver ath9k Card-2 Marvell 88E8040 PCI-E Fast Ethernet Controller driver sky2
Sorry if this has already been solved;answered anywhere else - I tried looking it up but to no avail. The problem persists & the hints I found around the forum did not provide a solution to the case, neither other net solutions i looked up I run Winblows at the lab and sometimes take my Ubuntu PC with me. There is an open Wireless network where they set MAC permission, and there's no pwd to access. It so should be fairly easy to change m MAC and access it, right! No. I run ifconfig and macchange, successfully change my MAC addr BUT the connection drops! Then if I change it back (MAC to my original address) it goes back online. And yes, I shut down the service -- "ifconfig wlan0 down" and then up..WHAT ON EARTH am I doing wrong??? No webpages touch this 'trouble-frigging-shooting instance!
Running 2.6.29-gentoo-r1 on a Sun Ultrasparc 10 with a Sun Happy Meal on eth0 connected directly to my cable modem. Intermittently, with a frequency between a few hours and a few days, I lose internet connectivity. Running ifconfig eth0 indicates all is well and I have a valid IP address but I cannot even ping the cable modem's management address; pings to 127.0.0.1 and eth0's IP address do get a reply but no other address I've tried does. I can 'fix' the problem by issuing
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If I check the CM logs, it appears that it has rebooted itself prior to the loss of connectivity. The strange thing is that the incoming traffic doesn't seem to be affected by this, my PSAD log is full of incoming scans even during the periods when I can't connect to the net. I suspect this is an ISP problem (they own the CM);
I'm setting up a computer with xUbuntu installed and wan't to run it as a PPtP VPN server.
I'm using a mobile broadband for internet connection, with DynDNS wich updates the host with public IP-address.
I've managed to set up the connections and installed the needed packages. The problem appears when I connect to the VPN server through another computer;
When I get connected to the VPN server the remote computer recieves an IP-address from the server (xUbuntu) wich is great! But the server changes prefered network, from the mobile broadband to the wired network wich results in the remote computer losing it's connection to the server.
I'm sure this is possible... I'm just not sure how. Yet! I have three machines. One is at home behind my firewall and has a dynamic IP. That's fine as I don't really want to open any ports on my home firewall. The second is at work sitting behind the firewall there- and I'm not even going to ask for approval to NAT an IP to my PC at work :-).
The third is in a data center far away. I only have a shell account on this server but other than that shell account not being root, I can do most anything I like with that account. What I would like to do is SSH to this server simultaneously from my home and work PCs and, via this third machine, make them talk.
This is pure geekery so it doesn't matter what they say to each other; I just want to make them talk. Maybe one uploads a file and the other just pulls down that file. Maybe one opens a FIFO on the remote server and starts writing to it while the other starts snarfing that data. In fact, I like this latter idea best, I think. How would you do it? What scripts (fired by cron if need be since I'm ostensibly away from at least one of the PCs at any given time) would you use?
lost my internet connection on fedora 12 ? i try to assaing the ip address manual in the configruation part but no nothing happen I've tried googling for the problem
can one ethernet card support multiple ip address? but i think it's very dangerous. if bad guy take many ip, other people can't get ip. "does one ethernet card take multiple real ip or multiple virtual ip(one real ip)?" if it takes multiple real ip, then how it works good?..
how to use a ethernet conenction(Marvell Yukon 88E8039 PCI-E Fast Ethernet Controller )in ubuntu...my internet requires user name and password ..can u even tell me how to config the user name and password
I installed 10.04 today, and I can't get any connection through the LAN. I've tried some stuff on my own, but I've been unsuccessful so far. It's not a hardware or connection issue, as it works perfectly fine in Windows 7. I haven't had this issue in any previous version of Ubuntu (or any Linux distro for that matter).The weirdest part is I booted from the installation CD as as LiveCD, and everything worked perfectly fine. It only stops working after I actually install it. Here's the results of ifconfig:
eth0 Link encap:Ethernet HWaddr 00:17:31:d8:d5:76 inet6 addr: fe80::217:31ff:fed8:d576/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
My ISP finished some 'upgrades' on its infrastructure. The result is that I am having great difficulty in connecting to the internet.
I have 3 operating systems on my box - XP, Fedora 8 and Feota 12.
I connect using an ethernet card, using dhcp. In fedora 12, the ethernet card is controlled be networkmanager. After the ISP completed their upgrades, I was not able to connect. I tried to connect manually using
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There was an error message -
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I read the advice here: [url], and removed all but the important lines.
But even after that neither ifup eth0 or dhclient eth0 works.
In fedora 8, the ethernet card is activated by ifup eth0 in /etc/rc.local. I was able to connect on a couple of occasions, but that too stopped working. I tried both ifup eth0, dhclient eth0, and tried to use the gui( which fires the dhclient command), but none worked.
When I use windows, it takes about 2 minutes to get an ip (earlier it was immediate). Sometimes that doesnt work and I have to click on "repair" whereupon it starts working.
Tell me how to configure my Ethernet card to work. My pc only works wirelessly. I don't know what kind of Ethernet card is installed. I have Ubuntu 10.4 on a dell pc 1ghz, 20ghd, 512mb.
i did configure as it was advised on [URL]... but it didn't work. for eg I added eth0:1 and eth0:2 on /etc/sysconfig/network-scripts/ when i do ifconfig i can see only eth0:1, i cannot see eth0:2, eventhough i configured as it was on the tutorial
I am basically wanting to use my Ubuntu 10.10 computer as a router. Note: Before you say just get a router please note that I am poor/cheap. I have two ethernet connections and one wireless connection on my netbook. I want to share the internet connection that is going into one of the ethernet cards through the other ethernet card and the wireless card.
DSL-->1sr Eth --> 2nd Eth (currently works) DSL-->1sr Eth --> Wireless Card (Adhoc) <--(connects with limited connectivity AKA no internet)
The 2nd Ethernet card already has working internet, but when I connect to the Wireless card (through an Adhoc network), it cannot get an IP (I believe).
i shut down my ubuntu karmic for a bit. turned it back on after an hour or so and now i have no network connection. i checked all the obvious things like cords etc wife's computer is connected through the same router / modem and no probs here.i even replaced the card in mine.
I just upgraded to 10.04. I had wireless connection for 1 day and now nothing. No ethernet connection either. I CAN use both wireless and ethernet using my machine on Windows.....so the connection stuff does work. Here's the output of of the commands I got from the "sticky". I can't display the output as this forum puts it all together as one continuous sentence with no line break!
When I start my Ubuntu machine, it says "eth0 connection established". But i could not able to ping to other machines available in LAN & also to Internet.
My program is working. However, I would like to add in some features. Let see my code first
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if (returnresult<=0) { printf("Connecting.... ");
[code]....
When the ethernet network connected, it will go into the else loop at line no. 13. The system will send status and display the status at control panel screen. If at this point, the ethernet disconnected, it will go back to the if loop at line 1. The system will keep trying to connect to the network and keep loop the if loop until it is connected.
Question now is I need the system to test the connection too after going into the operation loop that is start from the line no. 47. If the system went into the for (int c=0;c<cCOL;c++), it will need to do all the operations as indicated by cCOL times before it exit that loop and go into the previous loop.
I need the system to detect connection everytime an operation is going to happen or ended and if there is no connection, it will trying to connect. Before it is connected, it will not continue the operations. I tried to put the function "Connect (szPort, szAddress)" into each loop. Yes, the operation stop everytime the network disconnected. However, it shows on control panel screen "New Connection...." everytime it execute the statement. In fact, the network never disconnected.
I tried to look at the Connect function code, it is as below, I cannot figure out any statement that can stop the appearance of that "New Connection...". It may be hidden at the library source code, it is too hard for a beginner to modify the library code.
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int Connect (char *szPort, char *szAddress) { /* Set the remote port */ int port; /* port number */
