I'm trying to troubleshoot some networking issues I'm having between my Linux servers connecting to a server at another location after a Cisco ASA firewall has been installed at my location. I can make the connection work if I lower the mtu on the NIC (ifconfig eth0 mth 1000) - however that supposedly can break the local network if I don't set everything else's mtu to match. Supposedly I can use the iproute package (debian etch) to lower the mtu on a per-route basis, but it doesn't seem to work for me.
Code:
ip route delete default
ip route add default via X.X.X.X mtu 1000
I use my computer as a gateway to the internet for the rest of the house which is split into two LANs. I also have VPN's linking the office side of the LAN to a remote site. All of the PC's other than mine that should have access to the VPN works, but my PC doesnt and I firmly believe this is because I need to add a static route. ping 192.168.10.1 doesnt work but ping -I eth2 192.168.10.1 does. 192.168.10.1 is the remote router on the other side of the VPN. I've tried this route:
Code: route add -net 192.168.10.0 netmask 255.255.255.0 gw 192.168.1.1 dev eth2 192.168.1.1 is my computer... the gateway for the rest of the house/office. My computer has a quad NIC, only 3 ports are used. WAN, LAN1 and LAN2. Aside from this routing issue, I have everything working perfectly.
I have recently set up two machines with F14 and on both, I am completely unable to make remote login via SSH work. openssh-server is installed and seems to work well:
I have already worked for hours on the problem now, using Google and trying numerous things, and still could not find any solution. On my other machine, which still uses F13, remote login works just fine. Is there any change in the default behaviour of the sshd I am not aware of? I would really appreciate your assistance!
br0 - 192.168.0.1 - Internet eth2 - 192.168.1.1 - LAN tun0 - 10.0.0.2 - VPN (via br0)
What I'd like to do is to route all TCP packets coming from eth2 to tun0 where a VPN client is running on 10.0.0.2. If I delete all default routes and if I add a new route to tun0 like :
Code:
route del default route add default gw 10.0.0.2
Everything is fine, and everyone on eth2 can reach the Internet using the VPN access. Now the problem is that my VPN client does not allow any other protocols other than TCP. And I also want to allow VPN access only to eth2, no other LAN nor the router itself. use iptables to filter any TCP packets and mark them, so they can be sent to tun0, while any other packets can reach the Internet via br0 (192.168.0.1). I found on the Internet that we can mark packets before they get routed. Using the following commands :
Code:
iptables -t mangle -A PREROUTING -j MARK --set-mark 85 -i eth2 -p tcp --dport 80 ip route add table 300 default via 10.0.0.2 dev tun0 ip rule add fwmark 0x55 table 300
First of all, --dport 80 never work... :/ I wanted to filter TCP 80 packets coming from eth2, but none of them seems to be HTTP packets... oO (very strange...). Nevermind, I decided to forget about the --dport option. I use the "iptables -L -v -t mangle" command to see how many packets are marked, and it is working fine, all TCP packets coming from eth2 are marked. Now the problem is that none of them are routed to tun0 they are all respecting the "route -n" rules... and not the "table 300" rule I have created.
I got this definition:"a process that replaces a series of related, specific routes in a route table with a more generic route." honestly I found it not so clear.. I want to know if this definition is correct and also more details about this subject..
Having trouble getting my Netgear WNA1000 working thru wireless router. Have tried lots of suggestions from other threads to no avail. Someone suggested that th routing table isn't set correctly, so have been trying to use the follwing to make the proper entry in the routing table: sudo route add -net 192.168.0.1 netmask 255.255.255.0 dev wlan0
Result: error message stating with: "route: netmask does not match route address"
followed by "Usage" instructions which tell me to do what I just did. Any ideas on how I can populate my routing table with correct entry for my wireless card? Not to complicate matters, but I temporarily turned off encryption on my router to eliminate that as a possibility until I get connected. So maybe it'still trying to connect via encrypted mode - do I need to turn off encryption on my (client) end?
I have this annoying problem since day one.I am testing out Red Hat RHEL5, everything is fine except DNS look up.If I ping www.google.com, it doesn't work, ping ip address it all works;if I bring up browser, put www.google.com it doesn't work, can't find the name, however, simply put ip address there it works.My DNS seeting seems ok, and the DNS works from Windows box.
yesterday I installed openSUSE 11.2 on my laptop. But I'm having problem getting the wifi configured properly. During the installation I got the message "No network running" (which I also saw after the installation when using the network configuration module of YaST after switching from ifup to NetworkManager). After installation NetworkManager seemed to work fine, it detected my wifi card, found the network, and I could even connect to it. Then the problems began, no Internet connection. The first thing I tried was pinging Google which yielded an "unknown host" message. So I checked /etc/resolv.conf, to look for the DNS servers, which where missing.
I added them manually and tried again. Still no luck, so I started pinging my router, which worked, tried again pinging Google using one of there IP addresses, which failed. So I ran route to find out which routes where being used, this one gave an unexpected result, because it only showed the route to the local network (I'm not sure about the loopback one, because this was also a lot of times missing when testing):
Networking on Fedora 11 doesn't work for me on various machines. Fedora 10 does, but only if you don't do an update.Why does Fedora get worse the more you keep it up-to-date?
I have 2 guest machines on 1 VBox host installed : - one guest with hostname 'debian' is configured as follows and has IP Forwarding enabled to be able to route traffic from eht1 to eth0.
Code: eth0 Link encap:Ethernet HWaddr 08:00:27:f1:ef:5f inet addr:10.0.2.1 Bcast:10.0.2.255 Mask:255.255.255.0 inet6 addr: fe80::a00:27ff:fef1:ef5f/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
I have two simultaneous active mobile connections through my two mobile phones and USB data cables. Yet I can only send/receive with one connection.
Each of the phone modems have a node in /dev, namely ttyACM0 and ttyACM0. So the modems are detected correctly. After setting up two dial-up connections with the two modems I have two ip's. Ifconfig-a confirms this:
I'm using ubuntu 9.10 with kernel 2.6.33.I want to plot the cwnd of some tcp connections over the time.So I activate the module (as root) with:modprobe tcp_probeand after that I did:cat /proc/net/tcpprobe > test.log &And than I do a little bit surfing or other things, which use tcp - but the file test.log is empty
I have recently installed ubuntu 10.04. After some days of trying I can say that ekiga doesn't work with 10.04. With the same computer I was perfectly able to use ekiga with ubuntu 8.1, the 10.04 gives me connections problems.... it simply say says "Could not register (Failed)".I'm trying to connect with my voip provider (12voip.com) but it seems that I can't. I have even tried other programs like empathy, Twinkle, QuteCom but with none of them I can connect with my voIP provider. I think there are some connection problems but I really don't know how to face them. We have to configure router in 10.04 for sip connection? Actually I can't phone at all.
I've tried to use netcat in the past and assumed it was my stupidity that was preventing it from working... but this is getting ridiculous. I'll execute nc -l 3333 on a server at 192.168.0.105 (after opening it on the firewall of course) then I run nc 192.168.0.105 3333 on my laptop (from 192.168.0.101). and nothing happens... i start typing and nothing comes up on the terminal.
I run nc -z 192.168.0.105 80 which should ideally do a port scan of port 80 on that server (of which I'm running a web server that clearly works) but it doesnt even give me any feedback. Nothing happens. Now when I use the verbose flag i see that I am indeed connecting to the specified port on the server successfully (so the port scan one is a success but only with the verbose flag... which shouldnt be the case I believe). But still once I have the server listening and the laptop connected... I type in both windows and nothing happens...
I am networked to a Windows machine. I can see and open files across the network. I can see and add my HP 6000 printer (it is on the Windows machine). On my Ubuntu machine this printer has a check mark by "Enabled" and "shared" but I cannot set it as default (that option is ghosted) and when I try to print a test page it says "unable to connect to CIFS host" I downloaded the HP Linux setup program. That program cannot locate the networked printer at all.
I'm running Ubuntu 10.04 on my laptop. Up until about a week ago, my wireless worked fine, but now it rarely connects. Sometimes the connection indicator shows that I am connected, but when I click on it it doesn't show any active networks. Even when I use a wired connection it doesn't always work.
i have had my bluetooth keyboard and mouse working fine for a little while now, then one day.. seemingly out of the blue (no pun intended) it stopped. heres what i deduced:
Mouse works fine, always keyboard doesnt.
I'm using a logitech dinovo edge
and i can manually force the keyboard to connect by putting the keyboard into discoverable mode (press the button on the back of it) and using hidd:
Code: hidd --connect XX-XX-XX-XX-XX-XX but who the heck wants to do that on every reboot or resume from sleep! yikes.. firstly, i noticed that bluetoothd was segfaulting alot: Code: ec 22 17:26:09 hostname kernel: [21329.811149] usb 2-6.2: new full speed USB device using ohci_hcd and address 6
i've installed it on my parents old computer, mostly for downloading. But wired internet did work all the time but then i had to reset our router because of some problems and now it doesn't work anymore! But the strange thing is, if i put the cable on my own laptop with windows on it, then it works as normal.
So i guess its some kind of DNS problem, but i'm very new with ubuntu and also not so good with computers. Our network is simple just an modem connected to an router: Sitecome WL-341.
I have two simultaneous active mobile connections through my two mobile phones and USB data cables. Yet I can only send/receive with one connection.Each of the phone modems have a node in /dev, namely ttyACM0 and ttyACM0. So the modems are detected correctly.After setting up two dial-up connections with the two modems I have two ip's. Ifconfig-a confirms this:
ppp0 Link encap:Point-to-Point Protocol inet addr:10.10.219.60 P-t-P:10.6.6.6 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
my problem is following: I'm running a bridged OpenVPN on my Debian. If the service is running, everything works fine: local and Internet, ftp, mailing from in and outside etc. But, when stopping OpenVPN, sending mails from inside (LAN) fails: I cannot reach smtp (postfix) listening on port 465. And even reaching mailboxes using IMAP gets horribly slow eg. in Thunderbird. Here is my firewall.sh script.
Quote:
#!/bin/sh echo " IPTABLES FIREWALL inicializalasa - szures" # Enter the designation for the Internal Interface's INTIF="eth0"
I am trying to monitor a Centos 5.3 box using SNMP and I am having a lot of trouble getting the data that i need from it. Everytime I try to get information from the UCD-SNMP MIB it returns "End of MIB". It is my understanding that UCD-SNMP is a standard package when Net-SNMP is installed and should always be there. Then why can't I access it? I have tried removing the reinstalling Net-SNMP, but that hasn't worked. My server is update date on all it's patches as well. It is quite old hardware, but I don't believe that should affect SNMP from being gathered. Iptables is down, and I cant' even get it from the local machine.
Ok so I just installed Ubuntu 10.10 Server Edition. On the very first boot, everything seems to run perfectly. I can SSH into it from any remote computer with no problems. However, the installation of certain things calls for a system reboot, which 2 days ago never would have been a problem. But now for some reason, the SSH server only wants to work on the very first boot of a clean install. After I reboot it, I get the ssh: connect to host 192.168.0.180 port 22: No route to host error. The absurd part is sshd is running! I've even tried restarting sshd, restarting the server, and using both 64 and 32 bit installs. The only way I can get anything to connect to it is by using ssh localhost. It won't even let me connect using the IP on the local machine!
I installed F10 today. From live-usb wlan worked fine, but after installing it doesn't find any networks. I tried to google this problem, but everybody says wifi works out of the box. Not for me.
Solved: I disappled wireless networking and appled it again. It found all networks.
I have installed Fedora 12 on my laptop.Installing my Broadcom BCM 4312 wireless drivers works just fine, but after a reboot I have to reinstall them. modprobe wl, modprobe wlan0 etc doesn't work either. I need to reinstall them every time I reboot.
I'm runnig f 13 on my laptop, and it runs like a charm. But once in a while, the internet doesn't seem to work properly. It mostly works, but right now i am unable to reach certain pages such at google (which is annoying), whereas other pages like yahoo and this one works perfectly well.
how nobody else could have run into this in the meantime. [URL] Two friends of mine are having the same issue on Ubuntu-11.4-machines. In short: Connecting to the Cisco-VPN via shell-command "vpnc" works flawlessly, whereas NetworkManager just doesn't connect at all. We had this working in older versions of Fedora/Ubuntu about some months ago...
