Linux - NetworkingThis forum is for any issue related to networks or networking.
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Hi there! I am running a tiny home network via the TCP/IP protocol.
I have no server (yet) so I am manually assigning IP addresses to my boxes.
My Linux box is 192.168.0.2
The Windows box I want to connect to is 192.168.0.4
I get 'destination unreachable' messages when I try to ping to 192.168.0.4 from the Linux box. Pinging to 192.168.0.2 from the Windows box gets the same result.
I have another Windows box, 192.168.0.6, which the other windows box can see just fine.
I'm positive it's my linux box that's not right.
When I boot the Linux box, the messages fly by but I do see that "eth0" is initialized properly.
My Linux box config:
Abit NF7 mobo (whose integrated nforce2 NIC I am using to communicate and I downloaded and installed the newest drivers from nvidia's site)
AMD Athlon 2100+ CPU o/c'ed to 2700+
1GB RAM
WD 40GB HD
SuSE Linux 8.2 Pro using SuSE Firewall2
I don't know how to configure the firewall to accept transmissions from 192.168.0.4 or 192.168.0.6 in the internal network while blocking everything else out.
what version of windows are you using? are you running any versions of any firewall on windows? i.e. zonealarm, or microsofts one?
just a few other things to check
1. i assume that your using a hub for your network ( cat5 ? ) make sure that you get a link light on either your hub or on the linux pc, if not get your cable checked out
2. login as root, and type: ifconfig is eth0 listed and how many packets are you getting in and out? any errors? ( list the output if your unsure )
3. you mention your windows boxes cannot see your linux boxes and you cannot ping them, try pointing your windows web browser at you linux box, do you get anything? ( all this is provided that you have a web server running on the linux box )
4. login as root and check your firewall, by typing:
iptables -L
this will list the rule tables, please list the contents here and we can do through it together
I apologize for my miscommunication; the win boxes can see each other but not the linux box. The linux box cannot see the win boxes. The linux box seems to be completely isolated.
I do have the same subnet mask (255.255.255.0) for all three.
Cat 5 cable is standard.
I am a Linux newbie. I originally wanted to check the configuration for link speed to make sure it's set properly (and that could be it) but I can't find a thing and SuSE's graphical config program has nothing on this.
first i need to ask you, is this machine directly internet connected?
if not its not directly connected to your internet connection, i ( personally ) would recommend flushing your firewall script compleatly and starting from scratch
your firewall has this line in the output table:
DROP icmp -- anywhere anywhere icmp destination-unreachable
basically its dropping all icmp trafic ( Ping, traceroute ) coming from anywhere going to anywhere and give the destination unreachable error back to the program
however there are two options either my previous one ( blank the lot and reset it ( IF its not internet connected ) or we can try and pick through the current setup
to blank it you can do the following as root:
iptables -F
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
that will leave you with no firewall, caution is advised, linux questions and i are not reponsible if you machine gets broken becuase of some hacker ( sorry i have to metion it but its silly to be directly connected to the web and have no firewall )
for now i will suggest trying that, if you get a response from the pings we know its the firewall, and we can start going through it bit by bit
also looking at the out put of ifconfig i see that the card is receiving no packets, no you'v either just switched the box on or the card is broken
Yup, it's directly connected to the internet (via the 56k modem).
I did what you said and looked at the iptables config to verify those were the only instructions. Then I tried pinging back to my XP boxes. Still no go, "destination is unreachable".
I reconfigured SuSEFirewall2 before reconnecting to the 'net. So I'm back where I started.
I still think there might a problem between what the switch sees as the connection (100Mb/full duplex) and what Linux is thinking. I had a similar problem with Windows once, but I'm still more familiar with Windows... :-( But that aside, what else could be wrong?
I am tempted to put in the other ethernet adapter just to see if it works. It could possibly be the jack on the mobo that doesn't work and I've never twisted the cable to the point where it would have gone bad, though I should test it anyway.
one last thing you could try before you do the card, flush the firewall rules again and check on your XP boxes to see if you have microsofts firewall thing active if you do switch it off and then try pinging back to the windows box.
also after flushing the firewall try pinging the linux box again from a windows box, after doing that, successful or not, go to the linux box, log in as root and run ifconfig has the received and transmitted packects gone up?
also after flushing the firewall, as root type the following command:
echo 0 > /proc/sys/net/ipv4/icmp_echo_ignore_all
then try pinging again from windows, does it work or fail?
what version of XP do u run? your up sh*ts creek if you have HOME. at least thats how it played out for me about a year ago... PRO works fine but HOME wont even recognize a ping....youll find that when windows tries to ping linux, if you run a tcpdump, youll see the linux box send and ACK back but windows says it doesnt get it.....so if you have HOME edition im betting thats the problem.
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