Linux - NetworkingThis forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.
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i have been trying to use traceroute. When i type it in i get 1.*** to 30. ***. So I looked in iptables -L and it says that my icmp port is unreachable. Think that this is my problem but not sure how to fix it. It looks like the file iptables is a binary file so not sure how to edit it?
From what i know of iptables is that it is a set of rules to use for network activity.
I have problem launching traceroute .. I have it instaled but the terminal reports it as a unrecognized command .. I'm running KDE .. any idea what I can do ?
Thanks ..
Oh .. another thing .. is there anyway I can view the computers on the LAN grouped by Workgroup .. something like the "Network Neighbourhood" thing on Windows ? And is there a way to see the machines by name and not by their IP address ?
Last edited by darkknight_9; 12-22-2002 at 09:05 PM.
rohang
I have a new install of rh8.0. unless a fire wall was installed by default one is not installled. And if it is have no idea how to shut it off to test.
i dual boot with windows i can switch to window and run traceroute just fine thought it might be the router stoping it.
Yah.. RH will install iptables in 'medium' mode by default.
Sounds like you've got yourself a script there.
You can disable it by :
1) at a prompt type setup
2) select Firewall Configuration
3) Select No Firewall
4) traceroute something
Once you've established that it's running you might want to look closer at your icmp settings. I'm not sure that the default iptables setup looks like, but I expect it'll be filtering icmps in, but contain settings for icmp originating from your side - letting them in.
Many scripts filter based on ip address aswell, common ones include the private ip subnets of
10.x.x.x
192.168.x.x
Now, you *shouldnt* be expecting incoming from those ip's because they *shouldn't* be routing across the internet. However, many cable companies for instance, use the 10.x subet for their cable modems (the actual modem) and if you block *everything* from 10.x addresses, and 192.168.x.x addresses then your cable modem won't talk to you.
So, unblock those, and ensure it still works, and then if you're paranoid, put back blocks for services you don't want.
I did as you suggested and turned off the firewall. Still get the 1.*** 2.*** and so on when i run traceroute? Bout to pull my hair out on this one. I did a iptables -L and there is a message that says the icmp port is unreachable. I got to figure that somewhere there is somthing blocking traceroute.
Guess i'll look for a iptables & ipchains howto and see if i can find any information about this. Any thing eles that i might try would be appreciated.
which will flush your table rules. It won't flush any tables created which aren't standard tables though, but they'll be hanging off those above, so that should sort you out.
Reading about this is definately encouraged, and if you find where your iptables script is running, posting the script would also be useful.
i tried the iptables -F INPUt and that did not work. Sending what this looks like in the hope it may help. It seems that it should work but something is still blocking it or will not send a icmp packet.
Well someone else told me to try traceroute -I. That works with the firewall on or off. The -I switch forces the use of icmp packets. Traceroute without the -I switch will use udp packets. Ping I think also uses icmp packets?
It works ok but not sure why. Need to do some reading to figure it out.
Anyone that knows what How to's to read or what area to look in let me know.
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