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Old 09-16-2004, 10:28 AM   #1
mystique98ls
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Registered: Sep 2004
Distribution: RedHat 6.2
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ipchains ? Unable to access internet ... dns error !


Hi,

I am not able to access internet using netscape from a linux machine which is on LAN network. I made the required changes in the file: resolv.conf. I guess its the ipchains firewall setup that is prohibiting me from accessing internet. Can anyone please tell me how to set up the input and output rules of ipchains? Also, is input option rule used at all when I try to access internet. Please suggest. Thanks.
 
Old 09-16-2004, 12:10 PM   #2
qwijibow
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the input rule applys to all imcomming data,
please post a copy of your firewall fules.

also... is your LAN running a DHCP server ?
if soyou shoudnt need to edit the resolv.conf file !

if not running hdcp servers, amke sure you set the gateway IP correctly.
 
Old 09-16-2004, 12:27 PM   #3
orgcandman
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neither input nor output rules are used. forward rules are used instead (iirc). You should check a few things:

1. your router can route packets between interfaces

2. your router is specified as the default gateway for the machines in question

3. the machines in question are actually connected to the lan (don't laugh...it's happened)

4. the machines in question don't have any packet rules on them that would modify the packet before it goes on the wire

5. your router and machines are on the same IP segment

6. your machines can ping or otherwise contact your router and vice-versa.
 
Old 09-16-2004, 01:25 PM   #4
mystique98ls
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OK... The ipchains rules are as follows:

Chain input (policy ACCEPT):
target prot opt source destination ports
REJECT tcp ------ anywhere anywhere any -> 6013
REJECT udp ------ anywhere anywhere any -> 1027
REJECT tcp ------ anywhere anywhere any -> 5064
REJECT udp ------ anywhere anywhere any -> 33615
ACCEPT all ------ anywhere anywhere n/a
Chain forward (policy ACCEPT):
Chain output (policy ACCEPT):
target prot opt source destination ports
ACCEPT all ------ anywhere anywhere n/a

The machine is connected to internet. The server is not DHCP. The same network connection works for my WinXp machine.
I cannot ping to anyother machine except for the ones on the LAN. I was just once able to connect to the internet when I deleted one of the output policies. which would reject all outgoing data packets. After rebooting the machine, I lost access to internet.

Still help needed...
 
Old 09-16-2004, 07:47 PM   #5
qwijibow
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So.... there is No DHCP.. this means that YU must set everything manually.... you have setup the DNS server file, good.
now you must set the gateway IP ?

what is the IP of your gateway ?
and have you set the gateway ip correctly !

im 99% sure this is a gateway IP not being set correctly.

as for the firewall !!!
who wrote that !
its the worst firewall ever. its almost completely pointless !
 
Old 09-17-2004, 09:06 AM   #6
mystique98ls
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Registered: Sep 2004
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I think the gateway is specified correctly. When I issue the command route -n; it shows the correct gateway. Though I dont know how to specify the gateway. Well, I am able to access the internet now after a reboot. Thanks for your suggestions.
 
  


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