8 Apr
2009
8 Apr
'09
1:05 p.m.
Dear All,
I have a ADSL broadband connection of BSNL. The ADSL modem is connected to
our Internet Server (Fedora box) to one of the NIC card(eth1), the other
NIC card (eth0) is connected to our LAN switch. This Fedora box acts as
the gateway machine to the Internet for our LAN.
The Problem:
------------
The LAN users were not getting the Internet. I saw the PPP link was up
and running on the Server and also the Modem link was ok., but I couldn't
ping to their (ISP's) end. (Destination port unreachable message was
coming).
I called the ISP and after a while, the LAN users were able to get the
Internet but during the same time, I was not able to ping to their gateway
and also to their DNS IP from my Internet Server.
Then when i restarted my iptables script file, i was able to ping ISP's
gateway and their DNS IP too.
I just want to know, when my LAN users were getting the Internet, Why I
couldn't get the reply from either their (ISP's) gateway / their DNS IP.
Hope someone might be able to explain me what the problem could be.
Thanks in Advance,
Regards,
George
8 Apr
8 Apr
9:12 p.m.
On Wed, Apr 8, 2009 at 1:05 PM, <george(a)annamsoft.com> wrote:
Hope someone might be able to explain me what the
problem could be.
Providing more information on the setup and what you have done will be
very useful.
You could start with the output of these commands
ifconfig eth0
ifconfig eth1
cat /proc/sys/net/ipv4/ip_forward
--
If you think nobody cares if you're alive, try missing a couple of car
payments. -- Earl Wilson
21 Apr
21 Apr
10:22 a.m.
Dear All,
The ISP guys called up and said some port was changed at their end and
hence the problem, but i would like to know once there was no gateway
route/path on the Internet Server, how come the LAN users were able to
browse from their workstation after the port was changed at the BSNL end
before me running the firewall Script which starts the adsl connection and
assigns IP to the ppp0 interface, this boggles my mind.
During that time when this problem occurred, following was observed on the
Internet Server:
ifconfig eth1 had its IP set OK (i.e our internal LAN IP)
ifconfig ppp0 had NO IP assigned (Public IP-Dynamic) since as BSNL said
they were changing some port at their end.
IP forwarding was OK.
Regards,
George John
On Wed, Apr 8, 2009 at 1:05 PM,
<george(a)annamsoft.com> wrote:
Hope someone might be able to explain me what the
problem could be.
Providing more information on the setup and what you have done will be
very useful.
You could start with the output of these commands
ifconfig eth0
ifconfig eth1
cat /proc/sys/net/ipv4/ip_forward
--
If you think nobody cares if you're alive, try missing a couple of car
payments. -- Earl Wilson
--
http://mm.glug-bom.org/mailman/listinfo/linuxers
22 Apr
22 Apr
9:24 p.m.
george(a)annamsoft.com wrote:
The ISP guys called up and said some port was changed at their end and
hence the problem, but i would like to know once there was no gateway
route/path on the Internet Server, how come the LAN users were able to
browse from their workstation after the port was changed at the BSNL end
before me running the firewall Script which starts the adsl connection and
assigns IP to the ppp0 interface, this boggles my mind.
During that time when this problem occurred, following was observed on the
Internet Server:
ifconfig eth1 had its IP set OK (i.e our internal LAN IP)
ifconfig ppp0 had NO IP assigned (Public IP-Dynamic) since as BSNL said
they were changing some port at their end.
IP forwarding was OK.
Since there is no black magic involved ;-) , it is most likely that a
route was available which went un-noticed. Sometimes with cable internet
which uses no dhcp and only pppoe, it so happens that dhcp does work
sometimes and even allows browsing without pppoe. I have noticed this
with new installations or after replacement of ethernet cards. However
after the new mac id is locked at the cablenet provider end, there is no
dhcp and net access is only through pppoe. Those familiar with setup of
pppoe Servers may be able to shed more light on this phenomenon.
--
Regards,
Rony.
GNU/Linux !
No Viruses
No Spyware
Only Freedom.
5154
days inactive
5168
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3 comments
3 participants
participants (3)
-
george＠annamsoft.com -
Mehul Ved -
Rony