Ping and LAN Problem

[das দাশ]

On Tue, 2007-08-14 at 11:20 -0700, NoOp wrote:
> > Can you post the outout of:
> > 
> > sudo iptables -L OUTBOUND
> > sudo iptables -L INPUT
> > sudo iptables -L OUTPUT
> > 
> > Also, a suggestion: you might want to change eth0 to something other
> > than 192.168.0.1 - 192.168.0.1 typically is used for many DSL
> routers as
> > their default. Yours may be different of course, but perhaps putting
> it
> > on 192.168.1.x might help.
> 
> Also, I completely missed that you are using ipmasq as your firewall.
> Perhaps you can check the icmp rules on that?
> 
> Resources that might help:
> http://www.ecst.csuchico.edu/~dranch/LINUX/ipmasq/c-html/
> 

Dear NoOp

Here is the output, one by one:

<<<
root at mahammad:/home/dd# iptables -L OUTBOUND
iptables: No chain/target/match by that name
root at mahammad:/home/dd# iptables -L INPUT
Chain INPUT (policy DROP)
target     prot opt source               destination         
ACCEPT     0    --  anywhere             anywhere            
LOG        0    --  127.0.0.0/8          anywhere            LOG level
warning 
DROP       0    --  127.0.0.0/8          anywhere            
ACCEPT     0    --  anywhere             255.255.255.255     
ACCEPT     0    --  192.168.0.0/24       anywhere            
ACCEPT    !tcp  --  anywhere             BASE-ADDRESS.MCAST.NET/4 
LOG        0    --  192.168.0.0/24       anywhere            LOG level
warning 
DROP       0    --  192.168.0.0/24       anywhere            
ACCEPT     0    --  anywhere             255.255.255.255     
ACCEPT     0    --  anywhere             mahammad            
ACCEPT     0    --  anywhere             192.168.1.255       
DROP       0    --  anywhere             ALL-SYSTEMS.MCAST.NET 
LOG        0    --  anywhere             anywhere            LOG level
warning 
DROP       0    --  anywhere             anywhere            
root at mahammad:/home/dd# iptables -L OUTPUT
Chain OUTPUT (policy DROP)
target     prot opt source               destination         
ACCEPT     0    --  anywhere             anywhere            
ACCEPT     0    --  anywhere             255.255.255.255     
ACCEPT     0    --  anywhere             192.168.0.0/24      
ACCEPT    !tcp  --  anywhere             BASE-ADDRESS.MCAST.NET/4 
LOG        0    --  anywhere             192.168.0.0/24      LOG level
warning 
DROP       0    --  anywhere             192.168.0.0/24      
ACCEPT     0    --  anywhere             255.255.255.255     
ACCEPT     0    --  mahammad             anywhere            
ACCEPT     0    --  192.168.1.255        anywhere            
DROP       0    --  anywhere             ALL-SYSTEMS.MCAST.NET 
LOG        0    --  anywhere             anywhere            LOG level
warning 
DROP       0    --  anywhere             anywhere     
>>>

And see, this firewall is something that was done by the OS
automatically, maybe because I am using ipmasq. I never did anything
about ip-tables. I know absolutely nothing about networking. What I did
was what you can call horse's doings. I read from the router-howto that
I have to fix the router ip as 192.168.1.1, and the router connecting
LAN card's ip as something over 192.168.1.30, and hence I fixed it as
192.168.1.40, then made the 192.168.1.1 as the gateway for this eth2,
with adding this 192.168.1.1 in the /etc/resolv.conf. Then for
connecting with my laptop, I fixed the laptop's LAN as 192.168.0.2, and
the laptop connecting LAN of the desktop as 192.168.0.1. Then added this
192.168.0.1 in the resolv.conf of the laptop and made the gateway for
the laptop as 192.168.0.1, setting 255.255.255.0 as the netmask for both
of them. I did not supply the broadcast, like once I had to do in
gentoo. This was fixed by Ubuntu itself. And then I installed ssh on
both the machines, and ipmasq on the desktop such that it can supply the
ip-s to the laptop. And everything is working as expected, without ever
understanding what is happening where. Ubuntu is simpler in that sense,
when I used SuSE I had to run a squid on the desktop to do it. Now,
ipmasq is doing that. But, here is the problem, with becoming simpler
maybe it has become a bit non-transparent. Like the broadcast thing, and
the netmask reported by the machine. Who knows how it is working?

I think I must try to become a bit networking-literate. I started
reading Kirch. But it was taking so much time. After all my works and
engagements, being a teacher and writer by profession, it is a bit
difficult for me. I will read the netmasq howto that you have sent the
link. Can you suggest me one or two simple documents like that that will
help me in understanding how the network things operate in Ubuntu? 

Thank you NoOp for all the trouble you are taking. 
---
das