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RE: can't ping local 'net, even with no firewall



I'm assuming you have done an

echo 1 >  /proc/sys/net/ipv4/ip_forward

to enable forwarding.

> -----Original Message-----
> From: Matthew Garman [mailto:garman@uiuc.edu]
> Sent: 22 July 2001 19:22
> To: Netfilter; Debian Firewall List
> Subject: can't ping local 'net, even with no firewall
> 
> 
> 
> I have an internal LAN with two computers.  Even with no 
> firewall, I can't
> get the two computers to ping each other.  For example, do 
> the following
> to flush all iptables:
> 
> 	iptables -F
> 	iptables -t filter -F INPUT
> 	iptables -t filter -F OUTPUT
> 	iptables -t filter -F FORWARD
> 	iptables -t nat -F
> 	iptables -t nat -F PREROUTING
> 	iptables -t nat -F POSTROUTING
> 	iptables -t nat -F OUTPUT
> 	iptables -t mangle -F
> 	iptables -t mangle -F PREROUTING
> 	iptables -t mangle -F OUTPUT
> 
> Now I set all default policies to ACCEPT:
> 
> 	iptables -P INPUT ACCEPT
> 	iptables -P OUTPUT ACCEPT
> 	iptables -P FORWARD ACCEPT
> 	iptables -t nat -P PREROUTING ACCEPT
> 	iptables -t nat -P POSTROUTING ACCEPT
> 	iptables -t nat -P OUTPUT ACCEPT
> 	iptables -t mangle -P OUTPUT ACCEPT
> 	iptables -t mangle -P PREROUTING ACCEPT
> 
> And still the two computers can't ping each other.  When I 
> try to ping, I
> watch the lights on my switch: the lights for both computers 
> are flashing,
> indicating link activity, but still ping times out.
> 
> On my computer, which has the Internet connection, I can ping 
> any host out
> on the internet.
> 
> Any thoughts?
> 
> Thanks,
> Matt
> 
> -- 
> Matt Garman, garman@uiuc.edu
> "I'll tip my hat to the new constitution, Take a bow for the 
> new revolution
>  Smile and grin at the change all around, Pick up my guitar and play
>  Just like yesterday, Then I'll get on my knees and pray..."
>             -- Pete Townshend/The Who, "Won't Get Fooled Again"
> 
> 



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