Re: Why a host not ping-able?

From: Rob Landley
Date: Tue Dec 04 2012 - 06:34:47 EST

On 12/04/2012 12:17:25 AM, Woody Wu wrote:
Hi, list

I am not sure this has something with kernel.

It doesn't.

But the system I just
generated cannot be reached from ping. It can ping outside, but if I
ping it from outside, I just get "Destination Host Unreachable".

Some distributions' default firewall rules respond to icmp packets with a host unreachable packet. This is a system/network administration thing (iptables) and nothing to do with kernel development.

I think there is not firewall in between,

There's a firewall built into linux, read the man page for the "iptables" command. The "iptables-save" command dumps your entire current ruleset to stdout so you can see what's in there. (You might have to run it as root, I forget.)

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