Messages in this thread | | | Date | Tue, 04 Dec 2012 05:34:54 -0600 | From | Rob Landley <> | Subject | Re: Why a host not ping-able? |
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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.)
https://help.ubuntu.com/community/IptablesHowTo
Rob
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