linux-kernel - Re: Why a host not ping-able?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1354620894.27682.5@driftwood>
Date:	Tue, 04 Dec 2012 05:34:54 -0600
From:	Rob Landley <rob@...dley.net>
To:	Woody Wu <narkewoody@...il.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Why a host not ping-able?

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--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/