lkml.org 
[lkml]   [1997]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: IP Masq question in pre-2.0.31-1
Date
On Mon, 14 Jul 1997 02:56:42 -0400 (EDT), 
Jon Lewis <jlewis@inorganic5.fdt.net> wrote:
>Just out of curiosity, why is the code that prints things like:
>
>MASQ: forward ICMP: failed checksum from 208.136.4.175!
>MASQ: forward ICMP: failed checksum from 151.200.189.101!
>
>outside the ifdef's for CONFIG_IP_MASQUERADE_ICMP. i.e. I don't have
>CONFIG_IP_MASQUERADE_ICMP set in this kernel though I do have
>CONFIG_IP_MASQUERADE, yet am seeing the above on a multi-ether linux
>router. Is there a good reason not obvious to me, or is it an oversight?

Standard masq has to support ICMP replies for outgoing TCP/UDP packets.
Otherwise masqed applications would not see things like "no route to
host" or "need to fragment" and would wait for a long time.
CONFIG_IP_MASQUERADE_ICMP lets masqed hosts do ping or traceroute. The
messages you are seeing are bad checksums on ICMP responses to outgoing
TCP/UDP.



\
 
 \ /
  Last update: 2005-03-22 13:39    [W:0.033 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site