PROBLEM: /proc/sys/net/ipv4/ip_dynaddr does not work correctly

PROBLEM: /proc/sys/net/ipv4/ip_dynaddr does not work correctly

[Michael Schlenstedt]

Hello!


[1.] One line summary of the problem:

/proc/sys/net/ipv4/ip_dynaddr does not work correctly in debug-mode.


[2.] Full description of the problem/report:

I've recognized that the debug-mode ("2") with
/proc/sys/net/ipv4/ip_dynaddr does not work correctly. In fact, if I do
a "echo 2 > /proc/sys/net/ipv4/ip_dynaddr", nothing happens. There are no
messages in the syslog, and there is no function of ip_dynaddr at all.

If I use "echo 1 > /proc/sys/net/ipv4/ip_dynaddr", it works fine, of
course without any debugging messages.

So it seems that the "2"-mode (debug output) does not work correctly
with newer kernels (tested with 2.4.21 and 2.4.24)


[3.] Keywords (i.e., modules, networking, kernel):

network, NAT, masquerading, dynamic ip


[4.] Kernel version (from /proc/version):

Linux version 2.4.24 (root@gandalf) (gcc version 2.95.4 20011002 (Debian
prerelease)) #3 SMP Sun Feb 15 10:43:15 CET 2004


[7.] Environment
[7.1.] Software (add the output of the ver_linux script here)

Linux gandalf 2.4.24 #3 SMP Sun Feb 15 10:43:15 CET 2004 i686 unknown
 
Gnu C                  2.95.4
Gnu make               3.79.1
util-linux             2.11n
mount                  2.11n
modutils               2.4.15
e2fsprogs              1.27
PPP                    2.4.1
isdn4k-utils           3.1pre4
Linux C Library        2.3.1
Dynamic linker (ldd)   2.3.1
Procps                 2.0.7
Net-tools              1.60
Console-tools          0.2.3
Sh-utils               2.0.11
Modules Loaded         ppp_deflate zlib_deflate bsd_comp ppp_synctty
nfsd parport_pc lp parport ipt_multiport ipt_LOG ipt_limit ipt_unclean
iptable_mangle iptable_filter ipt_MASQUERADE ipt_REJECT iptable_nat
ipt_state ip_conntrack_ftp ip_conntrack ip_tables ppp_generic slhc fcpci
capi capifs kernelcapi capiutil printer uhci usbcore apm dmfe


[7.3.] Module information (from /proc/modules):

ppp_deflate             3008   0 (autoclean)
zlib_deflate           18048   0 (autoclean) [ppp_deflate]
bsd_comp                4032   0 (autoclean)
ppp_synctty             5760   0 (autoclean)
nfsd                   45920   4 (autoclean)
parport_pc             25320   1 (autoclean)
lp                      6528   0 (autoclean)
parport                24704   1 (autoclean) [parport_pc lp]
ipt_multiport            640   8 (autoclean)
ipt_LOG                 3360   8 (autoclean)
ipt_limit               1056   9 (autoclean)
ipt_unclean             6784   1 (autoclean)
iptable_mangle          2208   0 (autoclean) (unused)
iptable_filter          1760   1 (autoclean)
ipt_MASQUERADE          1504   0 (unused)
ipt_REJECT              3264  18
iptable_nat            16596   1 [ipt_MASQUERADE]
ipt_state                608  20
ip_conntrack_ftp        3936   0 (unused)
ip_conntrack           21428   3 [ipt_MASQUERADE iptable_nat ipt_state
ip_conntrack_ftp]
ip_tables              12032  12 [ipt_multiport ipt_LOG ipt_limit
ipt_unclean iptable_mangle iptable_filter ipt_MASQUERADE ipt_REJECT
iptable_nat ipt_state]
ppp_generic            23308   1 (autoclean) [ppp_deflate bsd_comp
ppp_synctty]
slhc                    4736   0 (autoclean) [ppp_generic]
fcpci                 531008   3
capi                   19360   8
capifs                  3584   1 [capi]
kernelcapi             30880   4 [fcpci capi]
capiutil               22464   0 [kernelcapi]
printer                 7776   0
uhci                   25320   0 (unused)
usbcore                60256   1 [printer uhci]
apm                     9692   0 (unused)
dmfe                   12348   1


Bye,
Michael

Re: PROBLEM: /proc/sys/net/ipv4/ip_dynaddr does not work correctly

[David S. Miller]

On Sun, 15 Feb 2004 22:22:42 +0100
Michael Schlenstedt <Michael-ml-kernel@schlenn.net> wrote:

> 
> [2.] Full description of the problem/report:
> 
> I've recognized that the debug-mode ("2") with
> /proc/sys/net/ipv4/ip_dynaddr does not work correctly. In fact, if I do
> a "echo 2 > /proc/sys/net/ipv4/ip_dynaddr", nothing happens. There are no
> messages in the syslog, and there is no function of ip_dynaddr at all.

It will only print a "debugging message" if the IP address of the system
changes and a packet is attempted to be sent over a TCP connection, then
it will print a message looking like:

tcp_v4_rebuild_header(): shifting iner->saddr from x.x.x.x to y.y.y.y

And it in fact does do this.

Re: PROBLEM: /proc/sys/net/ipv4/ip_dynaddr does not work correctly

[Michael Schlenstedt]

David S. Miller sagte:

> It will only print a "debugging message" if the IP address of the system
> changes and a packet is attempted to be sent over a TCP connection, then
> it will print a message looking like:
>
> tcp_v4_rebuild_header(): shifting iner->saddr from x.x.x.x to y.y.y.y
>
> And it in fact does do this.

Well, it doesn't in my configuration. In fact, there is no function of
dyn_ipaddr at all in my system (even if I use a "echo 1 > ...").

Maybe this is an issue of the combination of pppd and the capi-plugin? I
can remember that I haven't had any problems with pppd and pppoe (and an
early kernel-revision).

Bye,
Michael



-- 
      ___                     Michael@schlenn.net         o
     /_\ `*     `  _ ,  http://www.schlenn.net/~michael  /_\ '         ,,,
    (o o)      -  (o)o)      ICQ: 38605983 (Schlenn)    (o o) -       (o o)
ooO--(_)--Ooo--ooO'(_)--Ooo-------------------------ooO--(_)--Ooo-ooO--(_)--Ooo-