Hello,
I am having some problems with making iptables work. I have
a standard Slackware 9.0 installation, which is running kernel
2.4.22.
My problem is this, it seems like no matter what iptables
commands i issue, the kernel ignores them and acts as if
i never issued them.
To start with, i would just like to be able to DNAT all connections
from one port to another port, all on the same computer over the
local loopback.
The command i have been using is:
iptables -t nat -A PREROUTING -p tcp -j DNAT --dport 4444 --to-destination
127.0.0.1:23
but I have also tried many variants of this, including trying to use the
REDIRECT option to make all connections go to one port, but to no
avail.
My method of testing if it has worked or not is thus: Since i am trying
to redirect from port 4444 to the telnet port, i try to telnet to port 4444
hoping (maybe wrongly...) that i would get the telnet service.
After this attempt, i also tried the kernel version 2.4.26 with all the
iptables options compiled directly into the kernel. I noticed there that
there was one mentioning support for NAT on the local loopback, so
I compiled that one into the kernel as well. But still, I have the same
results.
If anyone could help me with this, i would be greatly appreciative.
Craig.
Follows is attached some information from various sources on my
computer which should be of help in finding the problem...
output from "iptables -L"
Chain INPUT (policy ACCEPT)
target prot opt source destination
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
output from "iptables -L -t nat"
Chain PREROUTING (policy ACCEPT)
target prot opt source destination
DNAT tcp -- anywhere anywhere tcp dpt:krb524
to:127.0.0.1:23
Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
loopback * 255.0.0.0 U 0 0 0 lo
output from "ifconfig"
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:189 errors:0 dropped:0 overruns:0 frame:0
TX packets:189 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11227 (10.9 Kb) TX bytes:11227 (10.9 Kb)
modules loaded:
arp_tables 9132 0 (unused)
iptable_filter 1644 0 (autoclean) (unused)
iptable_nat 15928 1 (autoclean)
ip_conntrack 18120 1 (autoclean) [iptable_nat]
ip_tables 12288 4 [iptable_filter iptable_nat]
snd-pcm-oss 37252 0 (unused)
snd-mixer-oss 11992 0 [snd-pcm-oss]
printer 7040 0 (unused)
parport_pc 14724 0
parport 23264 0 [parport_pc]
uhci 24496 0 (unused)
usbcore 58400 1 [printer uhci]
snd-via82xx 11712 0
snd-pcm 55904 0 [snd-pcm-oss snd-via82xx]
snd-timer 13252 0 [snd-pcm]
snd-ac97-codec 37240 0 [snd-via82xx]
snd-page-alloc 6004 0 [snd-via82xx snd-pcm]
snd-mpu401-uart 3136 0 [snd-via82xx]
snd-rawmidi 12512 0 [snd-mpu401-uart]
snd-seq-device 3920 0 [snd-rawmidi]
snd 27460 0 [snd-pcm-oss snd-mixer-oss snd-via82xx
snd-pcm snd-timer snd-ac97-codec snd-mpu401-uart snd-rawmidi snd-seq-device]
soundcore 3332 3 [snd]
ide-scsi 9424 0
agpgart 39576 0 (unused)
