RH8: Internet packets refused, why?

Dear all,

I am facing a strange problem; I am sure that the reason is absolutely
obvious, but I spend 4 hours without success :-(((, so please help!

I want to send packets from the Internet to a server running on port 444
(snpp) on an RH8 box.
When packets come from my internal network, everything works, but when I
send packets from the Internet, they are rejected by the RH8 box ( 'sun'
192.168.30.3, single eth0 interface).

When I try the same thing on an old RH7 box ('vega' 192.168.30.1),
everything works.

My configuration:
Internet - ADSL Modem - router (linksys WRT54GS) - Internal network
(192.168.30.0/24)
Port 444 forwarded to 192.168.30.3

'sun' info:
# uname -a
Linux sun 2.4.18-18.8.0 #1 Wed Nov 13 22:52:09 EST 2002 i686 athlon i386
GNU/Linux
# lsmod
Module Size Used by Not tainted
iptable_filter 2412 0 (autoclean) (unused)
ip_tables 14840 1 [iptable_filter]
autofs 13348 0 (autoclean) (unused)
sis900 16812 1
mousedev 5524 0 (unused)
keybdev 2976 0 (unused)
hid 22244 0 (unused)
input 5920 0 [mousedev keybdev hid]
usb-ohci 21288 0 (unused)
usbcore 77056 1 [hid usb-ohci]
ext3 70400 2
jbd 52212 2 [ext3]
raid1 15244 3
# 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

Ethereal (on 'sun') dumps: (XX edited for privacy, command: telnet
xx.xx.xx.xx 444)
-Works OK from 'vega':
No. Time Source Destination Protocol
Info
356 7.031883 192.168.30.1 192.168.30.3 TCP
36496 > snpp [SYN] Seq=2840463986 Ack=0 Win=5840 Len=0
357 7.031915 192.168.30.3 192.168.30.1 TCP
snpp > 36496 [SYN, ACK] Seq=1473874966 Ack=2840463987 Win=5792 Len=0
358 7.032125 192.168.30.1 192.168.30.3 TCP
36496 > snpp [ACK] Seq=2840463987 Ack=1473874967 Win=5840 Len=0
462 11.704524 192.168.30.1 192.168.30.3 TCP
36496 > snpp [PSH, ACK] Seq=2840463987 Ack=1473874967 Win=5840 Len=5
463 11.704539 192.168.30.3 192.168.30.1 TCP
snpp > 36496 [ACK] Seq=1473874967 Ack=2840463992 Win=5792 Len=0
545 16.936389 192.168.30.3 192.168.30.1 TCP
snpp > 36496 [FIN, ACK] Seq=1473874967 Ack=2840463992 Win=5792 Len=0
547 16.936838 192.168.30.1 192.168.30.3 TCP
36496 > snpp [FIN, ACK] Seq=2840463992 Ack=1473874968 Win=5840 Len=0
548 16.936853 192.168.30.3 192.168.30.1 TCP
snpp > 36496 [ACK] Seq=1473874968 Ack=2840463993 Win=5792 Len=0

- Problem when from the Internet:
740 29.017469 84.XX.10.249 192.168.30.3 TCP
40274 > snpp [SYN] Seq=2965742292 Ack=0 Win=5840 Len=0
741 29.017487 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [RST, ACK] Seq=0 Ack=2965742293 Win=0 Len=0
793 32.016237 84.XX.10.249 192.168.30.3 TCP
40274 > snpp [SYN] Seq=2965742292 Ack=0 Win=5840 Len=0
794 32.016254 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [RST, ACK] Seq=0 Ack=2965742293 Win=0 Len=0
971 38.016440 84.XX.10.249 192.168.30.3 TCP
40274 > snpp [SYN] Seq=2965742292 Ack=0 Win=5840 Len=0
972 38.016463 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [SYN, ACK] Seq=1499190741 Ack=2965742293 Win=5792 Len=0
1044 42.012537 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [SYN, ACK] Seq=1499190741 Ack=2965742293 Win=5792 Len=0
1334 49.383630 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [SYN, ACK] Seq=1499190741 Ack=2965742293 Win=5792 Len=0
1806 61.535974 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [SYN, ACK] Seq=1499190741 Ack=2965742293 Win=5792 Len=0
2318 87.035974 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [SYN, ACK] Seq=1499190741 Ack=2965742293 Win=5792 Len=0
3325 135.047696 192.168.30.3 84.XX.10.249 TCP
snpp > 40274 [SYN, ACK] Seq=1499190741 Ack=2965742293 Win=5792 Len=0

'sun' answers systematically a [SYN, ACK] in the opening handshake. The
same thing occurs on other ports.

I can't see any reason for that, any help would be greatly appreciated!

Michel

mgouget hat computer dott org

Found!!
Idiotic reason, I changed the default gateway IP, but forgot to update
ifcfg-eth0 on 'sun' !!

Sorry for polluting the group!!

Michel