Click to See Complete Forum and Search --> : #@$%@! Ip forwarding!!!


sdunn
08-16-2001, 04:43 PM
Okay, I have been trying to get my redhat 7.0 server to send incoming telnet sessions and ftp sessions to my SCO/Unix server for a couple of weeks now. People have given great information to me, but I don't understand what people are telling me to do. I went to linuxdocs.org and read up on Ip masquarding and IPchains. All of this seems to work except for the forwarding.
Here is my rc.firewall script can someone please tell me what is missing or wrong with this script in basic terms. Because I have tried everything everyone has told me to do and obviously I am doing something wrong. Please read my script and give any opinions.

Thanks )
#!/bin/sh
#
#rc.firewall - Initial SIMPLE IP Masquerade test for 2.1.x and 2.2.x kernels
# using IPCHAINS
#
# Load all required IP MASQ modules
#
# NOTE: Only load the IP MASQ modules you need. All current IP MASQ modules
# are shown below but are commented out from loading.

# Needed to initially load modules
#
/sbin/depmod -a
echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
#Flushes first
ipchains -F
#Flushing once again
# Supports the proper masquerading of FTP file transfers using the PORT method
#
/sbin/modprobe ip_masq_ftp

# Supports the masquerading of RealAudio over UDP. Without this module,
# RealAudio WILL function but in TCP mode. This can cause a reduction
# in sound quality
#
#/sbin/modprobe ip_masq_raudio

# Supports the masquerading of IRC DCC file transfers
#
#/sbin/modprobe ip_masq_irc


# Supports the masquerading of Quake and QuakeWorld by default. This modules is
# for for multiple users behind the Linux MASQ server. If you are going to
# play Quake I, II, and III, use the second example.
#
# NOTE: If you get ERRORs loading the QUAKE module, you are running an old
# ----- kernel that has bugs in it. Please upgrade to the newest kernel.
#
#Quake I / QuakeWorld (ports 26000 and 27000)
#/sbin/modprobe ip_masq_quake
#
#Quake I/II/III / QuakeWorld (ports 26000, 27000, 27910, 27960)
#/sbin/modprobe ip_masq_quake 26000,27000,27910,27960


# Supports the masquerading of the CuSeeme video conferencing software
#
#/sbin/modprobe ip_masq_cuseeme

#Supports the masquerading of the VDO-live video conferencing software
#
#/sbin/modprobe ip_masq_vdolive


#CRITICAL: Enable IP forwarding since it is disabled by default since
#
# Redhat Users: you may try changing the options in
# /etc/sysconfig/network from:
#
# FORWARD_IPV4=false
# to
# FORWARD_IPV4=true
#
echo "1" > /proc/sys/net/ipv4/ip_forward


#CRITICAL: Enable automatic IP defragmenting since it is disabled by default
# in 2.2.x kernels. This used to be a compile-time option but the
# behavior was changed in 2.2.12
#
echo "1" > /proc/sys/net/ipv4/ip_always_defrag


# Dynamic IP users:
#
# If you get your IP address dynamically from SLIP, PPP, or DHCP, enable this # following option. This enables dynamic-ip address hacking in IP MASQ,
# making the life with Diald and similar programs much easier.
#
#echo "1" > /proc/sys/net/ipv4/ip_dynaddr


# Enable the LooseUDP patch which some Internet-based games require
#
# If you are trying to get an Internet game to work through your IP MASQ box,
# and you have set it up to the best of your ability without it working, try
# enabling this option (delete the "#" character). This option is disabled
# by default due to possible internal machine UDP port scanning
# vunerabilities.
#
echo "1" > /proc/sys/net/ipv4/ip_masq_udp_dloose


# MASQ timeouts
#
# 2 hrs timeout for TCP session timeouts
# 10 sec timeout for traffic after the TCP/IP "FIN" packet is received
# 160 sec timeout for UDP traffic (Important for MASQ'ed ICQ users)
#
/sbin/ipchains -M -S 7200 10 160


# DHCP: For people who receive their external IP address from either DHCP or
# BOOTP such as ADSL or Cablemodem users, it is necessary to use the
# following before the deny command. The "bootp_client_net_if_name"
# should be replaced the name of the link that the DHCP/BOOTP server
# will put an address on to? This will be something like "eth0",
# "eth1", etc.
#
# This example is currently commented out.
#
#
#/sbin/ipchains -A input -j ACCEPT -i bootp_clients_net_if_name -s 0/0 67 -d 0/0 68 -p udp

# Enable simple IP forwarding and Masquerading
#
# NOTE: The following is an example for an internal LAN address in the
# 192.168.0.x network with a 255.255.255.0 or a "24" bit subnet mask
# connecting to the Internet on interface eth0.
#
# ** Please change this network number, subnet mask, and your Internet
# ** connection interface name to match your internal LAN setup
#
/sbin/ipchains -P forward DENY
/sbin/ipchains -A forward -i eth0 -s 192.168.50.0/24 -j MASQ
/usr/sbin/ipmasqadm portfw -f
/usr/sbin/ipmasqadm portfw -a -P tcp -L 216.68.68.68 21 -R 192.168.50.5 21
/usr/sbin/ipmasqadm portfw -a -P tcp -L 216.68.68.68 23 -R 192.168.50.5 23


[ 16 August 2001: Message edited by: sdunn ]

[ 16 August 2001: Message edited by: sdunn ]

jumpedintothefire
08-16-2001, 06:14 PM
If your policy is to deny, you don't have any rules for the services that you want to forward.

For some samples see: http://www.linuxnewbie.org/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=13&t=004970

sdunn
08-17-2001, 10:15 AM
Hey I used your firewall script and changed it to read my IP's but when i do a ./rc.firewall it says no file or directory found. I know for a fact it is in my current directory because when I do a ls it is there with full permissions. What do I need to do to your file.

sdunn
08-17-2001, 10:44 AM
oK i got the script to run but it comes up with errors saying -d is not used is there something I am supposed to use with $Universe i left it like this becuase i don't know what to put in its place.

sdunn
08-17-2001, 03:36 PM
Here are the errors im getting

/sbin/ipchains: host/network `-d' not found
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: host/network `-s' not found
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: option requires an argument -- s
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: option requires an argument -- d
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: option requires an argument -- d
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: option requires an argument -- s
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: option requires an argument -- d
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: host/network `-d' not found
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: option requires an argument -- d
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: host/network `-d' not found
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
/sbin/ipchains: option requires an argument -- d
Try `/sbin/ipchains -h' or '/sbin/ipchains --help' for more information.
portfw: illegal local address/port specified

jumpedintothefire
08-17-2001, 06:47 PM
opps forgot to define a variable, sorry

UNIVERSE="0.0.0.0"

add that with the other variables

You have to watch the spaces too.

post back if you have further errors.