水鸟兄帮忙

我用ADSL上网  eth0接外网
eth1接lan

[root@www waker]# /sbin/ifconfig
eth0      Link encap:Ethernet  HWaddr 00:50:BA:5F:55:AB
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:239097 errors:0 dropped:0 overruns:0 frame:0
          TX packets:225234 errors:0 dropped:0 overruns:0 carrier:0
          collisions:102
          RX bytes:220362259 (210.1 Mb)  TX bytes:31432172 (29.9 Mb)

eth1      Link encap:Ethernet  HWaddr 00:50:BA:5F:A0:F2
          inet addr:192.168.1.251  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:158144 errors:0 dropped:0 overruns:0 frame:0
          TX packets:215948 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0
          RX bytes:23543732 (22.4 Mb)  TX bytes:210344944 (200.6 Mb)

lo        Link encapocal Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:29037 errors:0 dropped:0 overruns:0 frame:0
          TX packets:29037 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0
          RX bytes:11247744 (10.7 Mb)  TX bytes:11247744 (10.7 Mb)

ppp0      Link encapoint-to-Point Protocol
          inet addr:218.2.158.7  P-t-P:218.2.158.1  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1492  Metric:1
          RX packets:5 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0
          RX bytes:227 (227.0 b)  TX bytes:124 (124.0 b)
         
          修改你的例子代码为
         
#!/bin/sh
#edit by waterbird， 2002.4.4
echo "starting the firewall..."

##Ismod the firewall modules
#modprobe ip_tables

##Enable the ip_forward
echo "1" > /proc/sys/net/ipv4/ip_forward

##clear the chains
iptables -F
iptables -X
iptables -F -t nat

##Define the policy
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT

##Define the IP and Interface
LAN_IP="192.168.1.251"
LAN_IFACE="eth1"

ADSL_IFACE="ppp+"

IPTABLES="/sbin/iptables"

#########################POSTROUTING chain
#MASQUERADE
$IPTABLES -t nat -A POSTROUTING -s 192.168.1.0/24 -o ppp+ -j MASQUERADE

##########################FORWARD rules
#accept LAN IP go out
$IPTABLES -A FORWARD -i $LAN_IFACE -s 192.168.1.0/24 -j ACCEPT

#accept come back packets from INTERNET
$IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT


###########################INPUT chain
#for come back from this adsl-server packets
$IPTABLES -A INPUT -i $ADSL_IFACE -m state --state ESTABLISHED,RELATED -j ACCEPT

echo "firewall started! :-D"

结果客户机上不了
而且TELNET不到192.168.1.251

客户机DNS为192.168.1.251
网关为192.168.1.251
什么地方错了
　　　　　　
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想把web访问定向到squid

iptables -t nat -A PREROUTING -i $LAN_IFACE -p tcp --dport www -j REDIRECT --to-
port 3128

结果

ERROR
The requested URL could not be retrieved

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While trying to retrieve the URL: /

The following error was encountered:

Invalid URL
Some aspect of the requested URL is incorrect. Possible problems:

Missing or incorrect access protocol (should be `'' or similar)
Missing hostname
Illegal double-escape in the URL-Path
Illegal character in hostname; underscores are not allowed
Your cache administrator is root.



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Generated Tue, 09 Apr 2002 08:27:51 GMT by (Squid/2.4.STABLE1)　　　　　　
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