[svlug] Masq problem w/ ipchains

[Steve M Bibayoff]

Could anybody see the error of what I'm doing wrong? I know it's 
proably very simple, but I can't see it. 

I am trying to set up a simple MASQ server, but am having problems. The 
reason I know I'm having problems is because when I try to ping from an 
internal machine to an outside machine, the internal ip address is not 
striped off and replaced with the server ip so the request is droped 
because it doesn't know where to go to. I'm currently trying to test 
this with a private address internally and also a private address 
scheme externally. Would that make it fail? Posted below are 
,hopefully, the relevant configurations. Let me know if any other info 
is needed

TIA

Steve

ps. other simi-pert info, RH 7.0 w/ 2.2.16 kernel and all the relevant 
ipchains support built in or modulelized

# ifconfig

eth0      Link encap:Ethernet  HWaddr 00:90:27:FC:75:EB  
          inet addr:172.16.23.200 Bcast:172.16.23.255 Mask:255.255.252.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          Interrupt:10 Base address:0xcce0 

eth1      Link encap:Ethernet  HWaddr 00:90:27:FC:75:EC  
          inet addr:172.20.20.27  Bcast:172.20.20.255 Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:480 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          Interrupt:14 Base address:0xccc0 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:3924  Metric:1
          RX packets:416 errors:0 dropped:0 overruns:0 frame:0
          TX packets:416 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 

sl0       Link encap:Serial Line IP  
          inet addr:172.16.23.201 P-t-P:192.168.3.1 Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:576  Metric:1
          RX packets:3274 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3268 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:10 

# route

Kernel IP routing table
Destination     Gateway    Genmask         Flags Metric Ref    Use Iface
192.168.3.1     *         255.255.255.255 UH    0      0        0 sl0
172.16.22.0     *         255.255.255.0   U     0      0        0 sl0
172.16.20.0     *         255.255.255.0   U     0      0        0 sl0
172.20.20.0     *         255.255.255.0   U     0      0        0 eth1
172.16.21.0     *         255.255.255.0   U     0      0        0 sl0
172.16.20.0     *         255.255.252.0   U     0      0        0 eth0
127.0.0.0       *         255.0.0.0       U     0      0        0 lo
default         172.20.20.27  0.0.0.0     UG    0      0        0 eth1

# ipchains --list

Chain input (policy ACCEPT):
Chain forward (policy DENY):
target     prot opt     source                destination          ports
MASQ       all  ------  172.16.20.0/24       anywhere              n/a
Chain output (policy ACCEPT):