Hi, I am Frankjp

I am new is the area of routing using Linux and I need someone to tell me what is wrong with my constructed network (OS fedora core 3 with the most recent kernel).
My network is design as follow:

192.168.9.0 network 192.168.7.0 network
PC1<================>PC_Router<==================>PC2
||
( Internet 192.168.0.0 network)
PC1 IP 192.168.9.2 netmask 255.255.255.0 gw 192.168.9.1
PC1 IP 192.168.7.2 netmask 255.255.255.0 gw 192.168.7.1
PC_router
NIC2 IP 192.168.9.1
NIC1 IP 192.168.7.1
NIC0 IP dhcp (192.168.0.8)

I can ping all PC of my subnet and from everywhere. But I cannot ping outside the network. Beside that when I run a client socket program on PC_router and the server of one of PC1 and PC2 , I obtain Connect failed: no route host. However running the Socket server on PC_router and client on PC1 or PC2 d't cause any error. PC1 and PC2 cannot also connect to Internet while PC_router can. I read some answer talking about routing but it could change anything
Could anyone help me?

Thank !

Frank

I also set this
echo 1 > /proc/sys/net/ipv4/ip_forward
and turned in /etc/sysconfig/network
FORWARD_IPV4 =true
other settings are below.

In PC_router

#ip show neigh
shows both PC1 and PC2
#route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.7.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.9.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth2
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0

#ip route show table main
192.168.7.0/24 dev eth1 proto kernel scope link src 192.168.7.1
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.8
192.168.9.0/24 dev eth2 proto kernel scope link src 192.168.9.1
169.254.0.0/16 dev eth2 scope link
default via 192.168.0.1 dev eth0

#ifconfig
eth0 Link encap:Ethernet HWaddr 00:118:6A:36:1A
inet addr:192.168.0.8 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::211:d8ff:fe6a:361a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2510 errors:0 dropped:0 overruns:0 frame:0
TX packets:2181 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1113199 (1.0 MiB) TX bytes:416573 (406.8 KiB)
Interrupt:177 Base address:0xd800

eth1 Link encap:Ethernet HWaddr 00:0E:0C:6E:A5:79
inet addr:192.168.7.1 Bcast:192.168.7.255 Mask:255.255.255.0
inet6 addr: fe80::20e:cff:fe6e:a579/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:245 errors:0 dropped:0 overruns:0 frame:0
TX packets:712 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:36967 (36.1 KiB) TX bytes:115574 (112.8 KiB)
Base address:0xdf00 Memory:fe5e0000-fe600000

eth2 Link encap:Ethernet HWaddr 00:0E:0C:6E:A7:F9
inet addr:192.168.9.1 Bcast:192.168.9.255 Mask:255.255.255.0
inet6 addr: fe80::20e:cff:fe6e:a7f9/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:297 errors:0 dropped:0 overruns:0 frame:0
TX packets:291 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:43383 (42.3 KiB) TX bytes:34885 (34.0 KiB)
Base address:0xde80 Memory:fe580000-fe5a0000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:4876 errors:0 dropped:0 overruns:0 frame:0
TX packets:4876 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:6805928 (6.4 MiB) TX bytes:6805928 (6.4 MiB)

have you enabled NAT on your PC_router?

Dear ilnli,

Thank you for your answer. I am really new in this system.
Could you please tell me how to?
All what I did is to set the routes and gateways.

Frank

What are the routes on the client PC's? Each client PC will need a route to the Subnet of the other set of client pc's.

Hello javaroast,

Thank you for your answer, I think that I set averything in the client PC. I think that the main PC (PC_router) is the one to redirect the income connection to other subnet.
This is the #route -n for both PC client
PC: 192.168.9.2
===========================================================================

Interface List

0x1 ........................... MS TCP Loopback interface
0x2 ...00 0c f1 b9 93 f1 ...... Intel(R) PRO/100 VE Network Connection -
===========================================================================

===========================================================================

Active Routes:

Network Destination Netmask Gateway Interface Metric

0.0.0.0 0.0.0.0 192.168.9.1 192.168.9.2 20

127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1

192.168.9.0 255.255.255.0 192.168.9.2 192.168.9.2 20

192.168.9.2 255.255.255.255 127.0.0.1 127.0.0.1 20

192.168.9.255 255.255.255.255 192.168.9.2 192.168.9.2 20

224.0.0.0 240.0.0.0 192.168.9.2 192.168.9.2 20

255.255.255.255 255.255.255.255 192.168.9.2 192.168.9.2 1

Default Gateway: 192.168.9.1

===========================================================================

Persistent Routes:

None

PC 192.168.7.2
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.7.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
0.0.0.0 192.168.7.1 0.0.0.0 UG 0 0 0 eth0

Do I need something else to set up? Please let me know.

Thank you

Frank