Hi there, I'm trying to setup a network containing: a Sun server with private IP 192.1.1.1 several hosts with private IP 192.168.2.x a hubswitch a linux server as a gateway to the internet, with LAN iface IP 192.168.3.254 and WAN iface. everything working except the hosts cannot ping to Sun Server. Can it be solved by modifying routing table in the linux gateway? I dont have more router to split the server from the hosts network. The IP address of Sun Server cannot be changed because of that IP have been Hard-Coded into internal accounting system build by Software Department, and they dont want to modify their source. Thanks in advance.

Why would ANYBODY want to hardcode an IP address? Even if the address does not change, one day it might and I would want the ability to move the system and not have to ask/tell another department to FIX there code.

They are going to have fun when IPv6 comes out!=o) How about adding another NIC to the linux box and makingg it multi-homed?

Hi guys, today I try to make the problem simple. I want to combine 172.25.123.x with 192.1.1.x i use smoothwall pendolino for the linux box, using 2 NIC, configured as: eth0: 172.25.123.234/24 broadcast at 172.25.123.255 (this is for LAN iface) eth1: 172.26.123.234/24 broadcast at 172.26.123.255 (this iface is connected to ADSL modemrouter. my internet connection is ok) now i try to make an alias for eth0 with ifconfig: ifconfig eth0:1 192.1.1.234 netmask 255.255.255.0 broadcast 192.1.1.255 my ifconfig show: [root@smoothwall root]# ifconfig eth0 Link encap:Ethernet HWaddr 00:04:76:8D:7F:C0 inet addr:172.25.123.234 Bcast:172.25.123.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:565340 errors:0 dropped:0 overruns:1 frame:0 TX packets:173947 errors:0 dropped:0 overruns:0 carrier:6 collisions:151 txqueuelen:100 RX bytes:62145247 (59.2 Mb) TX bytes:172310064 (164.3 Mb) Interrupt:5 Base address:0x7400 eth0:1 Link encap:Ethernet HWaddr 00:04:76:8D:7F:C0 inet addr:192.1.1.234 Bcast:192.1.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:5 Base address:0x7400 eth1 Link encap:Ethernet HWaddr 00:40:05:10:69:2C inet addr:172.26.123.254 Bcast:172.26.123.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:168957 errors:0 dropped:0 overruns:0 frame:0 TX packets:540111 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:169192024 (161.3 Mb) TX bytes:59181830 (56.4 Mb) Interrupt:10 Base address:0x7000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:166 errors:0 dropped:0 overruns:0 frame:0 TX packets:166 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:23034 (22.4 Kb) TX bytes:23034 (22.4 Kb) my route show: [root@smoothwall root]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 172.25.123.0 * 255.255.255.0 U 0 0 0 eth0 192.1.1.0 * 255.255.255.0 U 0 0 0 eth0 172.26.123.0 * 255.255.255.0 U 0 0 0 eth1 default 172.26.123.234 0.0.0.0 UG 0 0 0 eth1 the 192.1.1.0 line have been added automatically. as u see, my ifconfig print eth0:1 for 192.1.1.234, but in my route, it say 192.1.1.0 is using eth0. -now i can ping to 192.1.1.x. from linux box. -host using 192.1.1.x (which gateway is set to 192.1.1.234) can ping to linux box, can access internet but cannot ping to 172.25.123.x my sysctl net.ipv4.ip_forward show: net.ipv4.ip_forward=1 help me please.

The 192.1.1.0 with a subnet of 255.255.255.0 just means any traffic for 192.1.1.1 to 192.1.1.254 will be routed through eth0

try posting in the networking forum, or get a good book detailing basic networking. you need some refreshing on the basics of subnets.

thanks rick, i think i come to wrong forums.