Cannot PING Unix Server 3

[visageuk]

We have UNIX server running a stock system. It has an IP address of 192.0.0.10 and netmask of 255.255.255.0.

We have some PC's running terminal emulators that access it using IP addresses of 192.0.0.XXX. However, we need to run a different set of IP addresses, eg. 192.168.1.XXX. When we change the PCs' IP addresses we can no longer access the UNIX server, even with PING.

Can anyone suggest why this happens? We should still be able to ping the UNIX server shouldn't we? Would the UNIX server configured to block certain IP ranges?

Thanks,

Andy

 

[devilsAdvocate]

Just because they are on the same wire, does not mean "They should be able to find the unix server"..
You have essentially changed the entire subnet for the windoze boxes, think of it as deciding to arbitrarily change the zip code of a block of houses, and then wondering why the mail never gets delivered.
You need to either change the IP of the unix box to be on the same subnet as the windoze boxes, or add a routing statement to the unix box so it knows about this different subnet. look at the routed man page. I'm afraid to ask about your DNS configuration... but suffice it to say that this needs to be thought about as well, or if your not using DNS, you need to update your hosts file.

 

[PHV]

IP address of 192.0.0.10 and netmask of 255.255.255.0
The unix box consider only the 192.0.0 subnet.
However you may add an alias:
1) run ifconfig -a to get the interface name, usually net0 or net1
2) then add an alias, like this:
ifconfig net0 alias 192.168.1.10 netmask 255.255.255.0
3) If now the PCs regain access to the unix server, you may consider make the change permanent accross reboot by creating a /etc/rc2.d/S99alias executable shell script that run the above alias command.

Hope This Help, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[visageuk]

Thanks PHV,

I think that will work. I'll let you know.

To explain a little further, I want to be able to connect to the UNIX server across a VPN using static IP each end.

We have the one network with IP range 192.0.0.XXX of which the UNIX Server belongs with IP 192.0.0.10.

We then have a remote network with IP range 192.168.1.XXX. These are both peer to peer networks running a broadband modem and VPN router. The VPN is setup and working and we can access computers across the VPN fine. However, we cannot access the UNIX Server across the VPN. I've added an alias for the remote IP range but i still cannot ping the UNIX Server. Do i need to tell the UNIX Server about the VPN. Sorry, I'm a complete UNIX novice when it comes to networks and connections.

Thanks,
Andy

 

[stanhubble]

just define a route on the unix system to the VPN gateway.

route add -net 192.168.1.0 ip.of.vpn.gatewayorrouter

 

[visageuk]

Thanks Stan,

This worked a treat! Is a way to display all configured routes?

Andy

 

[PHV]

netstat -r
or
netstat -rn

Hope This Help, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[visageuk]

thanks.

when I add a route is it permanent or do I need to amend any config file?

andy

 

[stanhubble]

no it is not permanent.
depending on which version you have you can
create a file in /etc/rc2.d
usually S99route with the route command in it.

 

[jcoleman]

Hey, Stan
Does that S99route file have to be excutable to work? Just wondering, I have about 20 machines with this file, and after a reboot some retain their default routes and others do not? Just wondering if it may have something to do with the permissions on that file. Haven't really done to much testing on the problem.

Thanks,

 

[PHV]

Yes, it should:
chmod +x /etc/rc2.d/S99route

Hope This Help, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[clegg]

This solved a problem for me too, thanks!!

Clegg