IP address Question

[jezza33]

We have an NT 4.0 Server and 20 Win 98 Clients.

The Server and 4 clients have been given a fixed IP Address from 212.105.179.50 to 212.105.179.54 with a subnet mask of 255.255.255.248. The router has an IP Address of 212.105.179.49. The server and 4 clients have a default gateway of 212.105.179.49.

The server has a secondary IP address added of 10.0.0.1 with a subnet of 255.0.0.0

The remaining 16 clients have fixed ip addresses from 10.0.0.2 to 10.0.0.17 with a subnet of 255.0.0.0

All of the PC's and server have Netbeui installed. I want to remove Netbeui from the network, but have a problem. The problem is that the 16 PC's with a 10.0.0.x ip address cannot connect to the server. If I swap the IP address on the server so that 10.0.0.1 is the primary ip address, then the four clients with 212.105.179.x cannot connect.

Any ideas how to resolve?

 

[Kjonnnn]

Is there a firewall involved in this?

Why dont the 4 NT have 10.... IP addresses.

Somethings amiss with your scheme here.

 

[jezza33]

Kjonnnn, you are quite right that something is amiss! I have walked into this problem at a new client, and I'm trying to get to the bottom of it!

There is no firewall involved here.

If the 4 clients have 10.0.0.x ip addresses, then they will not be able to connect at present to the internet.

Suggestions could be that I install a second NIC in the server and have the 212.x.x.x and 10.x.x.x on the other.

Alternatively, then install proxy server on the server, then allocate 10.x.x.x ip addresses to the server.

Any thoughts?

 

[soonerland]

Maybe I'm missing something...is there a reason that you just don't continue on with the assigned IP addresses on the remaining 16 pc's?

 

[Kjonnnn]

Yea... im tryn to why you have two sets of IPs.

Here we have a firewall. Our internal IPs begin with 10.0.0.0

But externally the IPs show up as 205.0.0.0

What is the IP scope given to your company?

Can you give the other machines 212 IPs instead of 10.

You've to get them on the same IP network.

 

[TheOldMan346]

jezza33,

You've really got a mix-up of factors, there, haven't you. There are a few strange things. Let's try to get it sorted out.

First, a question. Are the Win98 clients FE or SE?

Next, the NT server and the first 4 clients mentioned have 212. IP addresses. These are Class C addresses and are probably assigned from the range given the company by the ISP. These addresses can stand on their own on the internet. Unless these are web or FTP or mail servers, you probably don't want or need this.

Also, the subnet mask of 255.255.255.248 limits the number of addresses that can be used in that range. This is probably done by the ISP. That mask limits the available addresses to just the last three bits of the address. In this case, 212.105.179.50 thru 212.105.179.57.

The other addresses (10.x.x.x) are Class A addresses and would not be usable on the internet as they would conflict with already assigned addresses in the public space. Since they are behind a router, it is OK but it certainly doesn't help in your overall situation. Using a subnet mask of 255.0.0.0 gives you a tremendous amount of flexibility in subnetting and using addresses but from your description, it doesn't sound like it is really needed.

There may not be a firewall but I'd bet the router may be doing some NATing or packet filtering. I would bet that there is also a rule restricting outbound use, as well. The most effective scenario, usually is to use a single or very limited number of public IP numbers for the router on the internet or WAN side and then use a consistent range of private or LAN IP addresses internally for all the servers and workstations. Less of an administrative nightmare.

OK, now for the NetBEUI issue. NetBEUI is an older protocol and was used to implement file sharing in Win95/98. It is simple, easily implemented and fast but it is NOT ROUTABLE. That means that all the computers using it HAVE TO BE ON THE SAME SUBNET. That is why when the server has a 10. address the four 212. workstations cannot connect. When the server has a 212. address the 10. workstations cannot connect. You said you are trying to remove NetBEUI but if my memory serves me correctly, the TCP/IP protocol stack in Win95/98 does not implement the sharing capability like it does in NT, Win2K and XP, [I could be wrong about Win98SE, you should check that.] so you may not be able to remove NetBEUI completely.

Your most expeditious solution may be to change the for 212. workstations to 10. addresses and then reconsider the addressing scheme.

Hope that helps.
The Old Man

 

[jezza33]

You are correct in that this is mixed up!

Just to confirm, I have Win 96 SE on the clients.

I have checked with the ISP, and they have confirmed that we only have 5 real IP Addresses.

As I cannot therefore allocate a 212.x.x.x addresss to more than 5 clients, my other option is to give each client a class a,b or c ip address. I have given one of the internet enabled clients an ip address in the 10.x.x.x range with a subnet of 255.0.0.0 and a default gateway of 212.105.179.49. With this though, I cannot ping the router or beyond. The routers ip is 212.105.179.49.

I am obviously missing something here, but I cannot get my head around how to configure my clients to have a class a,b or c address AND connect to the Internet via my router.

Apologies if I'm being really thick, but I just cannot seem to work this out!!

 

[zoeythecat]

Jezza,

Have you thought about adding a DHCP Server to the network and setting up the range of IP Addresses here? You can then go to each workstation and have them obtain an IP Address from a DHCP Server. Are you familiar with DHCP? If you need any more info on this let me know.

Why do you need to remove NETBEUI? Why can't you just leave that there? For small networks NETBEUI is good is it not?

 

[TheOldMan346]

jezza33,

No need to make it complicated and no need to apologize.

What kind of router do you have? Was it provided by the ISP? Do you have access to or control of it? What is used to connect the other computers together? Hubs? Switches?

I understand you only have 5 IP's and that would not be enough to allocate to all the machines. I would not suggest that. Are you aware that all of the 212. addresses are accessible to the world? I was able to ping several of the units. Unless you are running web, FTP or email servers, I don't think that is a good thing. Instead, I would suggest you use your router as a boundary between the internet (public address space) and your LAN (private address space). You are already doing this somewhat with the 10. addresses. Just continue this approach.

What I had described previously as the most effective scenario is to use one IP assigned by the ISP to the router and then everything else on your LAN side would be numbered as you see fit. This is your PRIVATE address space. Since you do not have a lot of equipment spread all over, I would suggest class C addresses. Something in the order of 192.168.x.x is very commonly used. Since you already have a number of machines using 10. addresses, there's no harm in continuing with this but you might want to reconsider the address scheme at a later date.

A basic router usually has two interfaces unless it has an integrated switch or is a multifunction unit. We'll simply call them WAN and LAN interfaces. Your router's LAN interface is assigned 212.105.179.49. I am guessing that the WAN interface is assigned some other number that the ISP is using. Here is where I need to know what other network gear you've got. We need to create a "route" or a way for the packets to get from your 10. addresses to the 212. addresses. If you have access and control of the router, this can simply be done by changing the LAN interface to a 10. address and creating the route in the router. Then you would only need to change the IP addresses of the computers that already have the 212. addresses. If you don't have control of the router but have a switch, we can do it there. If all you have is a hub, then it will take some doing.

Why don't you digest this and post back with the make and model of the router and describe what other gear you have. Then we'll go from there.

The Old Man

 

[seanos]

Sorry if i seem to be thick (been out of this game for a while), but wouldnt it just be easier in all cases to assign the internal ip range of his machines with the 10.0.0.x address (10.0.0.1 being the server), and then get a router and firewall (set up as 10.0.0.200 for example), connect them straight to the hub and set them up to handle all connections to the outside. This way, all the machines are secure, and wont be accessible from the outside, and all machines should be recognisable on the network?

Sorry if this isnt helping matters, but its never failed for me.

Seanos

 

[TheOldMan346]

seanos,

Yes, that's what I suggested in my 5/14 post. Apparently there is more involved as jezza33 says this was done to one of the workstations but was unable to ping the router or beyond. Might just be the subnet mask but that's why I wanted to know a bit more about the environment.

The Old Man

 

[zoeythecat]

Oldman and Seanos,

Would a DHCP Server fit into this equation at all?

 

[TheOldMan346]

zoeythecat,

It would, absolutely. That is something that could be done as part of a revamp of the addressing scheme. Right now, I think it would introduce a level of complexity that would not help the situation.

DHCP servers are most helpful where you have a number of mobile machines, like laptops, or frequent changes. I don't sense that is the case here but it is certainly worth considering.

The Old Man

 

[seanos]

Zoeythecat,

Dunno really. I ditched the DHCP server on our system and went for static IP's all round, suppose its because i'm just stuck in my ways but i find it easier and much more stable than using DHCP. You know you'll never get ip conflicts when you assign them yourselves.
I think it had something to do with the fact i couldnt ping my router when i used it......

As for the problem above tho...possible solution is to change your subnet mask to 255.255.255.0

this would bring the third node into play.....it might help.

 

[zoeythecat]

Oldman,

Sorry to disagree with you. In this case he is using Static IP for all of his client PC'S. I think having a DHCP server setup does not complicate things. It appears his current situation is more complex having static IP Addresses all over the place. In my opinion this is an Administrative nightmare. Having a DHCP Server setup will take care of the IP Addresses for him. You can also define the 2 subnets, the range of IP Addresses he wants his clients to use, the gateway, DNS. I'm sure I don't have to tell you about DHCP. But help me understand why his current sitation is less complex than adding a DHCP Server? This would be less of a hassle especially as new workstations get added to the network you have to keep track of the static IP's where a DHCP Server does the work for you.

He also may want to consider adding a WINS server. This may help resolve his problem. I don't think removing NETBEUI will help resolve his problem. Not sure why he thinks he needs NETBEUI removed.

Just trying to offer some insite here. I honestly think DHCP and WINS may help.

 

[zoeythecat]

Seanos,

I guess I can understand where you come from. I've been working with DHCP Servers for 6 years and I have never seen any IP Conflicts or any problems at all. DHCP is definitely a better solution than Static but that is just my opinion. I think in Jezza's case the static IP is giving him more problems and making his situation more complex.

Again, just my thoughts. I am not second guessing you guys. It can work both ways Static IP and DHCP.

 

[seanos]

just been reading through his problem again.
I'd say leave NETBEUI alone, set up the server so that it has a SINGLE ip address in the 10.0.0.x region....delete the second ip address, and then re-assign the 4 machines that dont work with new ip addresses in the same 10.0.0.x scheme.

Re-assign the address of the router so that it is within the same scheme, making sure it is within the range...(which could have been the problem all along) and then kick back and party

Problem solved.......maybe.

 

[TheOldMan346]

zoeythecat,

Actually I agree with you. I'm not saying the static addresses are easier than DHCP. I'm saying that for jezza33 to take that approach now would involve bringing up a DHCP server function and changing the configuration of EVERY computer. As I suggested earlier, there may be a simple solution of changing the IP addresses of just 4 machines. But we need a little more information to be sure of what is going on.

For the future, WINS and DHCP would make jezza33's life a lot easier.

The Old Man

 

[TheOldMan346]

jezza33,

Did yiou get this worked out?

The Old Man