Linux Question

[dyazdani]

My church has a network set up on Novell/Linux. I have never messed with the computers there before and the guy who set it all up is gone.

They asked me to help get their DSL working again, they bought a new copy of "SUSE Linux." Apparently, someone was in the process of upgrading but something happened (only partially completed, etc???) and the DSL quit working.

Is anyone familiar with this OS in case I run into a snag?

[ThomasW]

I'm ignorant about Linux but found this....

http://www.desktoplinux.com/articles/AT7909082870.html

[dyazdani]

Great! A portion of that info is in the SUSE manual, but not near as much.

The biggest issue I have right now is finding their DSL username and PW! I also have no idea how they manage their user accounts or internet sharing, but hopefully it won't require any changes.

[dyazdani]

Well, a bit of progress was made after working until 11:00 tonight on the thing.

I was able to properly install the Linux OS one one of their 3 servers. One server is their main Windows server, one is a spare, and the third was supposed to be for the DSL and Linux. I had to use the spare because I think the other has a bad HDD.

Once I got things installed, I tried to set up the DSL connection. It seemed to go OK, but I couldn't connect.

There is another computer that connects to the switch where DSL works properly. It uses a "bridge" connection, not sure how that works either. I still haven't found where the ISP is set up - I can't find anywhere the ISP username and PW is used. It's got to be somewhere since this one computer works OK.

Oh well, back to the drawing board. If nayone has any ideas, please let me know.

[dyazdani]

I think I may now know what is going on. Possibly the DSL is set up through a router (no one there knows and I can't find it). Therefore, I need to set it up as a connection thorugh the LAN (i.e. DHCP) rather than as a DSL connection.

The other computer that does work with DSL has no ISP information so it has to be stored elsewhere on the network. Since I don't see it on the server that is running, it must be on a router somewhere.

[Kevin P]

What kind of DSL modem are they using? Some have PPPoE routers built in (Westell has them for example). In this case, the router within the modem itself is handling the login to DSL, and then you connect to the modem's router via DHCP.

I'm guessing what you see is a DSL modem connected to a switch, and the switch is connecting all the PCs to the LAN, with no (separate) router in between, right?

[dyazdani]

What kind of DSL modem are they using? Some have PPPoE routers built in (Westell has them for example). In this case, the router within the modem itself is handling the login to DSL, and then you connect to the modem's router via DHCP.

I'm guessing what you see is a DSL modem connected to a switch, and the switch is connecting all the PCs to the LAN, with no (separate) router in between, right?

The modem is a SpeedStream, model 5200 (I think) 52xx anyway. I'll look and see if it has a built in router, it is not evident from the unit itself. They had some instructions referring to a modem/router, but it was for another model number. I want to say the instructions were for setting up PPP-ATM.

Your second statement is correct. The DSL modem is connected to some CAT5 that goes out of sight, across the room, and into a switch.

There are two switches (I say two, the other might be something else). All the CAT5 in the building comes into the back of the units. On the front are many, many connection points. All the cables on the front of the switch go from one slot to another. E.g. "server 1" might connect to slot 45 (comes into the back) and then a short piece of cable connects from 45 on the front to say 85 on the front.

They tell me that to get the one computer working, they connected "something" directly to the network location for that computer. E.g. the computer's network (switch) number is 95 so they connected "something" on the switch to 95 on the switch. I don't know what it was and neither do they. They say the "something" is "DSL" but I'm not certain that is correct as they use the term "DSL" in a broad manner. They also say that the computer is not on the main network (which I believe since they have something else plugged into it's LAN slot).

[dyazdani]

I see where a firmware upgrade COULD have made it possible for the modem to act as a router. I'm sure this is how they have it set up, I can't find ANYTHING else to prove otherwise.

I will have to check where the DSL modem is plugged into the switch and make sure it is connected such that it hits the network. I think the problem might be that they only connected it to that one computer through the switch rather than to everybody. Is that possible?

It's hard to tell because I can't see where the CAT5 comes IN to the switch, all I can see are the short cables on the front.

[Kevin P]

That thing with lots of ports is probably a patch panel. All the CAT5 going into the back of the panel is simply connected to the jacks on the front, and then patch cables are used to connect the CAT5s into the switch or whatever they're connected to. Typically, you'll see two panels: one for the switch and one that connects to the CAT5 cables going through the building. Patch cables (those short cables plugged into the front) are connected between the switch's panel and the patch panel going to the building cabling. Is that what you're seeing?

Do any of the Linux boxes have TWO network cards/ports in them? In particular, if one box had DSL connectivity before, or one box was connected directly to the DSL modem, does it have two ports? If it does, that box could be serving as a router/firewall for the network.

Did the other guy leave any network charts/diagrams? Say to tell you which ports on the patch panels go where? Are there any brand/model labels on the switches/patch panels?

If you could post a pic of the panels, it might help as well.

[dyazdani]

That thing with lots of ports is probably a patch panel. All the CAT5 going into the back of the panel is simply connected to the jacks on the front, and then patch cables are used to connect the CAT5s into the switch or whatever they're connected to. Typically, you'll see two panels: one for the switch and one that connects to the CAT5 cables going through the building. Patch cables (those short cables plugged into the front) are connected between the switch's panel and the patch panel going to the building cabling. Is that what you're seeing?

YES

Do any of the Linux boxes have TWO network cards/ports in them? In particular, if one box had DSL connectivity before, or one box was connected directly to the DSL modem, does it have two ports? If it does, that box could be serving as a router/firewall for the network.

The windows server has two cards, that was my thought as well, but they said the other server handled the DSL (it only has one card).

Did the other guy leave any network charts/diagrams? Say to tell you which ports on the patch panels go where? Are there any brand/model labels on the switches/patch panels?

There is a sheet with the computer vs. switch slot numbers. I'll stop by at lunch and check out the brand.

If you could post a pic of the panels, it might help as well.

I'll see what I can do.

Thanks for the help!

[dyazdani]

Okay, FINALLY made some progress. I was able to determine that the DSL modem IS acting as a router. It has the following properties:

• IP: 192.168.254.254
• PPPoE: 162.40.58.90
• DHCP: 192.168.254. (assigns 1-253 here)
• There is a table of addresses in the "routes" dialog including 192.168.0.10 (this is a recurring address, see ahead)

I was able to connect the Linux box to the internet by:

• Connect directly to DSL modem/router
• Set up one network card with the "default gateway" set to 192.168.254.254 (router IP)

BINGO! Internet on the Linux box. Now, trying to figure out how to distribute. I then connected the second ethernet card on the box to the patch panel and then to the switch. I assigned this second network connection a static IP of 192.168.0.20 (just to test). Findings:

• I COULD ping it from another computer on the network
• I could NOT get on the internet from another computer

I looked at the internet connection setup of the other computer on the network. It was set up to use the proxy server of 192.168.0.10 and port 3168 (or similar) - remember that magic number? (192.168.0.10)

Here's the kicker. Server "1" which is the main server (Windows) also has two network connections.

LAN 1:

• IP: 192.168.0.249
• Subnet Mask: 255.255.255.0
• Def Gateway: 192.168.0.249
• Pri DNS: 192.168.0.10 (there it is again!)
• Sec DNS: 192.168.0.249

LAN 2:

• IP: 192.168.0.12
• Subnet Mask: 255.255.255.0
• Def Gateway: 192.168.0.10 AGAIN!
• Pri DNS: 192.168.0.11
• Sec DNS: 192.168.0.249

SO, does this mean that the Server "1" was actually being used to share the DSL and not the Linux box? FYI: When I got there yesterday, it was the only one with two connections to the patch panel. Like I said above, I now have the second card in the Linux box also hitting the patch panel/switch.

I did take some pictures, I'll post them in a bit.

What would be the best way to share the connection?

[dyazdani]

Pictures:

Patch Panel/Switch:


Switch Close-up (HP Model)


Server 2 (Linux) - Note only one ethernet cable (I connected the 2nd one after I got the DSL going) The DSL is connected directly through the used port in the picture (red cable). The other card now goes back to the patch panel. Then from the appropriately numbered slot on the patch panel to the switch.


Server 1 (Windows - Main Server) - Note TWO ethernet cables

[dyazdani]

One more piece of info. I remember the guy saying they use "rcsquid" as a password somewhere, though he didn't know what for...

Well, rcsquid initiates the Linux proxy server. So it appears that they DID use the Linux box to share the internet.

I still have to figure out how they wired the thing. I think they moved some stuff to get the temporary (non-networked) PC set up with DSL. Then I need to figure out how to configure squid. All the documentation on the net is ugly, command line junk.

[Kevin P]

Have you figured out what box has that IP 192.168.0.10? That's probably the box running the proxy or routing software.

[dyazdani]

It would have to be the "Server 3" which was the "old" linux box. I'm now using 192.168.0.11 which is "Server 2" (bad HDD on S3).

I think the IP issues are at a minimum, what is a big deal now is starting the proxy on the Linux box. It is entirely command line and config file driven. It's really a pain. Do any search on "starting squid" and you'll see...

I'm not sure if there are any alternatices to Squid or not.

[Kevin P]

Are there any specific requirements they have for using Squid? You could just toss a $40 router in place of the Squid box if they just need basic NAT support for sharing the DSL connection. Much quicker than getting a Linux box to serve the purpose.

Another option is Smoothwall... it's a Linux distro ready-made to act as a firewall. It may include Squid already as well.

[dyazdani]

Truth is that they don't know, they just need it working...

I think someone told them to use Linux because it's "safer" It's a real PITA. They just need basic DSL sharing.

How would I use the router in this configuration since there are many computers?

Can I just connect the DSL modem/router to the patch panel or switch and let the internal router's DHCP do it's thing?

[Kevin P]

A router will suit them fine most likely. Especially if they don't have an expert running the network. Connect the WAN port on the router to the DSL modem, and one of the LAN ports to a port on the switch. Set up the router to connect to the DSL, and bingo, you're good to go.

Did you determine if the DSL modem has a router built in? An easy way to test it is to plug it directly into a PC and see if it goes online with DHCP. If it does, and gets a private IP (192.168.x.x) then you won't need a separate router.

How many PCs are on the LAN?

[dyazdani]

Okay, FINALLY made some progress. I was able to determine that the DSL modem IS acting as a router. It has the following properties:

• IP: 192.168.254.254
• PPPoE: 162.40.58.90
• DHCP: 192.168.254. (assigns 1-253 here)
• There is a table of addresses in the "routes" dialog including 192.168.0.10 (this is a recurring address, see ahead)

Yes, it is acting as a router. So I just have to connect the LAN (output) on the DSL modem/router to a input on the switch?

How then do I set up the client PCs to see it for internet? I would just set the TCP/IP to "automatic IP address" or whatever it says right, and the router will assign 192.168.0.xxx to each client?

Would that interfere with their connection to the other server?

Can you also tell me how the switch connects to the patch panel? Basically, why do they have so many connections into the switch, don't they only really need one for the server and one for DSL?

[Kevin P]

Yes, it is acting as a router. So I just have to connect the LAN (output) on the DSL modem/router to a input on the switch?

That is correct.

How then do I set up the client PCs to see it for internet? I would just set the TCP/IP to "automatic IP address" or whatever it says right, and the router will assign 192.168.0.xxx to each client?

Correct again. Set your PCs to obtain IP address and DNS info automatically. It will get assigned by the router in the DSL modem.

Would that interfere with their connection to the other server?

What's the other server run? If it has a DHCP server, you'll want to disable it. Being a server, you may want to assign it a fixed IP address. If the DSL modem is assigning IPs starting at 192.168.0.100-255, for example, use an IP in the range 192.198.0.1-99 for static IPs for servers.

Can you also tell me how the switch connects to the patch panel? Basically, why do they have so many connections into the switch, don't they only really need one for the server and one for DSL?

What you have is a patch panel, with a bunch of jacks (ports) on the front of it. Each port is wired to a network jack somewhere else in the building, that a PC may be plugged in to. The charts you found should map port numbers on the panel to the locations of the jacks within the building (e.g. port 1 goes to Fred's office, port 2 to Jane's office, etc.) The ports on the switch are (most likely) all the same and are interchangeable. To connect a computer (or router, DSL modem, etc.) to the network, you would connect it to a port on the switch. To connect a computer in someone's office or elsewhere in the building to the network, you'd plug a patch cable into their patch panel port and into a port on the switch, and their computer would be plugged into the port in their office.

As for why there are so many things plugged into the switch, in addition to the server and the DSL, the switch also connects all the LAN jacks in the building to the network, and thus all other networked PCs within the building as well. That's what all the wires between the patch panel and the switch are for. Think of the switch as the "central hub" that connects all the PCs on the network together so they can see/talk to each other. To use an audio analogy, think of the switch as being a distribution amplifier for a whole house/building audio system.

[dyazdani]

The other server has an IP address of 192.168.0.12 I think (left my papers at home). I'm not sure though how the other computers "see" it as far as their network setup. I can check one out and see.

I think the cables leaving the server rack go to the patch panel first, then the short cables connect the servers to the switch via the patch panel right?

So connect the DSL router to say port 47 on the patch panel and then connect port 47 on the front of the panel to the switch? I tried that once, but then tested it from the server. It's LAN was already configured a different way and I didn't want to change it.

I might connect that spare PC to the network and use it to test.

Thanks for the help, hopefully this is the last set of questions.

[dyazdani]

I came up to the church at lunch. It does appear that the server is running DHCP - one of the client computers says its IP was "DHCP assigned" and lists the DHCP server as 192.168.0.249

I also tried connecting the DSL router to the patch panel and then the patch panel to the switch. I can't "see" it from its IP (the one you use to set it up). I'm not sure what to do now, is it a result of multiple DHCP servers?

Here is a shot of the DSL router's DHCP settings:



I'd say there are about 20 computers on the network. If I disabled DHCP on the server, what would I have to do to assign IPs to the clients?

[Kevin P]

Ok, I think I might know how it *was* set up before, with the Linux box acting as a firewall.

The DSL modem's DHCP server is set to give out IPs in the range 192.168.254.x. The modem was connected directly to one NIC in the Linux box, which (probably) acquired a 192.168.254.x IP via DHCP from the modem. Let's call this the "WAN side" of the network, for sake of a better term. The 2nd NIC in the Linux box was connected to the switch, and it was assigned the IP address 192.169.0.10. This is why the gateway IP on the clients were set to this, so that attempts to access anything outside the LAN side would be routed through the proxy and out to the DSL modem. Client PCs would also get 192.168.0.x IPs from the DHCP server.

To simplify things, do this. On the router/modem, make the following changes:

Router's IP address (probably on a different page, I don't see it, but it is probably set to 192.168.254.254 now): change it to 192.168.0.1.
Start IP Range: change to 192.168.0.101.
End IP range: change to 192.168.0.254.
Default Gateway: check the "Self" box.

If you could screen-shot the other configuration pages on the router/modem and post them, I can offer other changes that need to be made, such as to enable the internal firewall.

On the server, you'll want to make the following changes:

1. Turn off the DHCP server.
2. Change it to a fixed IP address between 192.168.0.2 and 192.168.0.100, if it doesn't already have a fixed IP in this range.
3. If the clients reference the server by IP address, change it to the new IP. If they use a name, check the hosts file for a name-to-IP mapping that may need to be changed.

Do you know what that server is used for, besides DHCP?

You should be able to plug the DSL modem directly into a switch port, bypassing the patch panel. Unless the modem is in a different room and is patched into the network closet via in-wall cable going into the patch panel. In this case, you'll have to find out which port on the patch panel is connected to the modem, and jumper that port to a port on the switch.

Once you do this, your clients should receive IP addresses in the 192.168.0.101-254 range from the DSL router.

[dyazdani]

Ok, I think I might know how it *was* set up before, with the Linux box acting as a firewall.

Yep, I had this one figured out (the only thing I figured out). They 100% used Squid as a proxy to make it happen.

If you could screen-shot the other configuration pages on the router/modem and post them, I can offer other changes that need to be made, such as to enable the internal firewall.

I will stop by there again after work (1hr longer) and do so.

On the server, you'll want to make the following changes:

1. Turn off the DHCP server.
2. Change it to a fixed IP address between 192.168.0.2 and 192.168.0.100, if it doesn't already have a fixed IP in this range.
3. If the clients reference the server by IP address, change it to the new IP. If they use a name, check the hosts file for a name-to-IP mapping that may need to be changed.

Is it sufficient to simply stop the DHCP service? It's IP on the 2nd NIC is set to 192.168.0.12 so I will just leave it. I guess it uses the 192.168.0.249 IP for the DHCP server.

Confused a bit here... how do I change the IP on the client's setup to the server AND make it so they are also assigned an IP from the DSL router? I've been around in circles on this one...

Do you know what that server is used for, besides DHCP?

Not really, I poked around in the server setup today at lunch - active directory, DHCP, etc. I'm confused because there are 2 NIC cards. One for sure is the DHCP server side (ends in 249). The other one, I assume allows the server a connection to the switch and the rest of the LAN.

Unless the modem is in a different room and is patched into the network closet via in-wall cable going into the patch panel. In this case, you'll have to find out which port on the patch panel is connected to the modem, and jumper that port to a port on the switch.

This is the case - no problem - slot 46 to switch...

Once you do this, your clients should receive IP addresses in the 192.168.0.101-254 range from the DSL router.

So do these end up being the IPs that the server sees FOR the clients as well?

[dyazdani]

arty: arty: arty:

I can now get internet on the client computers. I made all the changes to the DSL router and bingo!

NOW, the issue is communicating between the clients and the server. They can see each other for sure, but I'm not sure how to set it up so the client knows which server/IP to use.

The domain (server) is "CFBC" I tested out one computer, and when I tried to log on it said "Domain CFBC is not available" so I don't know why this might be...

There is light at the end of the tunnel though. (As long as no one shuts down their computer!)

[dyazdani]

OK, so I think the problem mught have to do with properly setting up the LMHOSTS file on the clients. I guess this is so the client knows which domain control to look at for name resolution.

I've read about writing the file, but now I'm stuck on the hex representation at the end of the domain name (how to find it).

BTW:
The domain controller (aka Server 1) has the name "cfbc1" so its full name is "cfbc1.CFBC" I CAN map to a drive on the server, e.g. "\\cfbc1\music" no problem. If I browse in "My Network Places" though, and click on "CBFC" to expand the domain - it says it's not available.

[dyazdani]

Looks like it may be that the cfbc1 server was also handling things as a DNS server.

Is it possible to point to it for DNS from the clients while at the same time having the client PCs assigned an IP from the DSL router?

I guess I can list the server as the DNS and then put the ISP DNS settings in the server and set it up to forward unresolved DNS requests there???

[Nathan P]

I have personal experience with the speedstream router, both the 5200A and 5200B. If your 5200 has 4 lights, then you have to put in a username and password. You will need a server or router to connect multiple computers. If it has 5 lights on the front, then it is a B, and your in luck! This is one cool peice of equipment. It is a 1 port 1 ip router. This means that it acts as a LAN for one computer only. So if you have one computer connected to it, than that is all it can take, according to the specs. But, since it handles all the DSL connection duties on board, there is a way around this. If you have a router, then plug it into the router, and either leave it as is or set it in bridged mode and put the username and password into the router, and then the router will handle dhcp for more computers. If it it just a switch, then you have to become a little more creative. here's what you do.

First, go into your preferences for internet, and set it to manual setup, no dhcp or pppoe.

Next, set your ip to anything in the 192.168.0.xx range. This will put you on the same subnet as the router, which allows you access to the internet.

Next, set the subnet mask to 255.255.255.o

Now, set the DNS server and router to 192.168.0.1

This setup will allow multiple computers to connect to the internet through the router. Make sure to give each computer a different IP, as bad things will happen if you don't. The setup also has the added benefit of making any computer setup this way completely stealth, or firewalled. Noone on the net will be able to see all the way to your computer.

Hope this helped,
Nathan

[dyazdani]

Thanks Nathan.

I've basically tried what you suggested (the DSL modem is in fact a router and can assign multiple IPs).

Problem is that if I use the DHCP in the DSL router then I can't use it on the local server. This presents a big problem since the server also handles local DNS duties.

I tried disabling the DHCP on the DSL router, but I'm not sure how to set up the client computers to connect with it. Is there some other option I need to set in the router (NAT, port forwarding, etc)???

I set up the client TCP/IP as such:

• Typed in my own IP (192.168.0.19) this is what it was before I started
• Subnet is 255.255.255.0
• I set the default gateway to 192.168.0.1 (DSL router)
• DNS set to same as ISP (166.102.165.13 and xxx.11)

No luck. I think I have to have the server IP (192.168.0.249) in for the default gateway in order to handle the local DNS. This is why I thought maybe I could use the router as the default gateway and have it forward unresolved DNS requests to 192.168.0.249 (domain controller, DNS, etc).

Thanks

[Kevin P]

Let the router handle DHCP and gateway duties - it'll assign a 192.168.0.xx IP to each client, and the gateway will be 192.168.0.1. Set your DNS on the client to your Windows server (192.168.0.249). This way your internal names will resolve. Have the Windows server forward outside DNS requests to the ISP DNS (166.102...).

Depending on what options the modem/router has for configuration, you may be able to override the DNS servers there. If you can, then the clients will get everything via DHCP from the router, including pointing to your DNS server on the Windows server. If not, you'll have to set the DNS IP on each client PC manually.

[dyazdani]

Let the router handle DHCP and gateway duties - it'll assign a 192.168.0.xx IP to each client, and the gateway will be 192.168.0.1. Set your DNS on the client to your Windows server (192.168.0.249). This way your internal names will resolve. Have the Windows server forward outside DNS requests to the ISP DNS (166.102...).

When you set up the client TCP/IP for "automatically assign IP address" doesn't that remove the ability to set the DNS? I'll give it another shot...

Depending on what options the modem/router has for configuration, you may be able to override the DNS servers there. If you can, then the clients will get everything via DHCP from the router, including pointing to your DNS server on the Windows server. If not, you'll have to set the DNS IP on each client PC manually.

I tried this as well, there are many options in the DSL router. I wasn't real sure which option to pick and I never got it working right. There is NAT, port forwarding, routing options, etc.

[Kevin P]

You can set DNS IPs in Windows even when using DHCP.

If you can post screenies of the router configuration pages maybe we can find out how to set the DNS there.

[dyazdani]

You can set DNS IPs in Windows even when using DHCP.

If you can post screenies of the router configuration pages maybe we can find out how to set the DNS there.

I will try setting up the DNS IPS again after work...

I finally found a PDF file with some router setup instructions...here is the link.

[Kevin P]

On pages 56-57 of the PDF you posted, there's instructions on configuring DHCP in your router.

In there you can set the DNS IP to be doled out to the clients. Set this to 192.158.0.249. Then you can just let all the clients get IP and DNS info via DHCP and if you ever switch DNS servers, you can just change it in one place instead of on every client.

While you're in there, check the Start IP Range and End IP Range values. Since your router is assigned to 192.168.0.1 and your server is at .254, you want to make sure the DHCP server doesn't give out those addresses to clients. I'd set a narrowish range based on the number of clients on your network, for example, 192.168.0.10 thru 192.168.0.50 if you need up to 40 clients to have IPs.

[dyazdani]

Thanks. I misunderstood the use of the DHCP setup on the router. I was under the impression that if I put the server's IP under the DNS section, that it would not communicate with the ISP's DNS.

[dyazdani]

Here is how I have the DHCP set up on the router.



and the TCP/IP on my "test" client.



I still have the same issue with not being able to find the domain name itself when I try to log on.

I think it loses the actual domain name of "CFBC" when I shut down the DHCP service on the server. The name is actually configured in the DHCP managemen tool, so that makes sense.

This is really a PITA, seems like I can fix one thing but the other breaks... :evil:

[Kevin P]

The DNS IP addresses on your test client are set wrong (last numbers are reversed between them).

With the DNS set up on the router, you can set the clients to "Obtain DNS server address automatically".

On the router, make 192.168.0.249 the primary DNS. Leave the secondary blank, and set up the DNS on your Windows server to forward requests to your ISP's DNS (at 166.102.165.13). Also, for the domain name on the router, instead of alltel.net, use your internal domain name (whatever the Windows Active Directory server is using for its internal domain info). That way, when you reference a server by name, you don't need to fully qualify the name.

Once you do these things, it should work.

[dyazdani]

The DNS IP addresses on your test client are set wrong (last numbers are reversed between them).

I feel so violated, (read: idiot xx) )...

Leave the secondary blank, and set up the DNS on your Windows server to forward requests to your ISP's DNS (at 166.102.165.13).

I tried this once before and it says forwarding is disabled because the server is a "root server" or something like that...