Multiple IP's

[elboro]

I have just recived an e-mail informing me that my requested IP's have been assigned to me, BUT i have not idea how to configure my router to assign these IP's to each of my computers. Could I please have some help with this matter. I have a netcomm nb1300.

Thanks, ElboRo

[Sadin]

You don't need to have the router assign them to you, all you need to do is to make sure that the router knows about those addresses. Let's say that you were given the range 202.154.10.8/30 (which is 4 addresses, but 1 of those is the network address, 1 is broadcast) then your router needs to know to route any packets that go to those addresses via its ethernet interface (or usb port in case that you have one of those, i'm not sure what your netcomm is).

So somewhere inside your config for the netcom you need to have a route that says something very similar to this:
202.155.10.8 netmask 255.255.255.252 via A.B.C.D on ethernet1
Were A.B.C.D would be the internal address of your netcomm router.

Once you have this figured out then all you need to do is go to each PC, set its address to be one of those in the range and set its gateway to be the A.B.C.D address.

The tricky part here is that 4 IP addresses that Swiftel give you, really means 2 addresses (+1 that you have normally). The reason why I say 2 and not 4 is above, 1 of them is the network and one is broadcast. There is a condition where you may be able to use all 4, but I can't remember exactly. I have to admit that I am guessing this part, since I don't exactly know how Swiftel alocates you these addresses, but if a range, such as what I mentioned above (202.155.10.8/30), is used then you really only have 2 of those addresses. There is another catch, one of those 2 that you can use, has to be allocated to the internal interface (the ethernet) if you wish to do normal routing. So in reality 4 addresses really mean 1 extra PC :)

I imagine the way you could utilise all 4 addresses would be to do 1-1 NAT on your router for those 4 addresses, where each of those addresses would correspond to 1 (and only 1) PC.

Since this all can get very confusing I better leave it at that, if you want to know more feel free to ask, but there is plenty of info on the net about routing/NATing.

[elboro]

Thanks alot, but i still dont understand how to do it. I didnt think it would be so complicated!
OK lets say that theoretically (if thats how u spell it) i had 202.154.104.120 / 29 given to me, what does the 29 mean? and is this the first of 8 IP's? and where do i enter it into the router?

Would appreciate some help as I am getting very frustrated :(

Thanks, ElBoRo

[Sadin]

Ok I'll tell you what the 29 means first, but before I can help you out further you have to tell me exactly what you're trying to do. Also I dont have access to that particular modem, so I'll try explain roughly what the procedure is and if you look in the modem's manual you should be able to find the details on how to do ti.

The 29 means that first 29 bits of the address 202.154.104.120 are used for the network address. (fyi: total address bits=32)
This is the same as saying your netmask is 255.255.255.248.

202.154.104.120 is the network address. (i.e. unusable for a PC)
202.154.104.127 is the broadcast address of your network (i.e. also unusable for a PC) so you really have 6 addresses available for your interfaces. 121 until 126. Usually the first address in a network (i.e. 202.154.104.121) would be used as the address of the network interface of your gateway (i.e. your modem). The rest of the addresses could be allocated to your PCs.

So tell me exactly what you're trying to do and I'll try look up some documentation about your modem on the net and try explain in those terms what to do.

[elboro]

ok well I am trying to give each of my PC's (of which there is 6) a static internet ip, not a private address. Thats it.

My modem is a Netcomm 1300 and the is no explanation at all in the manual on how to do this.

Thanks, ElBoRo

[elboro]

Is there a swiftel tech support person that can help me with this matter?
It seems unfair to expect me to work it out by myself (Im not some networking freak), considering i am paying $80 dollars a year and i cant even get a little bit of help, i rang up tech support and and they didnt seem to happy to help me or even explain how to do it.

ElBoRo

[Matt]

Originally posted by elboro
ok well I am trying to give each of my PC's (of which there is 6) a static internet ip, not a private address. Thats it.

My modem is a Netcomm 1300 and the is no explanation at all in the manual on how to do this.


Typically you don't "do" it in the modem/router -- you "undo" the private addressing by disabling NAT (Network Address Translation). Try looking at it from this angle (I have no idea about the Netcomm specifically), remembering the modem needs to be configured as a router (or be sitting in front of a router).

[Matt]

Originally posted by elboro
It seems unfair to expect me to work it out by myself (Im not some networking freak), considering i am paying $80 dollars a year and i cant even get a little bit of help, i rang up tech support and and they didnt seem to happy to help me or even explain how to do it.

$80 would get you about half an hour's time from a network engineer who knew enough to help you.

I imagine $80 a year would hardly cover Swiftel's delivery/maintenance cost on this service, which is an entirely separate "convenience" to the ADSL service their techs are employed to support, and you should just be thankful they even provide it (try getting it elsewhere :) )

Just ask nicely here, and do some research yourself, and I imagine you'll get it figured out. (I'd also recommend understanding exactly what you're doing before putting six machines on the public net, or you'll become your own DDoS platoon within a day or two. :D )

[elboro]

Originally posted by Matt
$80 would get you about half an hour's time from a network engineer who knew enough to help you.

I imagine $80 a year would hardly cover Swiftel's delivery/maintenance cost on this service, which is an entirely separate "convenience" to the ADSL service their techs are employed to support, and you should just be thankful they even provide it (try getting it elsewhere :) )

Just ask nicely here, and do some research yourself, and I imagine you'll get it figured out. (I'd also recommend understanding exactly what you're doing before putting six machines on the public net, or you'll become your own DDoS platoon within a day or two. :D )


Yeh well i dont need help every year, just 5 minutes of help and that is it, and you really think i have just been sitting here asking in one forum and not reading up about it in countless books and on the net :rolleyes: , well think again, becuase that is all i have been doing for the last 4 days. Asking swiftel is my last resort!

[Sadin]

To be honest, I agree with Matt and I can't blame swiftel techs for not helping out with this. Two reasons for this, firstly I think its assumed that if someone wants to do this that they know what they are doing and have very good reasons for doing so. Secondly there are a million and one different modems and ways of configuring this and its impossible to expect swiftel (or anyone elses) support to know about configuring all these modems.

From what I've told you earlier you should get the picture though, and all you have to do now is to make sure that you configure it into the modem. So I'll summarise the changes for you.

Your modem has 2 interfaces used at the moment, one is your phone line and the other I'm assuming it's ethernet. (if it is usb then I have no idea why you are doing what you're doing :)
This ethernet interface now has an address of 192.168.1.1. You need to change this to your first address in your given range. If you were given 202.154.104.120/29 then this would be: 202.154.104.121. Put the netmask as 255.255.255.248. When you do this you can only connect 5 more computers to that hub in the address range 202.154.104.122-126. The .127 address is your network address and cannot be used.
That's the first thing that needs to be changed. Second, somewhere in advanced settings there should be an option to turn off NAT. I have no idea if your modem supports this or not. If its not there you cannot use your modem to do routing like this. You'll need something better.
Third thing that has to be verified is routes. Somewhere in advanced settings again you should have a list of static routes present in the modem. If the route 202.154.104.120 is not there, then you have to add it for the above netmask and ethernet interface.

By the way, if you press apply for the above address, then you can't access your modem anymore on the 192.168.1.1 address. you need to use the other address 202.154.104.121. Also if you want to access it on this address, you gotta make sure your PC has been configured for this subnet. Otherwise you may find it very hard to reach the configuration webpage. As you can see this makes it a potential security hazard as well as someone may be able to get to the modem config page from the Internet. (I dont really know if netcomm has any protection for this or not)

When you read the above it will no doubt confuse you a bit. This is because this kind of stuff is not exactly straightforward. So before you progress take some time to read about routing.

If you find that the above doesn't work with your modem, you can shift to plan B. Put your modem in bridged mode (so it doesnt do routing, but instead assigns an address to your ethernet card for one of your PCs.) Put a second network card in that PC and configure it's address to be 202.154.104.121. As long as you make sure that IP forwarding is turned on (this can be done on both windows and linux) that's all you would have to do. This way you'd be able put all 6 of your computers online.

If you go either way, make sure you checkout some firewall software that you could run. Otherwise things could get extremely nasty as Matt has pointed out.

[forumadmin]

"It seems unfair to expect me to work it out by myself (Im not some networking freak), considering i am paying $80 dollars a year and i cant even get a little bit of help, i rang up tech support and and they didnt seem to happy to help me or even explain how to do it. "

I can understand how you feel but I think you need to understand that the $80.00 you paid for the additional IPs is for a service that is supplied to you at Swiftel's cost for those IP addresses. We do not make any profit out of providing them and we do not offer any consulting in their use.

Swiftel do not, nor do Swiftel claim to, provide support for customer's networks or even their PC or modem set ups. This is made quite clear on our pricing/plan pages.

The Swiftel support engineers often will help if they have the time (against their job description and instructions) because they are nice and caring people.

However Swiftel's support engineers are employed to quickly resolve ADSL connection issues from our PoP, through the Telstra DSLAM and the individual line from the exchange to the user's modem.

Not beyond that.

We hope that this forum, and other forums like it, will be able to pool the collective wisdom and experiences of Swiftel and other ADSL users to help an individual user sort out specific issues/problems that go beyond actual ADSL connectivity.

Networking issues that you are involving yourself with are quite complex and need a very real level of experience with both the concepts you are trying to implement and the hardware, firmware and operating systems you are using.

Those aspects of computer usage are not part of Swiftel's service.

[elboro]

OK

[elboro]

wooohooooooooo

THANK YOU SADIN

that last bit of info was da biggest help, i wis you had of said it that way before! :D

anyone that has this problem just read the last post by sadin, its actually not that hard, the only bit i didnt understand was the subnet. but who cares, its working :)

thanks so much, ElBoRo

[whoozle]

Originally posted by Sadin
(if it is usb then I have no idea why you are doing what you're doing :)

Could you elaborate on why you say that? I'm not exactly new to networking, but I have 0 experience with USB modems. In my understanding, it could operate as a router (connected to a computer) and then the computer could act as a router (non-NAT) to pass on the packets, can't it?

If it's acting in bridge mode, then it can connect to the computer via USB still and the computer will then act as a router/NAT router...so, I guess I don't understand your logic...please explain for my benefit. :)


If you find that the above doesn't work with your modem, you can shift to plan B. Put your modem in bridged mode (so it doesnt do routing, but instead assigns an address to your ethernet card for one of your PCs.) Put a second network card in that PC and configure it's address to be 202.154.104.121. As long as you make sure that IP forwarding is turned on (this can be done on both windows and linux) that's all you would have to do. This way you'd be able put all 6 of your computers online.


Hmm, ok...So, what would the "first" NIC be configured for? the LAN? (eg. 10.0.0.0/8)

Also, would the modem (in bridged mode) be connected to the "first" NIC, or the "second" NIC? I don't think your description is entirley clear on that point...

Also, I am unclear as to why you would only need to enable IP forwarding...don't you need to check your routing, whether you use "plan A" or "plan B"?

Thanks.

[Sadin]

All I'm trying to say about USB is that I don't really trust USB for these kinds of things. Nothing really wrong with doing it though :) You could easily have one network card connecting to the LAN and the modem in USB bridged mode.

In my example I was ignoring USB completely, so that's why for plan B I indicated 2 network cards. One is for the modem (has no IP configured for it if its in bridged mode) and the second card needs to have the network address. Now in elboro's situation this needs to be a public IP address (i.e. 202.whatever) Because he wanted all of his PCs to have a public address there is no 10.0.0.0/8 lan. In the case that you are doign NAT (either with the modem or with windows/linux connection sharing) then you would have a 10.0.0.0/8 (or any other private range, e.g. 192.168.x.x) address on the second NIC (the one thats connected to your lan).

To answer your last question, if you don't have IP forwarding on, then you can't have routing :) because "IP forwarding" is "routing". I don't quite understand what you mean by "don't you need to check your routing"...

[whoozle]

Originally posted by Sadin
All I'm trying to say about USB is that I don't really trust USB for these kinds of things. Nothing really wrong with doing it though :) You could easily have one network card connecting to the LAN and the modem in USB bridged mode.

Ah, ok...just from the way you described it, you made it sound like it wasn't possible with USB, which made me confused.


In my example I was ignoring USB completely, so that's why for plan B I indicated 2 network cards. One is for the modem (has no IP configured for it if its in bridged mode) and the second card needs to have the network address. Now in elboro's situation this needs to be a public IP address (i.e. 202.whatever) Because he wanted all of his PCs to have a public address there is no 10.0.0.0/8 lan. In the case that you are doign NAT (either with the modem or with windows/linux connection sharing) then you would have a 10.0.0.0/8 (or any other private range, e.g. 192.168.x.x) address on the second NIC (the one thats connected to your lan).

Let's say you're given 202.154.0.0/29, say.

Ok...so I am guessing in your example, modem is in bridged mode and connected to NIC1. You don't configure NIC1 (well, it isn't necessary) and as it is in bridge mode, NIC1 will get a public address, eg. 202.154.0.1, say.

Now, the 2nd NIC connects to the LAN. So, according to your example, "the second card needs to have the network address. " So, that would mean, you would give the 2nd NIC 202.154.0.0, or did I misinterpret your example? (After all, 202.154.0.0 is the network address, right?)


To answer your last question, if you don't have IP forwarding on, then you can't have routing :) because "IP forwarding" is "routing". I don't quite understand what you mean by "don't you need to check your routing"...

What I mean is, more than just merely enabling IP forwarding, wouldn't you need to check your routing table to ensure that it is all correct?

[Sadin]

I didn't mean "network address", rather I meant an address from the range of the network. :) a bit of a misunderstanding.

When you put in an address on an interface you don't need to add any routes for it. A route for that subnet is automatically created. For example let's say you add 192.168.20.1 with netmask 255.255.255.248 to an interface (NIC). As soon as you have done that, do: route print on windows or netstat -nr on linux and you will see a route saying:
192.168.20.0 255.255.255.248 gateway 192.168.20.1 and the interface it is on...

Now if you don't put IP forwarding on and lets say you have another interface with the range: 10.0.0.0/8 so you'd have a route:
10.0.0.0 255.0.0.0 gateway 10.0.0.1 on another interface, then you will not be able to contact the 192.... network from your 10.... network computers. As soon as you put IP forwarding on then your different interfaces can talk to eachother, i.e. packets are forwarded between them = they're routed :)

Let me know what you are trying to do exactly and I'll try help you out as well.