Billion UK Forum

Hello All,

[apologies for the long nature of this query, but you'll understand this is for some clarity]

I’m new to this forum and tried to search (including with Advanced search) and I get 0 messages even for trivial search keys, and the search tool didn't look credible at all.

I'm afraid, therefore, this question may have been asked already and apologies if this is a repeat query.

My question is with regard to the 7800N router issuing Fixed IP addresses to clients. Until I acquired 7800N, I had no problem with this issue (having used known brands such as 3COM and Netgear before 7800N).

What I want to achieve is for the Router, as DHCP, to do "address reservation" for clients. So, an address is reserved for a given MAC - simple concept – and this, in effect, implements fixed IP address (assuming things don't go haywire).
Now I see Billion [needlessly] segregating DHCP function" and "Fixed IP allocation" (or am I missing something?), to the extent that the fixed IP addresses and DHCP addresses are mutually exclusive. To what benefit?

For my setup I want the router to work as DHCP server with address reservation – if a client requests for an address, the router checks if a reserved address exists for the corresponding MAC and allocates that IP (fixed IP achieved), else whatever is available (dynamic IP achieved).

This allows the clients to get the IP addresses automatically while the fixed IP is achieved by address reservation in the router (through MAC/IP table). There are numerous advantages to this approach and I do not even see any disadvantages of this. I had this feature with routers from about 10 years ago, but not with 7800N, unless I'm missing something; in other respects 7800N performs great and no problem.

Am I missing something with regard to achieving fixed IP allocation via address reservation as part of DHCP? Your help is very much appreciated.

My router’s firmware is 1.06e; does 1.06g perhaps address this issue?

Rob.

It was always my understanding as DHCP is dynamic, you would get a different address every time you booted your computer and that would auto change a pre-assigned addresses within the pool, or it could conflict with other clients/devices using the DHCP pool when they were switched on and that is why static IPs are usually assigned outside of the DHCP pool, but I could be wrong or of have misunderstood your concept.

I've also no experience of the other routers you've used or what could be achieved with them.

I agree with what you say Tomken and DHCP is dynamic as the acronym is " Dynamic Host Configuration Protocol". What I am after is for DHCP to work hand-in-hand with address reservation. I cannot even understand why fixed IP editing was necessary - may be this is for something I do not know. I like DHCP - but within that I want the router to assign the address I reserve for a given MAC. I don't kown how (or if) this can be done. At the same time I find it hard to believe for router this sophisticated not doing this. This is where I doubt myself (the 'missing something' in my original query).

Rob

I'm not too sure about your version of the firmware, but to do what you describe on 1.06g, I just had to go to (Advanced) Configuration > LAN > DHCP server and then click on "fixed host" at the bottom. If you're familar with DHCP reservations, you should be right at home here. Just enter a host name, the MAC address of the device and the IP you want it to have (outside of your DHCP range)... Restart networking on the device and it should pick up the new IP

It does seem to be oddly segregated from the main DHCP table as you say, which is a little annoying, but the functionality you describe is definitely there...

Thanks teaser,

Firmware 1.06e is exactly as you describe so nothing has changed with regard to IP address allocation with the router as DHCP server.
What doesn't make sense to me is why the "fixed address" has to be outside of the DHCP. Let me illustrate with an example:

DHCP pool: 192.168.1.10 to 192.168.1.99

from this pool I want to reserve address 192.168.1.10 for MAC_ADDRESS_1 (symbol used - in reality like 01:02:03:AB:AF:06 hex numbers) and reserve address 192.168.1.20 for MAC_ADDRESS_2

The router will dynamically allocate from the pool except 192.168.1.10 and 192.168.1.20 will be allocated to clients with MAC address MAC_ADDRESS_1 and MAC_ADDRESS_2 respectively. This is an elegant way of doing DHCP because you achieve both dynamic and fixed by employing address reservation. This makes the 7800N way of fixed address unnecessary. I cannot even see the advantage of fixed IP the 7800N way but disadvantages.

I hope this will narrow down my question. Does 7800N handle DHCP + address reservation as illustrated with the above simple example?

To the best of my knowledge, it isn't possible for the 7800N to handle reservations in that exact way. (I'm open to correction of course!)

What you're getting at is essentially the same way DHCP reservations on Windows server work, whereby you can add a reservation within (or without) the range, and this will always show up on your address leases table... I'm guessing that it would probably need to go to Billion head office as a feature request if you want it to work in this way...

You could always work around this by starting your DHCP pool at 192.168.1.15, then assigning 192.168.1.10-192.168.1.14 fixed IPs (I personally use the default pool settings, then .200, .201 etc for all of my fixed IPs, which I find easy to remember...)

I agree with you teaser - I have gone through the long PDF manual and there is no indication of DHCP server working the way I wanted. I also upgraded the firmware to 1.06g a while ago, and so far I see nothing being different at GUI level before and after firmware upgrade.

The IP pool used is as a simple example - yes I do use more user-friendly (easy to remember) ranges/formats.

I am surprised finding myself going backward here. Even routers a decade old did the DHCP as described.

Even servers such as Windows Server 2003/2008/2008 R2 (I presume the latest) do DHCP by mixing address reservation, because this is the best way.

The advantage of DHCP with IP address reservation is that:
1) clients do not have to be configured at all (they get IP automatically which is the default) - they ask for IP but can get fixed one if reserved. Even if one programs with fixed (as on Windows) that works too, but why bother when you can do centrally with a router as DHCP server (assuming this is possible!).

2) here is a clear winner - if you have multiple networks you can easily join any network - if wireless - you just choose the wireless name and get connected (yes most certainly with login). Even for wired LAN you can use a mechanical switch (RJ45 changeover switch) or some clever switching. Obviously this depends on what you want to do but the 7800N gets in the way here. Since the address is picked dynamically (so the client thinks) but the router assigns what you want to - and it always works. Here you can see the DISADVANTAGE of the 7800N fixed IP as a major obstacle. This advantage will only be evident if you want a KNOWN IP for a given application so this is a different subject altogether. If your need is just to the point of assigning IP (just get connected) what I describe here may not even make sense. As a crude example, if you want your smart phone interact with some intelligent network device, mediated by some software, in the scheme of things having a predetermined IP makes setting up and testing a lot easier. That is where DHCP + address reservation makes things straightforward.

I would say, 7800N's segregation of dynamic pool and fixed IP totally unhelpful. The fixed IP should have been address reservation within DHCP and without bothering about the fixed pool.

Certainly this will be top on my wish list (in addition to missing labels that otherwise compels you to memorise MAC address vs. friendly client names (or refer to a table of MAC/client name - still hard way) and among many other wishlist).
Well, I could also return the router as Amazon (in my experience) are quite happy to refund if performance is unsatisfactory (which is the case from my point of view).

Oh! well no router is perfect!

I agree that the 7800N does it differently to my previous routers but I don't find it an issue the way it works quite honestly.

Whether the fixed IP addresses are within the DHCP range or not to me is irrelevant and there no doubt would be others who prefer it this way.

I've indicated that the advantage of "dynamic pool with address reservation" will only be apparent if you do something beyond network connection, such as custom configuration for network development and testing.

That said, I am still baffled why Billion did it the hard way.

DHCP with address reservation achieves both dynamic and fixed address in a clean/elegant way; for example, clients start with a default of acquiring IP addresses automatically with the DHCP protocol.
Separating dynamic pool and fixed pool - the Billion way - although may work to get devices connected, there comes a point where it would be troublesome and even fail (as highlighted by this question). I see no benefit of separate dynamic pool and fixed pool but more effort in configuring and trouble.

Is it customary to get more authoritative comments from people connected with Billion on this forum? If so, can someone comment on if there was any reason behind (dynamic pool + fixed pool) in lieu of the single (dynamic + reservation) pool.

Thank you all for your interest.