Plusnet 2704n Router Fault

[#1]

So I've reported to Plusnet support that my shiny new "business" Plusnet (Sagemcom) 2704n router has a major issue with port forwarding. I painstakingly illustrate that the router forgets devices on the network and seems to allocate a random device to the forwarded ports. If you can get the "missing" device to send traffic through the router, suddenly the router remembers the device and port forwarding start to work again. Well, for a short while until it forgets again.
On these forums I can see that others are having a hard time with this very obviously flawed router, but Plusnet ( [removed]) advises me that a BUSINESS router supplied by Plusnet (for a new customer I recommended ) isn't guaranteed to do anything other than provide an Internet connection. And, I should purchase my own if I'm unhappy about it. By this we can assume that Plusnet doesn't give a hoot whether or not DHCP, DNS, Port Forwarding, etc work as long as it says "connected" on one of its screens. Specifically in my case, it seems inconsequential to Plusnet if I can't use port forwarding to remotely access my internal devices as long as I can Google! Simply woeful. I've been a Plusnet customer for 14 years and it seems the quality of the support has declined significantly over that time. Excerpt of the salient bits of link:csa removed response below

Quote

[removed] - CSC Analyst 8:51am, Wednesday 20 Jan 2016 Dear Mr Husain, Thank you for getting in touch, to rule out the individual router from having a fault I have ordered a replacement for you which should arrive in 3-5 working days. If you still experience the same issue then we would be unable to help further. The router we supply is to provide an internet connection and we do not guarantee other features will suit your business needs. The router also does not form part of your contract with us. If the replacement has the same issue then I can only advise to source an alternate router.

[Moderator's note by Adie (dvorak) csa name removed as per Forum Rules]

[#2]

How did you set the device to have a fixed IP, on the router or by setting the IP on the device to a number outside of the DHCP range?

[#3]

Hi Spoon
The device gets its static external ip automatically. The internal ip is set in the expert_user.html page and we have DHCP is switched off. We have a Windows Server based network and our server does the DHCP and DNS as you would expect. The problem is that the router only allows you to define the port forwarding base on devices it "sees" on the network. I suspect it only sees these devices when they attempt to send data out through the router. You cannot define port forwarding based on IP like every other router i've encountered, rather its only possible based on the MAC address or Netbios name of seen devices.
If the internal device doesnt send traffic for a while, the router forgets the device and the port forwarding fails. It's starts to work again immediately, without intervention, if it suddenly "sees" the internal device again. Others on this forum have had the precise issue and reported it to Plusnet a year ago. Plusnet's support team are currently acting as if this is new news to them - its obviously a flawed Plusnet customization of the Sagemcom router or faulty Sagemcom firmware. I'm resonably sure that if the issue was due to Sagemcom, it would have be fixed ages ago.
The Plusnet response to my query is that although I have signed up for a business service WITH a router, it isnt down to them to ensure the router can adequately provide basic features like port forwarding.
I have personally introduced 32 of my clients and friends to Plusnet over the last 14 years but possibly it's time to call it a day with respect to the referrals. I am in the highly embarrassing position in which I have to explain to a client that although I have convinced him to dump his previous provider and sign with Plusnet, he will now have to purchase a new router because the Plusnet supplied one is has faults that Plusnet have no intention of fixing. My client is a solicitor and I dread the conversation.
mav:quote

[#4]

A dreadful kludge, but could you set a ping -t 192.168.1.254 running on the device to keep the connection alive while you sort this out? (assuming 192.168.1.254 is the router IP)

[#5]

Hi again Spoon
If only it were that simple. The device is a HP managent port (HP call it their ILO port) that is used to manage servers, provide KVM over IP, etc. It talks to the router just once when it boots. Beyond that, it sends no traffic until it has to. No option of running a ping from that port or IP address.
Plusnet should address the issues with the router. How can their position be for me to buy my own because (effectively) they have no intention of fixing it. The complaints go back to a year ago. They know of the issues but are happy to continue to send the faulty routers out.
As bad as BT, TalkTalk and Sky are, I cannot imagine them sending out routers that they know have major faults without looking to address them. I think I will cast my net much wider when looking for an ISP to recommend to my clients. I cant be the only one to notice the decline in the quality of support staff and service since BT took over in 2006 (?).

[#6]

I think ILO can be set to dhcp, it may even be the default.  If so could you set a fixed reservation in the 2704n?

[#7]

He's disabled the DHCP on the router as their server does that (totally normal on a business setup).