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Sagemcom F@ST™ 3864V3AC Static IP page missing


Hi everyone,


I have a Sagemcom F@ST 3864V3AC NBN modem and I'm trying to setup some static IP's on my network. Problem is, when I go to the 'Advanced Setup' -> 'lan' page and click on 'Add Entries' under the 'Statip IP lease list' I get a blank page, just the menu down the left hand side. Also happens if I try clicking on the button on the 'Advanced Setup' page as you can see it there also.


I've tried resetting the modem which didn't help. My googling has also failed to find any similar issues or anything useful. I rang Optus help but that was a joke, "we don't support these advanced features". The support person then helpfully suggested she could connect me to Sagemcom support which resulted in me being cut off after waiting on the line for 15 minutes. Queue some foul language and a mobile almost sailing across the room!

Anyway, I'd appreciate any suggestions as to what's going on here?




Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


I have been trying to find a solution to this problem for a while now. It seems that when you click the "add entries" button it executes some Javascript that redirects to another page. This page is "StaticIpAdd.html", but for some reason the page is completely empty. I guess the developers forgot to include the implementation of static IP allocation in this software revision ¯\_(ツ)_/¯.


However, after some more probing I figured out a work around that will let you add an entry to the static IP list, but it is quite involved. Basically, you have to use the following URL to execute the static IP lease. ROUTER_IP/dhcpdstaticlease.cmd?action=add&mac=MAC_ADDRESS&static_ip=IP_YOU_WANT&sessionKey=KEY. So you have to find the MAC address of the device you want to allocate the static IP to, then determine the IP you want to allocate to it, and finally determine the session key. Unfortunately the session key seems completely random and is generated on every request sent to the router, but on the up side the key is written in plain text within the webpage. You can find it by locating the Javascript code that it is written in (it is a Javascript variable named sessionKey) on the advanced setup -> LAN page, or you can execute some code I will attach below that I wrote to isolate it. You can achieve this by opening the developer console (hit F12 in most browsers) on the router's webpage and entering the Javascript code in the console section. Once you have the session key, just include it. Here is an example URL;


Hopefully this isn't too convoluted and you can make some sense of it, I just wish the developers had completed their development to include the GUI side of static allocation. Any questions regarding my explanation, please ask. Also, the static allocation will apply once the router is rebooted.

Code to isolate session key (enter in developer console when on advanced setup -> LAN webpage):
q = s.substr(s.indexOf("sessionKey"))
q.substr(0, q.indexOf("\n"))

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


Vigi, you bloody legend!!!


This worked perfectly! Thank you so much for taking the time to post this and for what I'm sure was many hours of poking around to figure this out. How a half finished product gets shipped like this I'll never understand ¯\_(ツ)_/¯.

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


Amazing. It worked! Let's hope for a firmware update that turns this into an actual finished product!

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


OPTUS!!! Please get a firmware update to us or send us functioning f'ing routers in the first place!!!!!  I just got this router after a week of down time as the last one failed. You send me a new one and I am unable to set up my printer/scanner with a fixed IP on my subnet!! OPTUS is the worst NBN provider. They do not call a customer with issues back and I spent over 2 hours with their overseas support team that were clueless the last time I attempeted to get assistance.

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


This worked but I am till not happy that this level of technical expertise is required to use a modem supplied to average consumers!!

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


I created an account just to say thank you for doing this awesome troubleshooting, then posting for us! Optus techs- this needs sorting out with a patch. Not sure how it passed QA.

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


thanks for your efforts

but its seems to work but popping with an error conflict


"DHCP Static IP Lease Error
The Broadband Router cannot add the new static IP lease since either the Mac address or the IP address conflict with previous rules. 
Click on "Back" button to try another static IP configuration. "


there are no rules or ip conflicts that are configured so not sure if this is another bug

please let me know if there is some trick to this issue

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


Thanks mate - that worked a treat - Optus Support should be paying you!

Re: Sagemcom F@ST™ 3864V3AC Static IP page missing


Awesome.  I could not get the code to get the sesssion key to work in chrome, however the session key was in plain site as a variable declaration when I view the file in F12 Dev Tools.




Also the created command e.g. to be set in a new tab address bar Which was not immediately obvious (to me).


Great work.

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