Your ISP's DHCP does not function correctly

[modemrouter]

All,
Hoping you can help with this.
I have a Hitron modem in bridge mode and to this I have connected 2 routers, one an Asus 87U and Asus5300. These have been working fine with no issue until yesterday when the 87U had the red internet light. I have reset the router, reset the modem itself, disconnected the 5300 to see if having the 2 connected was the issue, still the issue persists. I thought maybe the 87U was broken. I had a spare 87U and I tried that but still no internet in these router types. The message on both of them is: Your ISP's DHCP does not function correctly. I am using the regular Asus firmware, and it is currently on: .382_50702

I found something on this forum from a post over a year ago, but I am not sure how to implement it on the Asus 87U.

I searched on this forum and someone suggested this worked for them, but I am not sure how to implement this on my router:

"Use
service "restart_wan_if 0"
service "restart_wan_if 1"

the restart_wan_if is essentially a mini reboot of the wan....."

Someone else suggested this as well after the above is done, still I don't know how to add this to the router:

"
So in the spirit of Colin's and Johns helpful input, one could do this:

Create /jffs/scripts/wan_if_restart.sh and add this code to it:
Code:
#!/bin/sh

# restart primary WAN interface if not connected

check_wanup(){

ping -c 1 -W 1 www.google.com >/dev/null

if [ $? -eq 1 ];then
logger "restarting WAN interface $(nvram get wan_primary) via $0"
service "restart_wan_if $(nvram get wan_primary)" >/dev/null
fi

sleep 10

check_wanup

}

check_wanup

Then call it from /jffs/scripts/services-start:

Create or add to /jffs/scripts/services-start
Code:
#!/bin/sh

/jffs/scripts/wan_if_restart.sh # start the WAN checker

Make sure the files are working:
Code:
dos2unix /jffs/scripts/*
chmod a+rx /jffs/scripts/*
This runs continually in the background and checks every 10 seconds if the WAN interface is reported as up.
If not it restarts the interface."

Thank you!

 

[ColinTaylor]

I'm not sure what you mean by " to this I have connected 2 routers". You can only have 1 router connected to a modem. Presumably one of the devices is not configured as a router but an access point, repeater or media bridge.

Regarding your actual problem; have you considered that the message is actually correct? That you have an ISP issue.

 

[modemrouter]

Thanks @ColinTaylor
As I mentioned, I have had this setup for the longest time. The 2 routers are connected to the hitron modem and they've always worked. The hitron is in bridge mode, while the routers are full routers.
They provide 2 separate ips etc...helps with my connection with the kids' stuff...

I am not sure it's an ISP issue since the second router, Asus5300 works fine with no issues. I also disconnected the Asus5300 so that only the 87u is connected just to isolate the issue and the 87u doesn't work. I left the 5300 by itself and it works. I added the 5300 and 87u to the back of the modem and only the 5300 works. Unfortunately, my spare router is also an 87u, that one doesn't work either...

I think the suggestion in the other forum might work to "fix" the 87U, just not sure how to add this to the router since 1) it can't connect to the internet and 2) I am not sure where in the web UI, I need to add all that code.

Thanks,

 

[ColinTaylor]

OK thanks for the explanation about having two IP's. That makes sense even though it's slightly unusual.

Who is your ISP and are you sure they allow you to have more than one IP address? I'm just thinking that something like that is often an additional account option for which you have to pay extra. Maybe they have just realised that you're using two IP addresses and are only paying for one.

The script that you mentioned merely toggles the WAN connection off and on if the router looses connectivity to the internet. You can acheive exactly the same thing manually in the router's GUI by toggling the Internet Connection switch at http://router.asus.com/device-map/internet.asp

 

[Grisu]

disconnect 5300 and plug in 87U only to see if it will work with it as single public IP.

 

[ColinTaylor]

disconnect 5300 and plug in 87U only to see if it will work with it as single public IP.

He said he tried that in both of his posts.

But in a similar vain;

1. Try changing the WAN "DHCP query frequency" from Aggressive to Normal or vice versa.

2. Determine the WAN MAC address of the functioning 5300. Turn off the 5300. On the 87U's WAN setup page set the MAC Clone address to that of the 5300.

If option 2 works then I'd say it's an ISP account issue.

 

[modemrouter]

Thanks, I tried that already and the 87U doesn't work still when I plug it into the same port the 5300 was in.

disconnect 5300 and plug in 87U only to see if it will work with it as single public IP.

 

[modemrouter]

I don't see a WAN MAC address when I go to WAN-->Internet Connection----> Special requirements from ISP- it's blank.
But I do see a LAN MAC, should I use that?

I tried step 1 yesterday. It was in Aggressive and I change it to Normal, no luck.

He said he tried that in both of his posts.

But in a similar vain;

1. Try changing the WAN "DHCP query frequency" from Aggressive to Normal or vice versa.

2. Determine the WAN MAC address of the functioning 5300. Turn off the 5300. On the 87U's WAN setup page set the MAC Clone address to that of the 5300.

If option 2 works then I'd say it's an ISP account issue.

 

[ColinTaylor]

I don't see a WAN MAC address when I go to WAN-->Internet Connection----> Special requirements from ISP- it's blank.
But I do see a LAN MAC, should I use that?

No, best not (even though they might be the same for some bizarre reason - but that's another story ).

Can you enable SSH access on the 5300 and log into it. Then issue this command, it will give you the 5300's MAC address.

# nvram get wan0_hwaddr
30:5A:3A:C7:8A:20

 

[modemrouter]

I don't know how to enable SSH access

 

[Datalink]

@modemrouter after you have run the routers one at a time, plug the second router back into the modem and restart the modem. Pull the power off of the modem, wait for 10 to 15 seconds and plug the modem back in. Hopefully that will result in both routers running with their usual independent IP addresses after the modem reboot is complete. Sometimes you have to do this routine, get one router working, then swap the routers and get the second one working, and then plug both of them into the modem and reboot/restart the modem.

Are you with Rogers Communications, in Canada by chance?

Just to expand on the previous explanation, Rogers Hitron modems are Gateway devices, capable of running in a Gateway (router) mode, and a Bridge (modem) mode. The modems have four ethernet ports. In Bridge mode, all four ethernet ports are active and will provide the first two devices with both IPV4 and IPV6 addresses. The following two devices will only receive IPV6 addresses. In Bridge mode, the modem is just a modem, no firewall, DHCP Wifi, etc, etc.

@modemrouter if you happen to be with Shaw Communications, call their tech support. They use a pass-through scheme of some type that can only be authorized by them to allow for a second device to be plugged into the modem. Maybe something has gone wrong with that pass-through authorization, and has nothing to do with the routers themselves.

 

[Grisu]

I don't know how to enable SSH access

Its very easy done nowadays:
enable SSH access on router admin page
open Windows 10 (last1809 release) PowerShell as admin and type:
ssh your_router_user@your_modem_IP_address (e.g. ssh 86Uadmin@192.168.1.1)
now password is asked, type it (will not be shown)
and you are connected, same as telnet but with SSH connection

Now type from above:
nvram get wan0_hwaddr

 

[modemrouter]

Thanks @Datalink,
So, it's interesting that the 87U worked when I powered off the modem (when I disconnected the 5300 from the modem) and powered the modem back on. Up until now, the 87U didn't work when I reset just the router on it's own, but powering down the modem while the 87u was connected (and the other disconnected) now that router is online. But when I plugged the 5300 into the modem while the 87u was connected, now the 5300 is no longer online.
@ColinTaylor, you were right, it must be my ISP. I called them earlier in the day asking if they messed with my connection and they assured me they didn't. But it must be something on their end, because it's not the routers that are broken.
@Datalink, I am not in Canada, so not on Rogers or Shaw. I have been using the wrong terminology, the Hitron must be on Gateway mode as you described since I was able to use the 2 routers at the same time.
I guess I will call them again about the pass-through scheme, and I hope I find someone who is competent on the line and can assist. The person I spoke to earlier, had no clue.
Is there anything else I can do? Is there a DHCP setting on the Hitron that I adjust that will now make this work?
Thanks again guys.

 

[modemrouter]

Thanks Grisu,
What if I am using a mac computer?

Its very easy done nowadays:
enable SSH access on router admin page
open Windows 10 (last1809 release) PowerShell as admin and type:
ssh your_router_user@your_modem_IP_address (e.g. ssh 86Uadmin@192.168.1.1)
now password is asked, type it (will not be shown)
and you are connected, same as telnet but with SSH connection

Now type from above:
nvram get wan0_hwaddr

 

[Grisu]

ask a friend for a Win machine or aks Steve Jobs and whats if you use a Linux computer?
Or wait for someone else who knows how to do!
Think its very similar ... sorry dont have a Mac.

 

[Datalink]

@modemrouter you would have to be sure of which mode the modem is running in. In Gateway mode, the routers would have an IP address that is within the modems IP address range. You would be able to connect a third and/or forth device to the modem and they would receive their own respective LAN IP addresses. You would be able to recognize all of the addresses as being in the modem's LAN IP address range, essentially confirming that modem was in Gateway mode.

If the modem was in Bridge mode, then each router would have its own WAN IP address. You should be able to recognize the WAN IP address range.

If the modem was running previously in Bridge mode and you had done nothing with your equipment, then I would conclude that there must have been some change with the CMTS configuration. You would probably have to get beyond first line tech support to get any real answers as to what might have occurred with the CMTS.

Was there a modem firmware update by any chance? If so, you should reboot the modem at the very least. I'd suggest running a modem factory reset, with or without any possibility of a firmware update. At this point, I don't think that you have anything to lose in carrying out a factory reset.

You should call your tech support to clarify the modem's Bridge mode device limitations. Does your ISP support multiple devices connected to the modem when the modem is operating in Bridge mode? Each ISP is different in what they will allow. Most likely this will come down to the availability of IPV4 addresses for your ISP and whether or not your ISP is generous enough to permit multiple IPV4 addresses for its customers. If multiple devices are supported, does the user have the ability to just plug and play, or does this require special pass-through settings that only tech support can do?

 

[modemrouter]

Thanks @Datalink I will revert back tomorrow after I contact my ISP.
I'll also log into the modem to confirm exactly if I am on gateway or bridge mode. I am unable to connect to the internet through the modem in the current mode I am in, I only connect to the internet through the 2 routers.

This setup was working before and we didn't mess with it. So, it's very likely that the ISP did some update on the backend, but I didn't do any firmware upgrade on the modem or routers.

Thanks!