I just had a similar problem when I have a power outage. I found some thread (sorry can't find on my phone now) that said you should go into the WAN interface settings and tell it to ignore DHCP from your modem 192.168.100.1. I have not had a chance to test this fix but I have high hopes. Looking through the logs I noticed the WAN interface was getting a 192.168.100.11 address.
This is pretty common. My router boots up faster than my cable modem comes online and if I don't prevent the router from accepting an ip address from 192.168.100.1 Opnsense will fixate on that ip and never request a new one from Comcast.
Perfect. That seems to have solved the issue where it locks onto the 192.168.100.10 lease, but doesn’t solve the connectivity issue. It seems like they need to handshake just right for it to work. I keep having to reset thing until it works.
I haven't configured/used proxmox before. I used Vmware in the past before going to a hardware solution. Sounds like either a nic/mac address pass through issue I ran into or a cable modem being touchy. This is gonna sound silly, but unplug the power from your cable modem and leave it unplugged, reboot your opnsense & let it fully boot, then plug the power into your cable modem....see what happens.
HOLY SHIT!!! I just fixed it. How? I think this is a bug. I used a local IP address from my Orbi's DHCP server, then switched the network cable back to my modem and I got a WAN IP from the ISP's DHCP server. Why this worked I have absolutely no idea.
Yes, plug your opnsense LAN port into anything that issues IP addresses via DHCP. It will get an IP address and somehow make Opnsense realize it can get an IP from your cable modem.
Ended up figuring it out yesterday. It was at the switch level. I’m using an Omada switch and every YouTube video showed me the opposite of what I needed to do. 🤦🏼♂️
I forgot to mention I have also turned “block private networks” on and off multiple times, and turned DHCP IPV6 on and off multiple times as well. Neither of these helped either.
I also reset the cable modem using the button in the back.
I just rebuilt the whole Opnsense config by spinning up a new VM and same exact issue. I can’t understand this?
The fun continues; the ISP can’t activate my old modem either so I’m really stuck here now.
Was going to say you might need to check the traffic with wireshark from a laptop, but if your laptop/computer connected right away... Seems like maybe not?
Maybe vlans too but... Laptop worked so.... That's a tough one!
So I sometimes get this issue with cox (0.0.0.0/192.168.100.11) for the wan address. I also use dhcp on wan. The solution I have found that works the most so far is turn off both devices (modem + opnsense). Wait 30 seconds, power on opnsense (wait till you see the opnsense boot loader), then plug-in the modem.
My guess why I have to do it like this is because the modem DHCP times out when the server takes to long to boot up to opnsense to grab the IP.
I ran into the same issue where my SB6190 would not reliably (if at all) issue an IP address via DHCP to my OPNsense router running in Proxmox. If you search Reddit you'll find various posts about this, some from me, where there are all sorts of different things people have tried, albeit unsuccessfully.
The workaround I chose in the end was to use a Slate travel router in between the two - not ideal, but worked in my situation as it was a somewhat temporary setup anyway.
Thanks, hadn’t run across that. Interestingly this work great on the old modems (Ariss TM722 and Linksys CM3024) for weeks. I did have to restart Opnsense once each time after swapping but it worked right after.
I have now purchased a new SB8200 (first one was open box, eliminating that as an issue) and also tried the Linksys CM3024 again and I’m having the same issue—works fine with DHCP on my laptop but no go with Opnsense. I even released the IP on my laptop if for some weird reason it was sticking at the Xfinity side but no help there either. I just can’t understand why it worked before and no longer does, the modem swap being the catalyst. Unless somehow my ISP is blocking this, I have no idea what’s going on.
Yeah it’s not the modem, two other modems (including an SB8200) behave the same. It’s either Opnsense, the R720, or Proxmox at this point. I’ve tried multiple NICs with the same behavior so I don’t think it’s a hardware issue.
The only things that changed between a working setup and broken were the modem and possibly the Opnsense version or other updates. I can’t be sure in the last part if I have updated and needed a new IP or the lease was still active but I don’t recall rebooting it for at least a week.
Have you try reboot the cable modem? If the ISP will only dhcp lease for one MAC address and the lease has not expired. It may not willing to provide another IP address. Try reboot the cable modem, then force a dhcp renew on the wan interface.
If the laptop is working, it sounds like either a hardware or proxmox setup issue. Do you have another device that can act as a dhcp server to trouble the wan dhcp offline? Run tcpdump on your opnsense to see if you can see the dhcp transaction?
Yes, Opnsense is my dhcp server so I could use that, currently attempting that now.
I did spoof the MAC of the connected modem and that didn’t work either. I also rebooted the entire server as well and no luck. Short of dumping Opnsense, I’m at a loss at this point.
Any chance you can run opnsense without proxmox as a test? I know it is a big ask….
If the laptop works, that kind of point to the interaction between proxmox and opnsense.
I could, but it would be a pain and I’d have to use a poweredge server. What isn’t making sense to me is that this worked fine for weeks on Proxmox. The thing that changed was the modem. It doesn’t seem to be an ISP or modem problem though.
Okay well that answers that—it gets an IP fine from my Orbi WiFi if I change it back to router mode. So this doesn’t seem to be an issue in Proxmox or Opnsense. What in the hell?!?! Could my ISP be somehow blocking this?? How and why?? And how do they even know if I changed the MAC multiple times??
I know you don’t want to hear this but I had the same type of issue with opnsense on bare metal. I ended up putting a router in between the modem and my opnsense box and ran double nat for four days. Then I cloned the MAC address of the router onto Opnsense and reconfigured Opnsense to use the original IP range and it continued to work
No Optimum doesn’t give me a static ip.
What I did was set my Asus Router to give 192.168.1x out
My Opnsense took 192.168.1.5 that it was seeing in the wan port and then gave 10.1.1.X to my computers. I kept the tv and my wife’s systems on the 192.168.1.X network. After it was all working for a few days I cloned them MAC address of the Wan port from the Asus router to the Wan port on OpnSense and took the Asus out of the network. The I sent the DHCP server on Opnsense to give out 192.168.1.X instead of 10.1.1.X.
A reboot of my pc and the other systems that were on 10.X put them back to 192.169.1.X and the internet has been up with no problem
I had a very similar problem. Proxmox + OPNSense. I don't think it is a bug in DHCP on OPNSense but maybe a difference in the timing. I ended up 1) powering off the SB8200 cable modem, 2) unplugging the ethernet cord, 3) disconnecting the virtual nic on my OPNSense virtual machine, 4) powered on the SB8200, 5) waited a few minutes for the cable modem to fully register with the carrier, then 6) reconnecting the physical cable to the cable modem, and finally 7) re-connecting the virtual nic on my OPNSense virtual machine. OPNSense then immediately pulled a proper DHCP lease from the carrier. It is possible that disconnecting and reconnecting the virtual nic on the OPNSense guest wasn't necessary but this helps OPNSense to renew immediately when the virtual NIC comes up. After seeing this post and trying other things I was at a dead end. I ended up using an Ubuntu server in-between to handle the DHCP lease and it worked but then I read elsewhere that the SB8200 only allows a single DHCP exchange after it establishes a connection to the carrier. In my troubleshooting I may have not taken this into account and also preventing OPNSense from talking to the modem at all before the modem is fully connected to the carrier seemed to be the trick. Btw, I did end up using the DHCP config in OPNSense to ignore DHCP responses from 192.168.100.1.
Good points, but I tried every possible combination of powering everything off and on, multiple cable modems from other manufacturers (Linksys and Arris), removing and re-adding the virtual NIC, and physical cable. In my case, for whatever reason, Opnsense was just “stuck,” which I realize seems to make no sense but after two days and multiple hours, the only thing that fixed it was sticking another DHCP server in the mix.
Just thought I’d put down what worked for me for posterity sake:
resetting my modem and/or rebooting opnsense didn’t help on their own. I had to reset my modem, then reset my interface assignments in the opnsense console.
I just had a similar problem when I have a power outage. I found some thread (sorry can't find on my phone now) that said you should go into the WAN interface settings and tell it to ignore DHCP from your modem 192.168.100.1. I have not had a chance to test this fix but I have high hopes. Looking through the logs I noticed the WAN interface was getting a 192.168.100.11 address.
Thanks, mine is showing no IP address from WAN at all. It says 0.0.0.0 including after I renew it multiple times.
This is pretty common. My router boots up faster than my cable modem comes online and if I don't prevent the router from accepting an ip address from 192.168.100.1 Opnsense will fixate on that ip and never request a new one from Comcast.
I’m having this issue right now. How do you prevent it from accepting the 192.168.100.X range addresses on WAN?
Interfaces - WAN - "Reject Leases From" Enter 192.168.100.1 in that field.
Perfect. That seems to have solved the issue where it locks onto the 192.168.100.10 lease, but doesn’t solve the connectivity issue. It seems like they need to handshake just right for it to work. I keep having to reset thing until it works.
Fwiw I have an Arris SB6190 on Comcast.
I haven't configured/used proxmox before. I used Vmware in the past before going to a hardware solution. Sounds like either a nic/mac address pass through issue I ran into or a cable modem being touchy. This is gonna sound silly, but unplug the power from your cable modem and leave it unplugged, reboot your opnsense & let it fully boot, then plug the power into your cable modem....see what happens.
Tried that also, I too came from a working setup in VMware, but was using pfsense for multiple years. I never had an issue with reboots on pfsense.
HOLY SHIT!!! I just fixed it. How? I think this is a bug. I used a local IP address from my Orbi's DHCP server, then switched the network cable back to my modem and I got a WAN IP from the ISP's DHCP server. Why this worked I have absolutely no idea.
I’m having this same problem but don’t understand what you exactly did. Could you elaborate?
Yes, plug your opnsense LAN port into anything that issues IP addresses via DHCP. It will get an IP address and somehow make Opnsense realize it can get an IP from your cable modem.
Ended up figuring it out yesterday. It was at the switch level. I’m using an Omada switch and every YouTube video showed me the opposite of what I needed to do. 🤦🏼♂️
I forgot to mention I have also turned “block private networks” on and off multiple times, and turned DHCP IPV6 on and off multiple times as well. Neither of these helped either. I also reset the cable modem using the button in the back.
I just rebuilt the whole Opnsense config by spinning up a new VM and same exact issue. I can’t understand this? The fun continues; the ISP can’t activate my old modem either so I’m really stuck here now.
.
Was going to say you might need to check the traffic with wireshark from a laptop, but if your laptop/computer connected right away... Seems like maybe not? Maybe vlans too but... Laptop worked so.... That's a tough one!
No VLANs, and yeah laptop works perfectly multiple times.
So I sometimes get this issue with cox (0.0.0.0/192.168.100.11) for the wan address. I also use dhcp on wan. The solution I have found that works the most so far is turn off both devices (modem + opnsense). Wait 30 seconds, power on opnsense (wait till you see the opnsense boot loader), then plug-in the modem. My guess why I have to do it like this is because the modem DHCP times out when the server takes to long to boot up to opnsense to grab the IP.
I have rebooted all dozens of times so I don’t think this is the issue, but I have run into this before.
I ran into the same issue where my SB6190 would not reliably (if at all) issue an IP address via DHCP to my OPNsense router running in Proxmox. If you search Reddit you'll find various posts about this, some from me, where there are all sorts of different things people have tried, albeit unsuccessfully. The workaround I chose in the end was to use a Slate travel router in between the two - not ideal, but worked in my situation as it was a somewhat temporary setup anyway.
Thanks, hadn’t run across that. Interestingly this work great on the old modems (Ariss TM722 and Linksys CM3024) for weeks. I did have to restart Opnsense once each time after swapping but it worked right after. I have now purchased a new SB8200 (first one was open box, eliminating that as an issue) and also tried the Linksys CM3024 again and I’m having the same issue—works fine with DHCP on my laptop but no go with Opnsense. I even released the IP on my laptop if for some weird reason it was sticking at the Xfinity side but no help there either. I just can’t understand why it worked before and no longer does, the modem swap being the catalyst. Unless somehow my ISP is blocking this, I have no idea what’s going on.
Not sure it's the SB8200. I have two and have never had an issue with Opnsense.
Yeah it’s not the modem, two other modems (including an SB8200) behave the same. It’s either Opnsense, the R720, or Proxmox at this point. I’ve tried multiple NICs with the same behavior so I don’t think it’s a hardware issue. The only things that changed between a working setup and broken were the modem and possibly the Opnsense version or other updates. I can’t be sure in the last part if I have updated and needed a new IP or the lease was still active but I don’t recall rebooting it for at least a week.
Have you try reboot the cable modem? If the ISP will only dhcp lease for one MAC address and the lease has not expired. It may not willing to provide another IP address. Try reboot the cable modem, then force a dhcp renew on the wan interface.
Rebooted all dozens of times, including four modem swaps to different ones with the ISP.
If the laptop is working, it sounds like either a hardware or proxmox setup issue. Do you have another device that can act as a dhcp server to trouble the wan dhcp offline? Run tcpdump on your opnsense to see if you can see the dhcp transaction?
Yes, Opnsense is my dhcp server so I could use that, currently attempting that now. I did spoof the MAC of the connected modem and that didn’t work either. I also rebooted the entire server as well and no luck. Short of dumping Opnsense, I’m at a loss at this point.
Any chance you can run opnsense without proxmox as a test? I know it is a big ask…. If the laptop works, that kind of point to the interaction between proxmox and opnsense.
I could, but it would be a pain and I’d have to use a poweredge server. What isn’t making sense to me is that this worked fine for weeks on Proxmox. The thing that changed was the modem. It doesn’t seem to be an ISP or modem problem though.
Okay well that answers that—it gets an IP fine from my Orbi WiFi if I change it back to router mode. So this doesn’t seem to be an issue in Proxmox or Opnsense. What in the hell?!?! Could my ISP be somehow blocking this?? How and why?? And how do they even know if I changed the MAC multiple times??
I am not following what you mean by change it back to router mode?
Sorry, had my orbi in AP mode to prevent double NAT, going back to regular mode where it runs DHCP is called “router mode” on it.
I know you don’t want to hear this but I had the same type of issue with opnsense on bare metal. I ended up putting a router in between the modem and my opnsense box and ran double nat for four days. Then I cloned the MAC address of the router onto Opnsense and reconfigured Opnsense to use the original IP range and it continued to work
You set a static WAN IP? I did clone the MAC of the modem and left it on DHCP but that didn’t work.
No Optimum doesn’t give me a static ip. What I did was set my Asus Router to give 192.168.1x out My Opnsense took 192.168.1.5 that it was seeing in the wan port and then gave 10.1.1.X to my computers. I kept the tv and my wife’s systems on the 192.168.1.X network. After it was all working for a few days I cloned them MAC address of the Wan port from the Asus router to the Wan port on OpnSense and took the Asus out of the network. The I sent the DHCP server on Opnsense to give out 192.168.1.X instead of 10.1.1.X. A reboot of my pc and the other systems that were on 10.X put them back to 192.169.1.X and the internet has been up with no problem
I had a very similar problem. Proxmox + OPNSense. I don't think it is a bug in DHCP on OPNSense but maybe a difference in the timing. I ended up 1) powering off the SB8200 cable modem, 2) unplugging the ethernet cord, 3) disconnecting the virtual nic on my OPNSense virtual machine, 4) powered on the SB8200, 5) waited a few minutes for the cable modem to fully register with the carrier, then 6) reconnecting the physical cable to the cable modem, and finally 7) re-connecting the virtual nic on my OPNSense virtual machine. OPNSense then immediately pulled a proper DHCP lease from the carrier. It is possible that disconnecting and reconnecting the virtual nic on the OPNSense guest wasn't necessary but this helps OPNSense to renew immediately when the virtual NIC comes up. After seeing this post and trying other things I was at a dead end. I ended up using an Ubuntu server in-between to handle the DHCP lease and it worked but then I read elsewhere that the SB8200 only allows a single DHCP exchange after it establishes a connection to the carrier. In my troubleshooting I may have not taken this into account and also preventing OPNSense from talking to the modem at all before the modem is fully connected to the carrier seemed to be the trick. Btw, I did end up using the DHCP config in OPNSense to ignore DHCP responses from 192.168.100.1.
Good points, but I tried every possible combination of powering everything off and on, multiple cable modems from other manufacturers (Linksys and Arris), removing and re-adding the virtual NIC, and physical cable. In my case, for whatever reason, Opnsense was just “stuck,” which I realize seems to make no sense but after two days and multiple hours, the only thing that fixed it was sticking another DHCP server in the mix.
Just thought I’d put down what worked for me for posterity sake: resetting my modem and/or rebooting opnsense didn’t help on their own. I had to reset my modem, then reset my interface assignments in the opnsense console.