Spontaneous DHCP failure
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Hello
Sometimes the DHCP stops working on the pfsense server, and in an instant all the hosts connected by DHCP lose communication and when connecting new devices to a wireless network it does not work through DHCP, only through static IP (I have only been able to solve it by restarting pfsense but the problem returns.), I also have several servers configured on the DNS Forwarder and when I try to access them on a PC connected by DHCP sometimes the name cannot be resolved.
Thanks for any help, if needed, more details will be pending.
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@ejimenez03 said in Spontaneous DHCP failure:
Sometimes the DHCP stops working on the pfsense server, and in an instant all the hosts connected by DHCP lose communication
When I stop / kill / dsiable my DHCPv4 server on pfSEnse, traffic still flows, no network issues what so ever.
Leases are valid for hours (why that short, make them longer if you can / feel the need) or even days. The LAN connected devices will renew eventually, and that might fail, with known consequences.What your are saying, indirecly, is : the network 'cable' called LAN fails. I could be the cable, the NIC on the pfSense side, or the switch on the other side.
So the pfSEnse NIC goes down, and "attached" services like DHCPv4 server will bail out.
Network connections on the LAN connected devices will also stop right away.These events are of course logged in the ....... logs.
If the network goes down, DNS, like everything else, will fail of course.
Can't tell what will happens with unbound, the resolver, when you pull out one of the attached interface. It probable will stop / fail also. -
@ejimenez03 as @Gertjan was saying dhcp running has little to do with clients that already have an IP from dhcp from working.. The only thing that dhcp not running would prevent is clients who lease actually expired, or new clients that don't have an IP.
I believe the default lease is like 2 hours.. So in any typical setup where clients renew at the 50% mark - the worse case scenario is you could run for an hour before clients start having issues with renewing their lease.. And once it fully expires then yeah they would stop using the IP they got from dhcp and fail.
I have my lease at 4 days.. There is little reason for clients to constantly renew every hour in my network. If I made some change in dhcp setting that I would want clients to get, then I would renew their leases on the device, by either a reboot or command.
You prob have something else causing your network issue, and dhcp stopping is just a symptom of that other problem.. As suggested have a full look into your log to what that might be.
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@Gertjan @johnpoz Thank you both for your responses. I haven't been able to view the logs when the network goes down due to restarting the server and restoring the network as quickly as possible. I will do it if the network goes down again.
A recurring message I have seen in the logs is that the MAC address fluctuates. I have virtualized pfSense on a Proxmox server with 2 network interfaces with static IPs. Interface 1: IP1 and Interface 2: IP2, each with its own MAC address. For example, Interface 1: xx:xx:xx:xx:xx:m1 and Interface 2: xx:xx:xx:xx:xx:m2. The logs show me the following message:
"Nov 1 07:25:25 kernel arp: IP1 moved from xx:xx:xx:xx:xx:m1 to xx:xx:xx:xx:xx:m2 on em1
Nov 1 07:25:30 kernel arp: IP1 moved from xx:xx:xx:xx:xx:m2 to xx:xx:xx:xx:xx:m1 on em1
Nov 1 08:35:25 kernel arp: IP1 moved from xx:xx:xx:xx:xx:m1 to xx:xx:xx:xx:xx:m2 on em1
Nov 1 08:35:30 kernel arp: IP1 moved from xx:xx:xx:xx:xx:m2 to xx:xx:xx:xx:xx:m1 on em1"This happens with the Proxmox server and my PC only, the other hosts do not have this problem. Could it be a symptom of the previous issue? Could it be a hardware problem with the NIC?
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@ejimenez03 well if your mac is moving to different interfaces because your pfsense is a VM, then yeah that could all kinds of issues with your network..
