Strange DHCP issue. Assigned /8 instead /24 on Linux devices.
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@kiokoman today i checked all once again, and i see that the 255.0.0.0 mask was assign to windows machines too, but in settings of DHCP server (and lan interface too) installed a 255.255.255.0 mask... How that work?
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if you can plug something directly to the lan of pfsense to see if it works, maybe there is something wrong on the switch
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You probably have another DHCP server on your network.
Packet capture the port 67 traffic and wireshark will tell you exactly what DHCP is doing. Pay close attention to what MAC address is sending what.
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@kiokoman i'm tied, nothing changes...
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@Derelict said in Strange DHCP issue. Assigned /8 instead /24 on Linux devices.:
Packet capture the port 67 traffic and wireshark will tell you exactly what DHCP is doing.
Tried it too. PFSense is only the one dhcp server in the my network... :(
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You don't have anything configured under "Additional BOOTP/DHCP Options" do you?
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Post the packet capture of a complete DHCP exchange. If the DHCP server is sending /24 and the clients are setting /8 there is nothing the DHCP server can do about it.
Also post the contents of /var/dhcpd/etc/dhcpd.conf from the pfSense node.
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@Derelict
wireshark capture: (deleted)dhcp.conf (deleted)
I cleared private data from dhcp.conf
@chpalmer nothing in Additional settings.
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Go back into the settings of your padavan units and verify that the DHCP servers are truly turned off.
Go into your switches and verify that the DCHP servers are truly turned off.
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@chpalmer shure, it's already done...
No active DHCP servers on my padavan units (configured as access points), switches (it's not have a dhcp server options), and on my synology unit too... -
I confused the DGS1100 and the DGS1510 which does have an available DHCP server..
On the Padavan there is the option of Static IP assignment.. Is that also off?
Are all your Linux devices you are testing wireless?
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@chpalmer said in Strange DHCP issue. Assigned /8 instead /24 on Linux devices.:
all your Linux devices you are testing wireless?
It's not have anything about DHCP or address reservations. Configured as access point. Another padavan unit configured the same.I tested wireless and wired devices, nothing changes, but today i see that the windows device assigned 255.0.0.0 too. So, it's not a linux problem...
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Quick test.. Unplug everything from your pfSense router. Or just turn it off.
Reboot one of the devices that is getting wrong info. See if it gets an address.
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@chpalmer tried it before, and it's not help, but, i will try it tomorrow again...
Pfsense unit not in my room, and for now i can't access it phisicaly. -
@lazy said in Strange DHCP issue. Assigned /8 instead /24 on Linux devices.:
wireshark capture: bootpwireshark.pcapng
I don't see option 1, the subnet mask in there.
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Sorry guys, totally my bad :(
I'm not fully understand how works Additional DHCP settings in pfsense...
At very strange situation, I have option "1" in Additional DHCP settings with parameter "text", and under this table was button "add", I think I need to push this button for take effect....
I'm totally don't know how "1" was typed here, maybe my mistake (missclick), maybe something else...
I removed "1" from the option, and then the correct mask was successfully assigned to my devices...I really want to make a death facepalm to myself.
@chpalmer you was right!
@JKnott thank you, I think I don't take attention to this parameter without your comment.
Also, I deleted my dump and other files that may have my personal data.
Thanks to all. This theme may be closed, and marked as solved.
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@lazy said in Strange DHCP issue. Assigned /8 instead /24 on Linux devices.:
When I connect any Linux based device (Debian, Ubuntu, Synology, Android, etc), I have assign a wrong DHCP settings with Network mask 255.0.0.0, and can't use Network on some devices (Android and Synology works, but any of Linux distro won't works).
One thing on this, back in the classfull subnet days, a 10.0.0.0 network was a class A network, with a /8 subnet mask. It appears Linux is following that convention. I have no idea why other devices are doing otherwise.
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@JKnott I have no idea too...
All Linux devices was followed this rules, but windows devices are followed too, but not all.
I have 3 Windows 10 devices with assigned /8 in this situation, and all other devices was assigned /24 in this situation.
But now all works well, I fixed this issue by removing Aditional DHCP settings, as i told before.Thanks again!
