TheLazyIT
Posts: 10
Joined: Tue Mar 26, 2019 2:11 am

Configure PiServer Tool to Listen on Multiple Interfaces??

Mon Jan 20, 2020 2:32 pm

Hello,

I set up the PiServer tool on a VM and configured it to act as DHCP relay, but I need it to boot clients from multiple subnets. I attempted to set up an ip helper, but I have been unsuccessful in getting it to work on any subnet other than the one the PiServer tool is on. With that in mind, is it possible to configure it to listen on multiple interfaces if I add a NIC on a different subnet? I know it's not possible in the GUI, but I am hoping I could change some settings on the backend to get it to work. Thank you.

incognitum
Posts: 427
Joined: Tue Oct 30, 2018 3:34 pm

Re: Configure PiServer Tool to Listen on Multiple Interfaces??

Tue Jan 21, 2020 9:42 am

TheLazyIT wrote:
Mon Jan 20, 2020 2:32 pm
I set up the PiServer tool on a VM and configured it to act as DHCP relay,
I assume you configured piserver as proxy dhcp.
DHCP relay = broadcast forwarding = ip helper-address
So something else.
I attempted to set up an ip helper, but I have been unsuccessful in getting it to work on any subnet other than the one the PiServer tool is on.
Suggest you debug that first.
As there is very little that can go wrong with that, and if it does, it usually means your network configuration is screwed up in other ways.

Routing does work correctly, as in from the cli of the Ethernet switch on which you configued ip-helper you can ping piserver ip?

Does the main dhcp server handing out the IPs also live in a foreign vlan?
If so make sure you add both the main dhcp ip and piserver ip as ip helper-address.

Triple check stp is disabled or at least set to portfast flavor on switch ports connecting Pi.

TheLazyIT
Posts: 10
Joined: Tue Mar 26, 2019 2:11 am

Re: Configure PiServer Tool to Listen on Multiple Interfaces??

Thu Jan 23, 2020 1:58 pm

incognitum wrote:
Tue Jan 21, 2020 9:42 am
TheLazyIT wrote:
Mon Jan 20, 2020 2:32 pm
I set up the PiServer tool on a VM and configured it to act as DHCP relay,
I assume you configured piserver as proxy dhcp.
DHCP relay = broadcast forwarding = ip helper-address
So something else.
I attempted to set up an ip helper, but I have been unsuccessful in getting it to work on any subnet other than the one the PiServer tool is on.
Suggest you debug that first.
As there is very little that can go wrong with that, and if it does, it usually means your network configuration is screwed up in other ways.

Routing does work correctly, as in from the cli of the Ethernet switch on which you configued ip-helper you can ping piserver ip?

Does the main dhcp server handing out the IPs also live in a foreign vlan?
If so make sure you add both the main dhcp ip and piserver ip as ip helper-address.

Triple check stp is disabled or at least set to portfast flavor on switch ports connecting Pi.
Thank you for your insight. I was able to resolve this and found a few things that may have contributed.

1. I had my IP helper set correctly, but I discovered that the VLAN I was using for clients was not allowed on the trunk for my VMware hosts.
2. Option 66 was not configured in the Windows DHCP server (this also explains a separate issue I was having with Windows Deployment Services also not working outside of the WDS server's subnet)
3. Lastly, I found that the way PiServer works out of the box limits its functionality. I found a patch on github to fix this along with a few threads from the official PiServer github development page that helped me understand what was going on. They are:

https://github.com/Lukanite/PiServer-PX ... lator/wiki
https://github.com/raspberrypi/piserver/issues/26
https://github.com/raspberrypi/piserver/issues/74

Thank you again.

incognitum
Posts: 427
Joined: Tue Oct 30, 2018 3:34 pm

Re: Configure PiServer Tool to Listen on Multiple Interfaces??

Thu Jan 23, 2020 4:05 pm

TheLazyIT wrote:
Thu Jan 23, 2020 1:58 pm
3. Lastly, I found that the way PiServer works out of the box limits its functionality. I found a patch on github to fix this along with a few threads from the official PiServer github development page that helped me understand what was going on. They are:
Ah, yes.
You are right.

Should have Pi 4 with TFTP_PREFIX=2 setting to be able to use proxy dhcp mode with multiple VLANs.
(Does work in standalone DHCP mode with multiple VLANs and ip-helper since dnsmasq in that case does know which IP belongs to which MAC)
2. Option 66 was not configured in the Windows DHCP server
Should not be necessary for that option to be set if DHCP requests are relayed correctly to Piserver.
You typically set options like that when you want to use the main DHCP server to tell clients to go to the tftp server, and do not have a proxy dhcp server that does that.

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