In DHCP configuration, DHCP start IP and DHCP End IP should be allowed. We use this setup a lot for customer with a static IP adresse, route a /30 and give the customer a single IP address in DHCP so the setup is plug-and-play for the customer instead of having to configure is router manually.
Thanks
Hi Michel,
I think this is a good idea so I've moved your post to the Your Ideas section, where the Cambium development team can consider it.
Thanks,
Alex
I was thinking of it more like a wrong GUI behavior since I never saw a DHCP server not supporting a single address (at less, not a commercial one) and the dhcp engine behind the GUI probably already support it but your right, it should be in the ideas section.
Thanks for considering it.
Done some testing about this. I downloaded the config, change both dhcpLanLimit and dhcpLANStart at 2 and uploaded the config:
"dhcpLanLimit": "2",
"dhcpLanStart": "2",
The antenna react juste fine. I tested the dhcp server with a EdgeRouter PoE, eth0 and eth1 both in dhcp client mode.
If I plug it to et0
$ show interfaces ethernet
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address S/L Description
--------- ---------- --- -----------
eth0 172.31.1.2/24 u/u
eth1 - u/D
eth2 - u/D
eth3 - u/D
eth4 - u/D
If I plug eth1
$ show interfaces ethernet
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address S/L Description
--------- ---------- --- -----------
eth0 - u/D
eth1 - u/u
eth2 - u/D
eth3 - u/D
eth4 - u/D
If I plug again in dhcp0
$ show interfaces ethernet
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface IP Address S/L Description
--------- ---------- --- -----------
eth0 172.31.1.2/24 u/u
eth1 - u/D
eth2 - u/D
eth3 - u/D
eth4 - u/D
Connected to antenna via static IP in same subnet and I don't see any error with the antenna. I was expecting a dhcp pool limit warning in log but nothing except a "snmpd DFS status" entrie. The only thing I see after uploading this config is a error shown in network so I can't save anychange without changing range.
So, it seem to be only a limit in the GUI that don't accept the variable dhcpLanStart = dhcpLanLimit while it's a perfectly legal operation for a dhcp server.
What I propose is to accept
dhcpLanLimit>=dhcpLanStart
and refuse
dhcpLanLimit<dhcpLanStart
Instead of
dhcpLanLimit>dhcpLanStart
and refuse
dhcpLanLimit=<dhcpLanStart
From CLI, since it seem we edit directly the value without check, nothing have to be done to fix it. I was able to set dhcpLanLimit at 4 and dhcpLanStart at 6 on a /30 subnet, apply and save without any problem. LOL
>config show json
...
"dhcpLanLimit": "2",
"dhcpLanStart": "2",
...
>config save
>config show json
...
"dhcpLanLimit": "4",
"dhcpLanStart": "6",
...
Would show the command history but the seem to be a problem with this command. I will report it on the forum.
Still not fix in 2.6.2.1
If I configure a /30 network with dhcp, pool, starting address will be ithe same as nterface adress, and GUI don't return any error, but same address for pool starting and ending address is not accepted so starting address must be the same as interface address for a /30
Modify it via CLI don't seem to work anymore :-/ but download / upload still work.
Hi Mike,
In 2.6.2.1 Release DHCP settings follow common DHCP logic.
In /30 subnet only 2 IP addresses are available for distribution. DHCP section shows one of them as Starting and Second as Ending.
It is true that ePMP interface has assigned one of IP addresses from DHCP pool of /30 subnet, because of interface should be in the same subnet.
But other device in /30 subnet will receive proper IP address different from interface's IP address.
I would be really apreciate it if you could describe your view how it should work with /30 subnet.
Thank you.