Refuse RFC1918 offers on DHCP WAN
On 2.3.x, if I want to reject DHCP offers from 192.168.100.0/24 how should that be entered?
When I try to enter it like this, it gets rejected for syntax:
I split this off since the other post was 3 years old and this is a different question.
You don't need to reject the entire subnet, just the DHCP server in that subnet, which is probably your modem at 192.168.100.1
Thanks Jim. Ok, I know in a past version (maybe 2.2 or 2.1) it did accept a subnet there. If it only accepts individual IPs now, the wording beneath the field should remove the "…place the IP address or subnet of the DHCP server…" since that is a bit confusing.
So you can not use subnet? What if your isp has a bunch of dhcp servers on the same subnet you want to block and only accept IP from different set of dhcp servers?
I agree with luckman212 if you can not use subnet in some form of /cidr or whatever then the "or subnet" should prob be removed from the description ;)
The text probably needs to be corrected. It may have allowed the entry before but I don't think it worked. According to the man page it only takes an IP address.
The reject statement causes the DHCP client to reject offers from
servers who use the specified address as a server identifier.
This can be used to avoid being configured by rogue or misconfig-
ured DHCP servers, although it should be a last resort - better
to track down the bad DHCP server and fix it.
I pushed a change to fix the description so that it only lists IP address, not subnet.
Thanks! I was about to submit my own PR but as I was about to push it, I noticed that you had already changed the text ;)