Prevent pfSense from sending DHCP options 12 and 61 in "Discover" message on WAN

NorthernDiesel

Hello All,
My first post - thanks to all for the intense reading that has got me to (almost) getting my network correctly setup on my first pfSense install.

My problem is as follows: My ISP provides Internet and IPTV on two VLANS (35/34) using DHCP. 35 is ok, getting an IP no problem. 34 is getting no response (Wireshark sees only my end's Discover message, no response)

I have captured the complete DHCP conversation my ISP-provided router has with my ISP, and it responds immediately when I plug it in. I have forced pfSense (at great pain) to replicate DHCP options 125 "Vendor Specific Information" (with suboptions) and 60 "Vendor class identifier" such that the DHCP Discover is identical to that sent by the original router, with only two exceptions:

I can't prevent pfSense from sending option 61 and 12 messages "Client Identifier" and "Host name". My ISP's router does not send these.
The order of the options is different.

That is bitwise the only difference between the messages as seen by Wireshark.
I have tried composing my own dhclient.config file and overriding the interface, and pfSense is correctly using that file, but still adds option 61 and 12 messages ontop of my config.

How can I stop pfSense from doing this?!?!

teunbruijnen

@northerndiesel Hello!! It has been a while since your post. I am currently in a similar position and was wondering if you were able to succeed? Kind regards

sebz29a

@teunbruijnen hi i'm in the same situation i want to prevent sending option 12 Host name in a DHCP discover did you find a solution ? Thanks

NorthernDiesel

Hey @sebz29a and @teunbruijnen, I eventually traced the issue to a different cause and never solved it directly, unfortunately.
I eventually moved the WAN NIC into PCIe passthrough and the DHCP issue disappeared.

schnee

Old post, but anyways I post my discoveries here.

To surrpress an option the easiest way is to add it to the send options under advanced. For

option 12 add host-name "",
option 61 add dhcp-client-identifier ""