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DHCP custom options not taking values

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DHCP custom options not taking values

When trying to put option code 1 , it shows below error

IMG_20191018_144631.jpg

In my case , I need to use two 3 option codes in DHCP custom option but it shows above error. Is this the limitations of meraki

7 REPLIES 7
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Kind of a big deal

Re: DHCP custom options not taking values

DHCP Option 1 is used to send the subnet mask. So you can't specify that yourself.

 

Can you elaborate on which options you want to specify and why?

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Re: DHCP custom options not taking values

Screenshot_2019-10-19-08-20-24-28.png

 

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Re: DHCP custom options not taking values

Need to add options in meraki but like option 3 should have two entries but meraki not accepting two entries for same option. Also need to enter option 1 but after saving meraki is saying doesn't support.
Kind of a big deal

Re: DHCP custom options not taking values

To add multiple gateways, use option 3 once but with a list of IP addresses:

image.png

 

Like I said, option 2 is subnet mask and is automatically set to the mask of the VLAN for which you're configuring the DHCP options. That's why Meraki doesn't allow you to customize that.

 

Edit: Also, that second Option 3 shown in your screenshot is actually suboption 3 of Option 43 (all of the MSUCClient ones actually). For Skype 4 Business you need to configure those. More info here:

http://blog.schertz.name/2012/05/understanding-dhcp-option-43/

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Re: DHCP custom options not taking values

@BrechtSchamp So I have to use 43 in code in place of 3 in meraki custom option and it will solve my problem..right

Kind of a big deal

Re: DHCP custom options not taking values

Well the way I see it you need to put in option 43 with all of its sub options in the payload (Meraki doesn't have the front-end to specify sub-options so you'll have to manually construct the whole payload).

 

I haven't done this myself. But out of interest I'm willing to help you construct your option 43 payload. I would need the actual values of all your suboptions to do that though. And seeing as I have no way to really test it, you'd have to be my guinnea pig.

Getting noticed

Re: DHCP custom options not taking values

Options in DHCP are defined in RFC 2132, 3046 and 3495.  From the screenshot you took of your Microsoft DHCP, it appears the configuration you are trying to copy is non-standard.  You need to adhere to the RFC's and not assign your DHCP options according to your preference.  Vendor specific options start at 43.

 

iana.org has a good guide as to the expected option configuration per normal standards.

https://www.iana.org/assignments/bootp-dhcp-parameters/bootp-dhcp-parameters.xhtml

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