Grandstream GXV3450 does not get DHCP lease from Mikrotik

RouterOS General
1

Hello,
You can see in the attachment that the phone does not like dhcp option 42 for time. It was set for “0.pool.ntp.org” and this caused the DORA process to fail at “O”.
Based on the DHCP packet response to Discover included in the pcap trace, it appears the Mikrotik sends an incorrect length 14 instead of 12 for option 42. The standard RFC2132 requires that Time Server length should be multiples of 4. Refer the RFC2132 DHCP Options and BOOTP Vendor Extensions document below for further information. Look at the point 3.6 Time Server Option
https://datatracker.ietf.org/doc/html/rfc2132
ROS v7.10

Am I missing something?

Thank you.
Screenshot 2023-07-13 192047.png

2

The rfc states that option 42 needs to be a list of ip addresses. (not dns records)

https://www.rfc-editor.org/rfc/rfc2132

If you want to use a dns record you will most likely need to schedule a script that resolves the dns record and updates the dhcp options.

3

Hmm.. OK, I’ll give that a try. Thanks!