| Subject: | ISC 4.3.3-P1 - Server-side Option 57 dhcp-max-message-size not working |
| Date: | Wed, 22 Feb 2017 20:11:17 +0000 |
| To: | dhcp-bugs@isc.org |
| From: | "Christoph Aichhorn" <christoph.aichhorn@grz.at> |
Bug Report from www.isc.org:
Name: Christoph Aichhorn
Email: christoph.aichhorn@grz.at
Software Version: ISC 4.3.3-P1
OS: Infoblox
Subject:Server-side Option 57 dhcp-max-message-size not working
Bug Detail
===========
At the end of the Release notes following is documentated:
"If the dhcp-max-message-size option is specified in scope, and the
client didn't send this option, use the one specified in scope to
determine the maximum size of the response."
We need to use this server-side-option, because it's not possible to set this as client option in Windows 7.
As we are moving from Microsoft DHCP to ISC, and MS ignores the RFC defined max size of 574 Bytes, there was no problem with Microsoft DHCP when a client requested as many options within a DHCP INFORM packet that answer exceeded the max size of 574 bytes.
ISC is working correct as long as option 57 is not defined and returns only that amount of requested options that fits within 574 bytes.
After defining option 57 on the server side with a value of 1024 byte, the ISC DHCP continues to reply with maximum 574 byte long packets.
---
This email was received through isc.org Bug Submission Form