Opened 6 years ago

Last modified 4 years ago

#3337 new defect

perfdhcp wrong merge MAC to packet template

Reported by: marcin Owned by:
Priority: medium Milestone: Outstanding Tasks
Component: perfdhcp Version:
Keywords: Cc:
CVSS Scoring: Parent Tickets:
Sensitive: no Defect Severity: Medium
Sub-Project: DHCP Feature Depending on Ticket:
Estimated Difficulty: 0 Add Hours to Ticket: 0
Total Hours: 0 Internal?: no


This is a bug report regarding use of template packets in perfdhcp, submitted by Torsten Goehler:

Dear Sirs,
I'm trying to factor template files for perfdhcp for DHCP performance testing.
I factored a template file containing the required options.
I used:
perfdhcp -R 1000 -T discover.hex <serverIP>
to start testing with 1000 simulated different MAC adresses.

according to the bootp standart the Client MAC is directly positioned after the relay IP. The expection was perfdhcp to count up the client MAC, which starts w "00:0c:01:02:03:04" if I dont't give the "-b mac=xx:xx:xx:xx" starting value.

This obviously works only if I dont't use a hex template file.
In case I use the perfdhcp in conjunction w a template file as mentioned, the altering client MAC address is inserted into the packet w an off set of 2 bytes after the relay IP which is weird. Even if I try to use "-b mac=xx:xx:xx:xx" and template file together the given mac gets inserted w that 2 bytes offset which makes it impossible to control the client mac togehther with defining other options which are nessesary to simulate proper address scope selection.

any ideas?
point to patch the source and re-compile?

Many thanks


Change History (2)

comment:1 Changed 6 years ago by tgoehler

Hi Marcin,
thx for your help.
I checked my traces according to your explanation and obviuosly the default value for -O seems to be 35 because thats the byte being counted up if I don't provide the -O switch.
But further he actual point is, that the MAC in a IPv4 DISCOVER starts an 28 not 29.
If I use -O 33 it works as expected.
funny is that If you use the tool w/o an template is places the random generated MAC at the right per default t the correct offset.
Annyway using -O 33 it works also w templates.

comment:2 Changed 4 years ago by tomek

  • Milestone changed from DHCP Outstanding Tasks to Outstanding Tasks

Milestone renamed

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