mipsbe 5.0 to 5.12 strange DHCP OFFER problem

RouterOS General
1

Hi there, i’ve got an absurd problem and i don’t understand the reason.

I’ve got an ethernet interface of a 493AH where i’ve configured a listening dhcpd service.

Now with many dhcp clients i don’t have any problems, but with the dhcp client of "Virtual Access GW2040 3G Router " (http://www.virtualaccess.ie/gw2040.html) something go wrong.

Client like usual start a dhcp process with a DHCP DISCOVER packet
discover.cap.zip (225 Bytes)
with all the values correctly set, but when dhcpd daemon on the mikrotik board reply with the DHCP OFFER packet
offer.cap.zip (225 Bytes)
there’s no “DHCP option 1” (subnet mask) in the packet so that client silently refuse the offer and DHCP process go wrong.

Any idea??

I attached also here dhcp,debug output:

Feb/08/2012 15:42:51 dhcp,debug,packet dhcp1 received discover with id 3214 from 0.0.0.0
Feb/08/2012 15:42:51 dhcp,debug,packet ciaddr = 0.0.0.0
Feb/08/2012 15:42:51 dhcp,debug,packet chaddr = 00:E0:C8:81:0A:78
Feb/08/2012 15:42:51 dhcp,debug,packet Msg-Type = discover
Feb/08/2012 15:42:51 dhcp,debug,packet Client-Id = 01-00-E0-C8-81-0A-78
Feb/08/2012 15:42:51 dhcp,debug,packet Host-Name = 76-61-2D-65-31-00
Feb/08/2012 15:42:52 dhcp,debug,packet dhcp1 sending offer with id 3214 to 172.16.1.100
Feb/08/2012 15:42:52 dhcp,debug,packet ciaddr = 0.0.0.0
Feb/08/2012 15:42:52 dhcp,debug,packet yiaddr = 172.16.1.100
Feb/08/2012 15:42:52 dhcp,debug,packet siaddr = 172.16.1.254
Feb/08/2012 15:42:52 dhcp,debug,packet chaddr = 00:E0:C8:81:0A:78
Feb/08/2012 15:42:52 dhcp,debug,packet Msg-Type = offer
Feb/08/2012 15:42:52 dhcp,debug,packet Server-Id = 172.16.1.254
Feb/08/2012 15:42:52 dhcp,debug,packet Address-Time = 3600

Regards,

2

ping

3

I also have a problem with a Inova OnTime IP Clock.

I have the same model, same problem. I configured a linux DHCP Server and works right away.

Version 5.13

Can we have an answer from Mikrotik please?

Thanks.

4

I have the same problem.

Though, I found out that my client (not yours either) does not send a Parameter Request List (Option 55) in the discover packet.
Therefore, the MicroTik dhcp server does not add the Subnet Mask (Option 1) in the offer.

Other dhcp servers sends this Subnet Mask in any way, (which sounds pretty decent).

Is there a way to “force” RoterOS dhcp server to reply with Subnet Mask even though it was not requested?

5

Cool discover!!!

Mk staff any suggestions?

6

Hello,

Have the same issue. Any ideas?