DHCP not giving ip just to one client

RouterOS General
1

Hi All…

I have a Mikrotik RB 450G with a dhcp server, all clients get the ip via DHCP, works for almost all clients, just one machine that is no receiving the ip.

Why is that ? all clients are Dell Vostro 270s, all others get the dynamic ip, just one doens´t…

do you have any ideas what could be ?

here is the dhcp server log:

17:26:08 dhcp,debug,packet     ciaddr = 0.0.0.0 
17:26:08 dhcp,debug,packet     chaddr = 74:86:7A:F6:14:F9 
17:26:08 dhcp,debug,packet     Msg-Type = discover 
17:26:08 dhcp,debug,packet     Client-Id = 01-74-86-7A-F6-14-F9 
17:26:08 dhcp,debug,packet     Address-Request = 192.168.88.249 
17:26:08 dhcp,debug,packet     Host-Name = "CV-004" 
17:26:08 dhcp,debug,packet     Class-Id = "MSFT 5.0" 
17:26:08 dhcp,debug,packet     Parameter-List = Subnet-Mask,Domain-Name,Router,Dom
ain-Server,NETBIOS-Name-Server,Unknown(46),Unknown(47),Unknown(31),Static-Route,Cl
assless-Route,MS-Classless-Route,Vendor-Specific 
17:26:08 dhcp,debug,packet Dhcp-CV-Office received request with id 1199121924 from
 0.0.0.0 
17:26:08 dhcp,debug,packet     ciaddr = 0.0.0.0 
17:26:08 dhcp,debug,packet     chaddr = 74:86:7A:F6:14:F9 
17:26:08 dhcp,debug,packet     Msg-Type = request 
17:26:08 dhcp,debug,packet     Client-Id = 01-74-86-7A-F6-14-F9 
17:26:08 dhcp,debug,packet     Address-Request = 192.168.88.249 
17:26:08 dhcp,debug,packet     Server-Id = 192.168.88.1 
17:26:08 dhcp,debug,packet     Host-Name = "CV-004" 
17:26:08 dhcp,debug,packet     Unknown(81) = 00-00-00-43-56-2D-30-30-34 
17:26:08 dhcp,debug,packet     Class-Id = "MSFT 5.0" 
17:26:08 dhcp,debug,packet     Parameter-List = Subnet-Mask,Domain-Name,Router,Dom
ain-Server,NETBIOS-Name-Server,Unknown(46),Unknown(47),Unknown(31),Static-Route,Cl
assless-Route,MS-Classless-Route,Vendor-Specific 
17:26:08 dhcp,debug,packet Dhcp-CV-Office sending offer with id 1199121924 to 192.
168.30.237 
17:26:08 dhcp,debug,packet     ciaddr = 0.0.0.0 
17:26:08 dhcp,debug,packet     yiaddr = 192.168.30.237 
17:26:08 dhcp,debug,packet     siaddr = 192.168.30.1 
17:26:08 dhcp,debug,packet     chaddr = 74:86:7A:F6:14:F9 
17:26:08 dhcp,debug,packet     Msg-Type = offer 
17:26:08 dhcp,debug,packet     Server-Id = 192.168.30.1 
17:26:08 dhcp,debug,packet     Address-Time = 259200 
17:26:08 dhcp,debug,packet     Subnet-Mask = 255.255.255.0 
17:26:08 dhcp,debug,packet     Router = 192.168.30.1 
17:26:08 dhcp,debug,packet     Domain-Server = 192.168.30.1 
17:26:11 dhcp,debug,packet Dhcp-CV-Office received inform with id 2786828895 from 
192.168.88.249 
17:26:11 dhcp,debug,packet     ciaddr = 192.168.88.249 
17:26:11 dhcp,debug,packet     chaddr = 74:86:7A:F6:14:F9 
17:26:11 dhcp,debug,packet     Msg-Type = inform 
17:26:11 dhcp,debug,packet     Client-Id = 01-74-86-7A-F6-14-F9 
17:26:11 dhcp,debug,packet     Host-Name = "CV-004" 
17:26:11 dhcp,debug,packet     Class-Id = "MSFT 5.0" 
17:26:11 dhcp,debug,packet     Parameter-List = Subnet-Mask,Domain-Name,Router,Dom
ain-Server,NETBIOS-Name-Server,Unknown(46),Unknown(47),Unknown(31),Static-Route,Cl
assless-Route,MS-Classless-Route,Vendor-Specific,Unknown(252) 
17:26:11 dhcp,debug,packet Dhcp-CV-Office sending ack with id 2786828895 to 192.16
8.88.249 
17:26:11 dhcp,debug,packet     ciaddr = 192.168.88.249 
17:26:11 dhcp,debug,packet     siaddr = 192.168.30.1 
17:26:11 dhcp,debug,packet     chaddr = 74:86:7A:F6:14:F9 
17:26:11 dhcp,debug,packet     Msg-Type = ack 
17:26:11 dhcp,debug,packet     Server-Id = 192.168.30.1 
17:26:11 dhcp,debug,packet     Domain-Server = 192.168.30.1,192.168.30.3 
17:27:37 dhcp,debug,packet Dhcp-CV-Office received inform with id 3701793061 from 
192.168.88.249 
17:27:37 dhcp,debug,packet     ciaddr = 192.168.88.249 
17:27:37 dhcp,debug,packet     chaddr = 74:86:7A:F6:14:F9 
17:27:37 dhcp,debug,packet     Msg-Type = inform 
17:27:37 dhcp,debug,packet     Client-Id = 01-74-86-7A-F6-14-F9 
17:27:37 dhcp,debug,packet     Host-Name = "CV-004" 
17:27:37 dhcp,debug,packet     Class-Id = "MSFT 5.0" 
17:27:37 dhcp,debug,packet     Parameter-List = Subnet-Mask,Domain-Name,Router,Dom
ain-Server,NETBIOS-Name-Server,Unknown(46),Unknown(47),Unknown(31),Static-Route,Cl
assless-Route,MS-Classless-Route,Vendor-Specific,Unknown(252) 
17:27:37 dhcp,debug,packet Dhcp-CV-Office sending ack with id 3701793061 to 192.16
8.88.249 
17:27:37 dhcp,debug,packet     ciaddr = 192.168.88.249 
17:27:37 dhcp,debug,packet     siaddr = 192.168.30.1 
17:27:37 dhcp,debug,packet     chaddr = 74:86:7A:F6:14:F9 
17:27:37 dhcp,debug,packet     Msg-Type = ack 
17:27:37 dhcp,debug,packet     Server-Id = 192.168.30.1 
17:27:37 dhcp,debug,packet     Domain-Server = 192.168.30.1,192.168.30.3 
17:27:51 dhcp,debug,packet Dhcp-CV-Office received request with id 2395865088 from
 192.168.30.6 
17:27:51 dhcp,debug,packet     ciaddr = 192.168.30.6 
17:27:51 dhcp,debug,packet     chaddr = 10:60:4B:DF:A7:44 
17:27:51 dhcp,debug,packet     Msg-Type = request 
17:27:51 dhcp,debug,packet     Client-Id = 01-10-60-4B-DF-A7-44 
17:27:51 dhcp,debug,packet     Host-Name = "HPDFA744" 
17:27:51 dhcp,debug,packet     Parameter-List = Domain-Server,Router,Subnet-Mask,D
omain-Name,Unknown(66),Unknown(67),Unknown(13),NETBIOS-Name-Server,Host-Name,Unkno
wn(81) 
17:27:51 dhcp,debug,packet Dhcp-CV-Office sending ack with id 2395865088 to 192.16
8.30.6 
17:27:51 dhcp,debug,packet     ciaddr = 192.168.30.6 
17:27:51 dhcp,debug,packet     yiaddr = 192.168.30.6 
17:27:51 dhcp,debug,packet     siaddr = 192.168.30.1 
17:27:51 dhcp,debug,packet     chaddr = 10:60:4B:DF:A7:44 
17:27:51 dhcp,debug,packet     Msg-Type = ack 
17:27:51 dhcp,debug,packet     Server-Id = 192.168.30.1 
17:27:51 dhcp,debug,packet     Address-Time = 259200 
17:27:51 dhcp,debug,packet     Domain-Server = 192.168.30.1 
17:27:51 dhcp,debug,packet     Router = 192.168.30.1 
17:27:51 dhcp,debug,packet     Subnet-Mask = 255.255.255.0 
17:28:38 system,info,account user admin logged in from 192.168.30.254 via telnet 

[admin@CV-OFFICE] /log>
2

17:27:37 dhcp,debug,packet Dhcp-CV-Office received inform with id 3701793061 from
192.168.88.249
17:27:37 dhcp,debug,packet ciaddr = 192.168.88.249

Are you sure this device does not have a static ip assigned?

3

yes, no static ip… it´s set to get dynamic…

I realy don´t undestand what is going on…

now I just found that there 2 machines with this problem, the rest are fine.

4

What range of IPs do you have in IP Pool and how many DHCP clients do you have?

5

The range is for from 192.168.30.10 - 192.168.30.254 , and I have only 50 machines… so I guess the ip range is not the problem.

Is something on windows on the network adpter, even set to get dynamic IP, something is saying to get that other IP.

On the same box, I have a wireless card, when I use is to get the IP, it gets the correct one…

Is there a way to reset the config on windows relates the network adpter ?

6

The RB450 by default has 192.168.88.1/24 assigned to ether2 (ether2-ether5 on a switch) with a dhcp server. You disabled or removed those, correct?

If the device is set to get an ip by dhcp, it is getting 192.168.88.249 from somewhere. Have you checked the network for a rogue dhcp server?
http://wiki.mikrotik.com/wiki/Manual:IP/DHCP_Server#Alerts

Maybe this has something to do with it?
http://forum.mikrotik.com/t/rb450g-vlan-dhcp-help/65955/6
Do you still have 2 dhcp servers on the same physical interface?

7

That article was about another setup in another company.

On this today, it’s just one network with one dhcp.

So far, I can tell that the problem relies on the win 7, looks like it’s ignoring the chack on dhcp to get dynamic ip and it’s using the last staic ip address it had.

I’ve tried everything, so my last option is to format and install win 7 again… tried to find any command that cleans/reset anything related to network adapter with no sucess. Even unistalling and installing the adpter again wont override this config with the old static ip address.

By the way, the adpter never had static ip, this IP is the old one before I change the router, after the change, win7 keeps asking to receive the old address…

cheers

8

Try this on Windows machines:

Reset WINSOCK entries to installation defaults: netsh winsock reset catalog

Reset TCP/IP stack to installation defaults. netsh int ip reset reset.log

9

What version RouterOS are you using? I had a bit of trouble with a couple devices renewing leases, but that is supposed to be fixed in V6.2. If you are using V6.2, maybe you should contact Mikrotik support about it. They were not certain how the fix may affect other devices.

I also had a problem similar to that when one of my customers decided to put a router on my network so they could “share” the purchased connection with family/friends, but did not disable the dhcp server. The alert function found that.

10

yes.. I am using 6.2… what is the channel to the mikrotik Support ? here in the forum or there is another channel ?

There is no other device on my network… just setup de alert and there is no alerts of another dhcp server…

cheers

11

You must email support(at)mikrotik.com for support on this issue. I let the development team into my router for a few hours to troubleshoot my problem. They will probably want you to do a supout file and send it to them first. Do that supout asap after the dhcp fail.

/system sup-output
12

Just found the problem… My intern guy plugged another rb450g to setup it and forgot to unplug… it was responding for the leases for some machines…

That´s righ, there was another dhcp server on the network.

By the way, why some machines was getting from one rb and others from the other one?

intern guy… go figure…

cheers