DHCP binding

[iosolutions1]

Hi,

I did this config :

ip dhcp pool Reserved_1

   host 192.168.10.170 255.255.255.0

   client-identifier 001f.3c4f.2d21

   default-router 192.168.10.1

But still after release&renew the IP on this PC it didnt get 192.168.10.170

I've tried to clear arp and dhcp binding and also reloaded the router. it doesnt bind my MAC.

Thanx,

      Arik

[skarthic]

i)Does the entry show up as "manual" in "Show ip dhcp mapping" output

ii)How are you connected to the DHCP server.Is there a L3 device between them?

iii) Are you getting any IP at all ? Are you getting the same IP that the PC had earlier before configuring the static map?

[cadet alain · Accepted solution]

client-identifier 001f.3c4f.2d21

this is not a valid client-identifier but it is the mac address of interface so 2 choices here: whether keeping this address but then chqnge the command client-identifier by hardware-address or leave the command but prepend 01 to the mac address which will give

client-identifier 0100.1f3c.4f2d.21

Regards.

Alain.

[skarthic]

You got that right..01 should be prepended for ethernet media as explained in the doc.

http://www.cisco.com/en/US/docs/ios/12_2/ip/configuration/guide/1cfdhcp.html#wp1001108

[iosolutions1]

Thanx. I'll check it again with the hardware-address option.

Arik

[iosolutions1]

OK I switch it to hardware-address but again when I release renew my IP - nothing..  

Thnx,

     Arik

[cadet alain]

Hi,

Then use client-identifier but prepending your mac with 01

Regards.

Alain.

[skarthic]

Hi,

Did you try checking what is the client identifier info receievd in the DHCP discover packet.

You can check this using "debug ip dhcp server packet" command. If you could post this output we can find what is the client identifier info

sent by the PC.

Regards.

[iosolutions1]

Alain, Karthic,
Thanx for your help, I changed it to the client-identifier 0100.1f3c.4f2d.21 and its working now.
maybe I can ask you one more thing:
I want to block one PC on my network. I tried doing so with mac binding and blocking the IP, but I notice that there is no problem to put other IP manualy and pass this block.
How can I block mac address ?
I know it can be done on switches but this commands dont apply on routers.

Thnx again,
Arik

[cadet alain]

Hi

You can do this with MQC:

class-map BAD_MAC

match source-address xxxx.xxxx.xxxx

policy-map BLOCK_BAD_MAC

class  BAD_MAC

drop

interface f0/0

service-policy input BLOCK_BAD_MAC

Regards.

Alain.

[iosolutions1]

Alain, Thanx,

Great, its working fine.