Manual binding Mac to IP

[jeevan.koganti]

Hi,

I am trying to bind Mac address manually to IP in Cisco 881 router so that if user wants to change the IP address also they should get the same IP.

I have configured as below but it is not working.

ip dhcp pool Test

host 192.168.0.10 255.255.255.0

hardware-address xxxx.xxxx.xxxx.xxxx

this IP was excluded from dhcp range

ip dhcp excluded-address 192.168.0.10

Can anyone tell where i am doing wrong.

Thanks in advance.

Regards,

Jeevan.

[Bibin Paul]

Hi Jeevan,

As u have alreday excluded the ip address from DHCP pool this ip wont be relesed when the user trying to connect. The user can mannually configure this ip address.

[cadet alain]

Hi,

-don't exclude the ip address otherwise your dhcp server will never allocate it to clients

-remove the dynamic binding first with clear ip dhcp binding 192.168.0.10

- try client-identifier 01xx.xxxx.xxxx.xx instead of hardware-address in your host pool

Regards

Alain

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[jeevan.koganti]

Hi,

sorry i typed it wrong i have excluded 192.168.0.1 192.168.0.9

and 192.168.0.11 192.168.0.254

but still not working.

[cadet alain]

Hi,

have you done point 2 then create the host pool with the client-identifier command ?

have you got a parent network pool ?

Regards

Alain

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[jeevan.koganti]

Hi Cadet,

Thanks for the reply let me try that option.

Moreover can i am also trying peer to peer app using class-map but it is not working can you help me on this.

Regards,

Jeevan.

[cadet alain]

Hi,

let's solve the dhcp problem first, will you ?

post  output from sh run | s ip dhcp and sh ip dhcp binding

Regards

Alain

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[jeevan.koganti]

Hi,

Please check the config

ip dhcp excluded-address 192.168.111.1 192.168.111.119

ip dhcp excluded-address 192.168.111.160 192.168.111.254

!

ip dhcp pool Test

network 192.168.111.0 255.255.255.0

default-router 192.168.111.8

dns-server 192.168.111.1

update arp

!

ip dhcp pool jeevan

host 192.168.111.120 255.255.255.0

client-identifier 08ed.b94d.8cfe

But still no luck. please guide me where i am going wrong.

Regards,

Jeevan.

[cadet alain · Accepted solution]

Hi,

client-identifier 08ed.b94d.8cfe   this is not a valid client-identifier but a MAC address so the correct identifier is

0108.edb9.4d8c.fe and don't forget to clear the dynamic binding first if it exists:

-to see it type sh ip dhcp binding 192.168.111.120

-to clear it clear ip dhcp binding 192.168.111.120

Regards

Alain

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[jeevan.koganti]

Hi,

Thanks for the support now it is working.

But if the particular system if offline i recognised that IP can be used by another user ( Static IP ) which i dont required.

Can u help me on this.

Thanks,

Jeevan.

[jeevan.koganti]

Hi Alain,

I am awaiting for your reply on the above..

After binding IP to MAC for DHCP it is working, but if that particular user is offline then other user is able to use that IP.

Can u help me with that.

Thanks,

Jeevan.

[cadet alain · Accepted solution]

Hi Jeevan,

i'm also awaiting for your rating about the manual binding in dhcp which was your original post More seriously it is not a paid TAC here and people have also their work and life outside this forum so you should be a little bit more patient or if you want instantaneous answers get a TAC call.

anyway, concerning your second problem it could  be solved by using DHCP snooping and IP Source guard if you have a switch supporting this feature between your clients and your router.

other solutions :

-you could configure a static arp entry for this address on the router and at least the guy taking this address wouldn't be able to communicate with the intenet and other subnets

-if you know the port where the dhcp client is connected and it is always the same then you could do an port acl on other ports debying this source ip address.

-another  better solution is to prohibit users from changing their address with a  windows local or AD GPO.

Regards

Alain

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[vipinkanojia]

Hi,

I m sitting Cisco 9300 multilayer switch I m doing Manual binding with client identifier command and it is working fine but when I m trying to using hardware-address command then binding not working..can anybody help me what is the reason behind why hardware-aadress command not working.

Regards

Vipin