Cisco 2900 DHCP and dual boot machines

[roncro]

Hello,

I have a machine that runs RHEL/Centos 7.x, but sometimes is booted with Ubuntu, and on rare occasions windows.

Apparently the router's dhcp service sees  RHEL/Centos being booted with the hardware address XX:XX:XX:XX:XX:XX and sees windows booting with 01XX:XXXX:XXXX:XX (and depending on the Ubuntu version, it can be either)

Is there a way around it in DHCP?  (I tried using both records, but then the last one mentioned is the one used by dhcp.

thanks,

Ron

[paul driver]

Hello

Any reason why these mac addresses cannot have a different up address?

[roncro]

I don't really understand what you mean by that.

would be convenient if it would at least understand the HW address, or could use multiples.

(I don't really understand the state/up address concept to be real honest).

Ron

[paul driver]

Hello

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@roncro wrote:
Apparently the router's dhcp service sees RHEL/Centos being booted with the hardware address XX:XX:XX:XX:XX:XX and sees windows booting with 01XX:XXXX:XXXX:XX (and depending on the Ubuntu version, it can be either)

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The dhcp server sees differing mac-addresses for this one machine so you can statically reserve a different ip address for this one machine in the servers dhcp scope, that’s if this is applicable for you or you can assigned the one ip address associated from the switchport that machine is connected to, so no matter what mac-address originates from that port the dhcp server will allocate the same ip, is this what you wish?

[roncro]

well yeah,  I figured I could do that, but it's annoying.

I was just wondering if it could be avoided

[paul driver]

Hello

Yes it can if that what you want-  please confirm?

[roncro]

well, I am looking to see if there is a way to have dhcp use the hardware address always, regardless of what 'state' and adapter is in, or what is running on it. Possibly just set up a separate dhcp server if that's easier or more flexible.

thanks,

Ron

[paul driver]

hello

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@roncro wrote:

well, I am looking to see if there is a way to have dhcp use the hardware address always, regardless of what 'state' and adapter is in, or what is running on it. Possibly just set up a separate dhcp server if that's easier or more flexible.

thanks,

Ron

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use the dhcp port based allocation as per your link 

[roncro]

i saw that there is something called  "server port based address allocation"

like here:

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/15-sy/dhcp-15-sy-book/dhcp_server_port-based_address_allocation.html#GUID-B3235DCE-2C69-41E2-B505-9821B052209A

Does that mean that when the router  receive a discover packet,  and I tell it to use the HW address, it will use the hardware address regardless of what the client tries to tell the router, dhcp server?

Ron

[paul driver]

Hello
it means as i have stated , you can allocate a reserved ip address to a specific port , so no matter what device is connected to it the same ip address will be allocated.