Catalyst 6509-E Disable Supernet DHCP IPs

[braden.bonner]

Hello!

We have started moving all of our DHCP servers onto a 6509-E Catalyst, but do not wish for X.X.X.0 and X.X.X.255 addresses to be handed out due to the lack of communicability that clients have with it. I acknowledge that it is a great tool for WANs, but in our LAN majority of our clients treat it as a /24 and therefore fail to access the required resources.

Thanks,

          Braden

[Jean-Pierre de Villeres]

Hi Braden,

Please use ip dhcp excluded-address x.x.x.0 / x.x.x.255 command.

For example:

Don't assign ip address 172.16.1.3 and 172.16.1.4 on DHCP server for client subnet 172.16.1.0/24

DHCP server#

ip dhcp pool CLIENT_NETWORK

 network 172.16.1.0 /24

 ip dhcp excluded-address 172.16.1.3
 ip dhcp excluded-address 172.16.1.4

[braden.bonner]

I have been using that, but was hoping there was a much more efficient way for our larger ranges.
Or, do you mean I can do x.x.x.0 and x.x.x.255
Thanks,

           Braden

[balaji.bandi]

If you looking more IP's to be in the same subnet - network 172.16.X.0 /XX (increase this /23  or depends on your requirement).

BB

[braden.bonner]

No, we are looking to make it so a DHCP pool between 192.168.1.X - 192.168.127.X does not hand out any .0 or .255 addresses.

Thanks,

          Braden