How to use Public Ip address on switch

[shahbaz1981]

Hi,

I am using Cisco 3825 router and 3750 switch in my network.

My query about to use  public ip in  my lan client PC .

I have two isp directly connected to my router both Ip address  block is /30

i have /27 public ips pool from one ISP and i want to assign it to my switch clients .i do not want to use static NAT .

[Reza Sharifi]

Hi,

a /27 will give you 30 use-able IP addresses.  As long as you have 30 or fewer devices, you can assign public IPs to your end devices.  If you have more than 30 devices than you need NAT and use private IPs.

HTH

[shahbaz1981]

thanks for your reply ....

but my query is that i want to use these public ips on my switch connected PC . 

[Reza Sharifi]

Yes, you can.  assuming the switch is just layer-2, connect all PCs to the switch, configure a vlan and put all the devices in it. connect the switch to the router and configure the same vlan on the uplink port to the router.  On the router interface configure an IP address in the /27 range and give each device also an IP address in the /27 range. The default gateway for your PCs should be the IP address of the router. On the router, configure a default route to point to your provider IP address (/30).

HTH

[shahbaz1981]

Bundle of thanks  ...

how can i secure my switch network b/c its now have public ip address .

[Jon Marshall]

You either need a firewall or you can run the IOS firewall ZBFW on your router if you have the right feature set.

Alternatively you could rely purely on acls on the router but with public IPs on your inside devices that would not be recommended.

Jon

[shahbaz1981]

thanks

[shahbaz1981]

Configured and connectivity is ok but no browsing