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New Member

NAT and multiple public IP addresses

Hi,

I am trying to configure the following on an 877 router:

  • One outside (public) interface that is PPPoE with 8 IP addresses
  • 3 VLANs serving 3 test companies
  • Clients on each VLAN to go out on a diiferent public IP address

The config I currently have has been working for probably more than a year now and works well, the only part that doesn't work for me is each VLAN going out on it's own IP address.

My first question is: is this possible, at least on this router?

If it is then can anyone offer an example config?

I have been looking at getting this going for a while and looked in to a route-map and a pool but I'm not sure if i am going down the right lines.

Thanks

  • WAN Routing and Switching
1 ACCEPTED SOLUTION

Accepted Solutions

Re: NAT and multiple public IP addresses

Try this.

ip access-list extended NAT-vlan1
permit ip 10.1.1.0 0.0.0.255 any

ip access-list extended NAT-vlan2
permit ip 10.1.2.0 0.0.0.255 any


ip access-list extended NAT-vlan3
permit ip 10.1.3.0 0.0.0.255 any

xxx.xxx.xxx.xxx is your public addresses available on your PPPoE circuit.


ip nat pool P1 xxx.xxx.xxx.xx1 netmask 255.255.255.255
ip nat pool P2 xxx.xxx.xxx.xx2 netmask 255.255.255.255
ip nat pool P3 xxx.xxx.xxx.xx3 netmask 255.255.255.255

ip nat inside source list NAT-vlan1 pool P1 overload
ip nat inside source list NAT-vlan2 pool P2 overload
ip nat inside source list NAT-vlan2 pool P3 overload

Let me know, if this helps.

thanks

4 REPLIES

Re: NAT and multiple public IP addresses

Try this.

ip access-list extended NAT-vlan1
permit ip 10.1.1.0 0.0.0.255 any

ip access-list extended NAT-vlan2
permit ip 10.1.2.0 0.0.0.255 any


ip access-list extended NAT-vlan3
permit ip 10.1.3.0 0.0.0.255 any

xxx.xxx.xxx.xxx is your public addresses available on your PPPoE circuit.


ip nat pool P1 xxx.xxx.xxx.xx1 netmask 255.255.255.255
ip nat pool P2 xxx.xxx.xxx.xx2 netmask 255.255.255.255
ip nat pool P3 xxx.xxx.xxx.xx3 netmask 255.255.255.255

ip nat inside source list NAT-vlan1 pool P1 overload
ip nat inside source list NAT-vlan2 pool P2 overload
ip nat inside source list NAT-vlan2 pool P3 overload

Let me know, if this helps.

thanks

New Member

NAT and multiple public IP addresses

Thank you very much for your response, i will try this in a while when i get the chance.  One further question though, do I need to assign all the IP addresses as secondary in my dialer interface?

Thanks

Iain

NAT and multiple public IP addresses

"One further question though, do I need to assign all the IP addresses as secondary in my dialer interface?"

No, but those public IPs in question, must be available on PPPoE circuit, assinged to you by your ISP.

thanks

New Member

Re: NAT and multiple public IP addresses

Hi rizwanr,

Many thanks for your help, i basically already had it but was just being a donkey, I just needed to change the local pool i was trying to use into a NAT pool

Thanks

Iain

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