Address and port translation between internal networks

[Sinisa Hreljac]

Hi to all,

I have a situation like on attached picture. Central router 891 is currently Mikrotik router and it should be migrated to Cisco router.

Internal networks are defined by VLANs, and outside interface to ISP is physical Gi0. I have configured on outside interface "ip nat outside" and on VLANs "ip nat inside". Also, global config "ip nat inside source list 199 interface GigabitEthernet0 overload" is applied and all internal VLANs can access internet, so this is OK.

However, there is one more need, that traffic to one specific IP and port on internet (for this purpose let say it is IP 9.9.9.9 tcp/999) from VLAN10 or host 10.10.0.10  should be redirected to HOST B and some other port.

When service on HOST A which have IP address 10.10.0.10 initiate tcp connection to 9.9.9.9 port 999, that connection should be redirected to 192.168.0.10 port 777. On Host B, source of this connection should not be changed (it should be 10.10.0.10).

On Mikrotik this is possible and very easy to configure. Is this possible on Cisco 891 router and how?

Thanks.  

[paul driver · Accepted solution]

Hello
If you will require an internal host so it can be accessed internally from its inside global address (translated ip/port address -PAT)
then you have two options to accomplish this.

• Change you nat to NVI nat (domainless nat – no inside/outside domains (most simplistic)
• Hairpinning.

Please see attached txt file.