nat on loopback

[n.bokhar1]

hi i have this topology

linux: 10.2.2.100

win  : 10.2.2.50

i also have two loopback interfaces

loop1 : 1.1.1.1 255.255.255.255

loop2 : 2.2.2.2 255.255.255.255

both interfaces have ip nat outside under config

and i have these nats as well

ip nat inside source static 10.2.2.50 interface loop 1

ip nat inside source static 10.2.2.100 interface loop 2

now i want to connect to my window machine from Linux on 1.1.1.1 ip address 

but i cant

how can i do that ?

[Julio E. Moisa]

Hi

The switches cannot run NAT, it should be configured on the router, so your configuration should be:

ROUTER

interface loopback 1

ip address 1.1.1.1 255.255.255.255

interface loopback 2

ip address 2.2.2.2 255.255.255.255

interface g0/0

description >>INTERNAL NETWORK<<

ip nat inside

interface g0/1

description >>INTERNET or EXTERNAL NETWORK<<

ip nat outside

ip nat inside source static 10.2.2.50 <interface loop 1 IP address>

ip nat inside source static 10.2.2.100 <interface loop 2 IP address>

ip route 0.0.0.0 0.0.0.0 <public or next hop IP> 

** Now if it is used to translate to Internet, the IP addresses used with the loopback should be public IP addresses provided by an ISP.

Hope it is useful

:-)

[n.bokhar1]

it is configured on the router

[n.bokhar1]

switch is just there for basic connectivity

[Julio E. Moisa]

Hi,

Thank you, thas is correct. 

[Muhammad Uzair]

As sir Julio confirmed config is okay, just give it a try with IP address instead than interface(s).

ip nat inside source static 10.2.2.50 1.1.1.1

ip nat inside source static 10.2.2.100 2.2.2.2

Thank you.

Kindest regards,

Uzzi

[Julio E. Moisa]

Thank you Muhammad, you are right, it was fixed  

:-)

[n.bokhar1]

thank you guys for your replies but that didn't work any other solutions?

[Julio E. Moisa]

Hi

Could you please share your configuration, switch and router

Thank you

[n.bokhar1]

SWitch:
interface GigabitEthernet0/0
switchport mode access
media-type rj45
negotiation auto
!
interface GigabitEthernet0/1
switchport access vlan 2
switchport mode access
media-type rj45
negotiation auto
interface Vlan1
ip address 10.1.1.1 255.255.255.0
shutdown
!
interface Vlan2
ip address 10.2.2.1 255.255.255.0
!
ip forward-protocol nd
!
ip route 0.0.0.0 0.0.0.0 10.1.1.2
Router :
interface Loopback1
ip address 1.1.1.1 255.255.255.255
ip nat outside
ip virtual-reassembly in
!
interface Loopback2
ip address 2.2.2.2 255.255.255.255
ip nat outside
ip virtual-reassembly in
!
interface GigabitEthernet0/0
ip address 10.1.1.2 255.255.255.0
ip nat inside
ip virtual-reassembly in
duplex auto
speed auto
media-type rj45
!
interface GigabitEthernet0/1
ip address 172.18.1.1 255.255.255.0
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
media-type rj45

ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
ip nat inside source list NAT interface GigabitEthernet0/1 overload
ip nat inside source static 10.2.2.50 interface Loopback2
ip nat inside source static 10.2.2.100 1.1.1.1
!
ip access-list standard NAT
permit any
!

[Julio E. Moisa]

Hi

The loopback address must be known through the next hop, for example:

SWITCH ----- ROUTER (cient) ---- ROUTER (ISP)

ROUTER (client)

* IP nat outside is not required under the loopback interfaces, it can be removed

* You need to add a default route: 0.0.0.0 0.0.0.0 <next hop IP - ISP router interface IP address>

 something like:

 ip route 0.0.0.0 0.0.0.0 172.18.1.2

The IPS's router must know the following IP addresses: 
1.1.1.1/32
2.2.2.2/32

so you could create:

ip route 1.1.1.1 255.255.255.255 <next-hop IP - Client's router Interface IP>

ip route 2.2.2.2 255.255.255.255 <next-hop IP - Client's router Interface IP>

Hope it is useful

:-)

[paul driver]

Hello

Not sure if you wanted the loopbacks of the rrtr to be natted to a static 172.18.1 x address however in the example below i have applied such nat.

You also have some mis-configuration on the switch regards the vlans and connection to the rtr.

see example below:

Switch:
conf t
ip routing
interface Vlan1
no shutdown

no ip route 0.0.0.0 0.0.0.0 10.1.1.2
ip route 0.0.0.0 0.0.0.0 vlan 1 10.1.1.2

Router :
conf t
ip route 10.2.2.0 255.255.255.0 gig0/0 10.1.1.1
ip route 0.0.0.0 0.0.0.0 gig0/1 172.18.1.x  < isp lan facing ip address)

interface Loopback1
ip nat inside

interface Loopback2
ip nat inside

interface GigabitEthernet0/0
ip nat inside

interface GigabitEthernet0/1
ip nat outside

no ip nat inside source static 10.2.2.50 interface Loopback2
no ip nat inside source static 10.2.2.100 1.1.1.1
no ip access-list standard NAT

ip access-list standard NAT
permit ip 10.1.1.0 0.0.0.255 any
permit ip 10.2.2.0 0.0.0.255 any

ip nat source static 1.1.1.1 172.18.1.x
ip nat source static 2.2.2.2 172.18.1.x
 

res
Paul

[n.bokhar1]

thanks to all you guys for your replies but they are not what i look for and also don't work

this is my network i have no other stuff

i want to connect to server 2 from server 1 but with 1.1.1.1 ip address which is set on my routers loopback it is fully working when i connect to the server from the internet but when i do it from server 1 it fails and when i telnet to 1.1.1.1 from server 1 the router cli opens up witch i don't want 

so what can i do to :

telnet from server 1 to 1.1.1.1 and my server 2 cli opens not the router.

[n.bokhar1]

i also tried a bunch of other ios versions and other routers they are all do the same

[paul driver]

Hello

thrn you will need to nat hairpin to achieve that

https://supportforums.cisco.com/t5/wan-routing-and-switching/nat-reflection-nat-hairpin-on-a-cisco-router/td-p/3302833

 https://supportforums.cisco.com/t5/wan-routing-and-switching/nat-hairpinning/td-p/2475807

Res

paul