Nat on a network with 3 routers

[orics94]

Hey, I'm kind of new in ccna and I'm clueless on how to nat this topology, I've been trying now for over 2 days, I'll take all the help I can get, thanks

The network for router0 and the pc's is 192.168.0.0/24

[Flavio Miranda]

Hi start by define the traffic

ip access  list 1 permit 192.168.0.0

Then, enable nat on interfaces

Int gx 

 ip nat inside

inty

ip nat outside

Then you configure

ip nat inside source list 1 overload

Int gx - local network 192.168.0.0

Inty - 172.31.0.x

On the next router you can repeat the process but now you traffic is different

ip access list 1 permit 172.31.0.x (router 0 interfaces)

You can share you file here. Just zip it first 

[orics94]

I should try the following on routers 0+1 right?

since I want to reach the web server with my pc's, I don't know what but something is missing for me

I attached the file aswell

thanks alot

[Flavio Miranda · Accepted solution]

Hi

 Find attached a working file.  You can see double NAT by using the command "show ip nat translation" on Router0 and Router 1.

Router0#sh ip nat tran
Router0#sh ip nat translations
Pro Inside global Inside local Outside local Outside global
icmp 172.31.0.2:109 192.168.10.3:109 172.19.0.200:109 172.19.0.200:109
icmp 172.31.0.2:110 192.168.10.3:110 172.19.0.200:110 172.19.0.200:110
icmp 172.31.0.2:111 192.168.10.3:111 172.19.0.200:111 172.19.0.200:111
icmp 172.31.0.2:112 192.168.10.3:112 172.19.0.200:112 172.19.0.200:112

Router1#sh ip nat translations
Pro Inside global Inside local Outside local Outside global
icmp 209.165.200.2:113 172.31.0.2:113 172.19.0.200:113 172.19.0.200:113
icmp 209.165.200.2:114 172.31.0.2:114 172.19.0.200:114 172.19.0.200:114
icmp 209.165.200.2:115 172.31.0.2:115 172.19.0.200:115 172.19.0.200:115
icmp 209.165.200.2:116 172.31.0.2:116 172.19.0.200:116 172.19.0.200:116

What was really bad on the router0 was this Access List:

access-list 100 deny ip 192.168.10.0 0.0.0.255 192.168.20.0 0.0.0.255

I also made some changes on routing but slightly changes.

You server does not have gaterway. They must have.

[orics94]

was the access list on r0 that bad? I used it to block traffic from vlan10 to vlan20

and what should I try to do for the pc's to be able to.reach the web server?

[Flavio Miranda]

Yes, that access list. That acl was also blocking the communication to the servers as well. 

 You cant put an access list with one statement and deny. The second statement is also deny implicit,  so,  everything will be blocked. 

 You need a permit any any bellow the deny

 The file I attached, PCs is communicating with servers just fine and doing NAT at router 0 and router 1

[Georg Pauwen]

Hello,

what instructions are you following ? They usually want you to NAT from a source to a destination (network)...so in your case, what is the source, and what is the destination ?

[orics94]

I need to nat the 172.31.0.0 network with the LAN2 network and should get access to the web server from the PC's

[Jitendra Kumar]

have to try to enable ip nat inside on the router R1 g0/0/1? if not check please if your routing is ok this should work.

Thanks,

Jitendra