topic Re: NAT overload on asa 5520 in Network Security

NAT overload on asa 5520

shanemcanuff — Mon, 11 Mar 2019 16:12:57 GMT

I have a ASA 5520 and would like to know how to setup NAT overload so my internal users can access the internet with the one public IP I have.

Re: NAT overload on asa 5520

Collin Clark — Sun, 06 Sep 2009 23:47:41 GMT

global (outside) 1 interface

nat (inside) 1 10.0.0.0 255.0.0.0 0 0

Here's a link with some good NAT info.

http://tools.cisco.com/search/display?url=http%3A%2F%2Fwww.cisco.com%2Fen%2FUS%2Fproducts%2Fps6120%2Fproducts_configuration_example09186a008046f31a.shtml&pos=1&strqueryid=1&websessionid=tQ3rXdNFF5kNHv7DwDtFxox

Hope that helps

Re: NAT overload on asa 5520

shanemcanuff — Mon, 07 Sep 2009 00:34:28 GMT

I try that commands and I was unable to overload, do I need to setup any ACL?

Re: NAT overload on asa 5520

shanemcanuff — Mon, 07 Sep 2009 00:40:32 GMT

Which IP address should I put at the nat(inside)?

Re: NAT overload on asa 5520

kwillacey — Mon, 07 Sep 2009 01:07:23 GMT

You can either nat anything or ur specific subnet

nat (inside) 0.0.0.0 OR

nat (inside) 192.168.1.0

As long as you have ur nat global ur nat inside

and ur default route it should work

Re: NAT overload on asa 5520

rlisiecki — Mon, 07 Sep 2009 12:41:26 GMT

simple nat exaple attached

Re: NAT overload on asa 5520

shanemcanuff — Mon, 07 Sep 2009 14:42:57 GMT

guess I am missing something cause it did not work for me at all. Can someone look over my config.. plz.. I am using windows 7 and have problems getting to the GUI.

==================

: Saved

ASA Version 7.0(8)

hostname tempasa

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

names

dns-guard

interface GigabitEthernet0/0

nameif outside

security-level 0

ip address 69.160.74.206 255.255.255.252

interface GigabitEthernet0/1

nameif dmz

security-level 50

ip address 69.160.221.1 255.255.255.0

interface GigabitEthernet0/2

nameif inside

security-level 100

ip address 192.168.1.32 255.255.254.0

interface GigabitEthernet0/3

shutdown

no nameif

no security-level

no ip address

interface Management0/0

nameif management

security-level 100

ip address 192.168.1.1 255.255.255.0

management-only

ftp mode passive

pager lines 24

logging asdm informational

mtu outside 1500

mtu dmz 1500

mtu inside 1500

mtu management 1500

no failover

no asdm history enable

arp timeout 14400

global (outside) 1 interface

nat (inside) 1 0.0.0.0 0.0.0.0 0 0 route outside 0.0.0.0 0.0.0.0 69.167.64.205 1

timeout xlate 3:00:00

timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02

timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00

timeout mgcp-pat 0:05:00 sip 0:30:00 sip_media 0:02:00

timeout uauth 0:05:00 absolute

aaa authentication ssh console LOCAL

http server enable

<--- More --->

http 192.168.1.0 255.255.255.0 management

no snmp-server location

no snmp-server contact

snmp-server enable traps snmp authentication linkup linkdown coldstart

crypto ipsec security-association lifetime seconds 28800

crypto ipsec security-association lifetime kilobytes 4608000

telnet 192.168.0.0 255.255.254.0 inside

telnet timeout 5

ssh timeout 5

console timeout 0

dhcpd address 192.168.1.2-192.168.1.254 management

dhcpd lease 3600

dhcpd ping_timeout 50

dhcpd enable management

class-map inspection_default

match default-inspection-traffic

policy-map global_policy

class inspection_default

inspect dns maximum-length 512

inspect ftp

inspect h323 h225

inspect h323 ras

inspect rsh

inspect rtsp

inspect esmtp

inspect sqlnet

inspect skinny

inspect sunrpc

inspect xdmcp

inspect sip

inspect netbios

inspect tftp

service-policy global_policy global

Cryptochecksum:1d6053dae2b794b9159dab62f7af0f07

: end

tempasa#

Re: NAT overload on asa 5520

rlisiecki — Mon, 07 Sep 2009 14:58:24 GMT

nat (inside) 1 0.0.0.0 0.0.0.0 0 0 route outside 0.0.0.0 0.0.0.0 69.167.64.205 1 (I think this should be two lines)

nat (outside) 1 0.0.0.0 0.0.0.0

route outside 0.0.0.0 0.0.0.0 69.167.64.205 1

Re: NAT overload on asa 5520

shanemcanuff — Mon, 07 Sep 2009 15:59:05 GMT

should I be able to ping the outside interface from the inside interface?

Re: NAT overload on asa 5520

Kureli Sankar — Mon, 07 Sep 2009 16:10:44 GMT

You mean ping the outside interface from an inside host/pc?

No. You can only ping the closest interface to the PC. If the PC is on the inside you can only ping the inside interface IP.

If the PC is outside you can only ping the outside interface IP on the FW.

That is by design.

As far as your nat lines. both nat and route lines appear as one line. I am not sure how that happened. Pls. make sure

sh run nat

only shows the following

nat (inside) 1 0.0.0.0 0.0.0.0

and sh run global

only shows the following

global (outside) 1 interface

These two lines do the overloading that you do in case of routers.

Re: NAT overload on asa 5520

Collin Clark — Tue, 08 Sep 2009 12:16:07 GMT

From the ASA can you ping 69.167.64.205? If it fails, do a SHOW ARP and see if you see a MAC to IP mapping. Let us know the results.

Re: NAT overload on asa 5520

shanemcanuff — Tue, 08 Sep 2009 13:06:07 GMT

thanks a lot guys I got it to work, I am going to try to pool 3 public IP I have to do NAT overload.

Re: NAT overload on asa 5520

shanemcanuff — Tue, 08 Sep 2009 13:23:03 GMT

can I overload the 3 public IP I have in the NAT rule?

Re: NAT overload on asa 5520

Collin Clark — Tue, 08 Sep 2009 13:26:14 GMT

You can only PAT one address. If you use 3 addresses, it will 1:1 NAT the first two addresses and then PAT the 3rd.

Re: NAT overload on asa 5520

shanemcanuff — Wed, 09 Sep 2009 20:34:43 GMT

Thanks a lot, I got it to work now. The major problem I was having was that I keep test the ping from the ASA, which keep failing when I test it from a system on the LAN I was able to access the internet.