PIX configuration I do not understand, but it works

[marqo]

Hi everybosy,
I'm writing from Italy because I am not able to reconfigure my PIX 501 in order to work with my new provider's router. I'm a newbie, so I apologize for wasting yur time with a maybe silly doubt.
Here is the configuration my PIX now uses and everything works:

PIX Version 6.1(2)
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password GJRRi4nf8ktKiYyH encrypted
passwd dNjmOrWCBcmpp1Fz encrypted
hostname pixfirewall
fixup protocol ftp 21
fixup protocol http 80
fixup protocol h323 1720
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol smtp 25
fixup protocol sqlnet 1521
fixup protocol sip 5060
fixup protocol skinny 2000
names
pager lines 24
interface ethernet0 10baset
interface ethernet1 10full
mtu outside 1500
mtu inside 1500
ip address outside 192.168.242.2 255.255.255.0
ip address inside 192.168.242.1 255.255.0.0
ip audit info action alarm
ip audit attack action alarm
pdm logging informational 100
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 1 192.168.242.0 255.255.255.0 0 0
route outside 0.0.0.0 0.0.0.0 192.168.242.1 1
timeout xlate 0:05:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323 0:05:00 sip 0:30:00 sip_media 0:02:00
timeout uauth 0:05:00 absolute
aaa-server TACACS+ protocol tacacs+
aaa-server RADIUS protocol radius
http server enable
http 192.168.1.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
no sysopt route dnat
telnet 192.168.242.0 255.255.255.0 inside
telnet timeout 5
ssh timeout 5
dhcpd lease 3600
dhcpd ping_timeout 750
dhcpd auto_config outside
terminal width 80

Now I have a new router with address 212.31.239.209 on its Ethernet interface.
I tried various modifications to my configuration, such as:

ip address outside 212.31.239.209 255.255.255.240
.
.
.
route outside 0.0.0.0 0.0.0.0 212.31.239.209 1

but it does not work, do I have to change the line:

global (outside) 1 interface
(which I am not sure wath really does written in this way)
in order to be able to navigate the Internet from my LAN (192.168.242.XXX)?
Any piece of information will be really appreciated.
Thanks in advance for your time and attention.
Marco

 

[TigreRouge]

Hi Margo,

212.31.239.209 is the address of your new router?
What is the range of public addresses (255.255.255.240) you have?

If for example, the address of your router is 212.31.239.209 and the mask is 255.255.255.240, you have to give to your outside interface of your PIX an address in this network.
For example : 212.31.239.210 if this address is available.

Then, you have to change the configuration of your PIX:

replace
ip address outside 192.168.242.2 255.255.255.0
by
ip address outside 212.31.239.210 255.255.255.240

replace
route outside 0.0.0.0 0.0.0.0 192.168.242.1 1
by
route outside 0.0.0.0 0.0.0.0 212.31.239.210 1

You can let the line "global", it's OK, this line indicates that your inside network is hidden behind the interface address (outside interface) when it navigates the Internet.

Let me know if it helps!