Inside to DMZ

[dr950]

I started to set up our PIX's DMZ. I am using NAT. To test it out before adding our servers I placed a PC on that network. I can get out to the internet, but I am not able to reach that PC from an internal machine. From our internal router I can ping the PC in the DMZ, but I cannot from an internal one. I can, however, reach the DMZ interface. Doing a trace from the router to the DMZ comp shows it is directly connected, tracing to the DMZ comp from an internal one times out at our router.
My question is, where should I start looking for possible solutions? Thanks for any help!

 

[gbiello]

Can you post a config? Here's a couple of lines I was missing the first time I set up a DMZ:

static (inside,dmz) 192.168.0.0 192.168.2.0 netmask 255.255.0.0
static (dmz,outside) 11.22.33.44 11.22.33.44 netmask 255.255.255.255
; 11.22.33.44 is a server in the DMZ

This example uses public IP's in the DMZ, and does not translate the IP's from the inside to public IP's when going into the DMZ. It leaves them as private.

-gbiello

 

[dr950]

Here's my config. Hopefully not edited too much, it's rather large.


PIX Version 6.1(1)
nameif ethernet0 outside security0
nameif ethernet1 inside security100
nameif ethernet2 dmz security50

fixup protocol ftp 21
fixup protocol http 80
fixup protocol h323 1720
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol sqlnet 1521
fixup protocol sip 5060
fixup protocol skinny 2000
no fixup protocol smtp 25


name 192.168.96.1 Testpc
access-list outside_access_in permit ip any 192.168.96.0 255.255.255.0

pager lines 24
logging on
logging timestamp
logging trap warnings
logging history warnings
logging host inside
interface ethernet0 10baset
interface ethernet1 10baset
interface ethernet2 auto
mtu outside 1500
mtu inside 1500
mtu dmz 1500
ip address outside xxx.xxx.6.17 255.255.255.248
ip address inside xxx.xxx.6.1 255.255.255.252
ip address dmz 192.168.96.250 255.255.255.0
ip audit info action alarm
ip audit attack action alarm

pdm location Testpc 255.255.255.255 dmz
pdm history enable
arp timeout 14400
global (outside) 1 interface
global (outside) 1 xxx.xx.6.18
global (outside) 1 xxx.xx.6.19
global (dmz) 1 interface
global (dmz) 1 192.168.96.251
nat (inside) 1 INET192Net 255.255.0.0 0 0
nat (dmz) 1 192.168.96.0 255.255.255.0 0 0

access-group outside_access_in in interface outside
access-group no_internet in interface inside
route outside 0.0.0.0 0.0.0.0 xxx.xx.6.20 1

timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323 0:0
p 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
terminal width 80

Thanks again

 

[gbiello]

Here's a couple of things that are a bit confusing:
1. From the inside subnet-mask (255.255.255.252) you only have a single device there.
2. It seems you have public IP's on the outside and inside, but private on the DMZ. Is this correct?

You have two global statements in the DMZ. I've never seen this. On the outside interface, you have three.

You still should need some static commands. Have a look at:

http://www.cisco.com/warp/public/110/mailserver_dmz.html

It has a good sample config.
-gbiello