Can't access the DMZ servers using Public IP

Posted on 2006-07-03
Last Modified: 2011-09-20
Hi All,

Here is a problem i'm facing, but not sure why this happening. It would be helpful if you can help.

Current config;

Internet --- Router --- PIX
                                   ------ DMZ --- WebServer
                                   ------ Inside --- Workstation

Out Side of the Pix Ip:
DMZ Range -, Ip of the web server
Insize Range -, ip of the workstation

PAT is enabled on the inside interface so that the clients can use the internet and DMZ servers
PAT is also enabled on the DMZ  interface on DMZ can reach outside

I have static NAT entry to the webserver
static (dmz1,outside) permit tcp any host

and have a acess-list to permit web traffice and, this access it listed on the access-group of the ouside interface.

I can access the server from the outside. i can access the server from inside network using the ip address of the DMZ.

But when i try to access the web server from the inside or DMZ network using the ip in the browser it is getting unreachable. Is is creating a problem for my web application which is redirecting differnt part of the application using the url. How can i resolve this ?

Here is the running config of the pix;
PIX Version 6.3(5)
interface ethernet0 auto
interface ethernet1 auto
interface ethernet2 auto
nameif ethernet0 outside security0
nameif ethernet1 inside security100
nameif ethernet2 dmz1 security10
fixup protocol dns maximum-length 512
fixup protocol ftp 21
fixup protocol h323 h225 1720
fixup protocol h323 ras 1718-1719
fixup protocol http 80
fixup protocol ils 389
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol sip 5060
fixup protocol sip udp 5060
fixup protocol skinny 2000
fixup protocol smtp 25
fixup protocol sqlnet 1521
fixup protocol tftp 69
access-list aclout1 permit tcp any host eq www
pager lines 24
icmp permit any outside
icmp permit host outside
icmp permit any inside
icmp permit host inside
icmp permit any dmz1
icmp permit host dmz1
mtu outside 1500
mtu inside 1500
mtu dmz1 1500
ip address outside
ip address inside
ip address dmz1
ip audit info action alarm
ip audit attack action alarm
pdm location inside
pdm location inside
pdm history enable
arp timeout 14400
global (outside) 10 interface
global (dmz1) 10 interface
nat (inside) 10 0 0
nat (dmz1) 10 0 0
static (dmz1,outside) netmask 0 0
access-group aclout1 in interface outside
route outside 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h225 1:00:00
timeout h323 0:05:00 mgcp 0:05:00 sip 0:30:00 sip_media 0:02:00
timeout sip-disconnect 0:02:00 sip-invite 0:03:00
timeout uauth 0:05:00 absolute
aaa-server TACACS+ protocol tacacs+
aaa-server TACACS+ max-failed-attempts 3
aaa-server TACACS+ deadtime 10
aaa-server RADIUS protocol radius
aaa-server RADIUS max-failed-attempts 3
aaa-server RADIUS deadtime 10
aaa-server LOCAL protocol local
http server enable
http inside
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
telnet timeout 5
ssh timeout 5
console timeout 0
terminal width 80
--------------------------End Pix Config


Question by:tssiva
LVL 13

Expert Comment

Comment Utility
static (dmz1,outside) netmask 0 0
access-list aclout1 permit tcp any host eq smtp
LVL 79

Accepted Solution

lrmoore earned 500 total points
Comment Utility
>I can access the server from the outside. i can access the server from inside network using the ip address of the DMZ.
This indicates that your configuration for statics and access-lists are correct

>But when i try to access the web server from the inside or DMZ network using the ip in the browser it is getting unreachable.
That is correct. This is pure design principles of the PIX and order of packet flow and nat

>How can i resolve this ?
You can't. You can never access natted public IP's from the inside directly.

HOWEVER, there is some saving grace in that you are trying to go from inside to DMZ and the natted host is on the DMZ. Depending on the OS version of your PIX, you may be able to use ALIAS command to perform dnat:

Understanding the alias Command for the Cisco Secure PIX Firewall

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