Can't route out PIX

Posted on 2006-06-25
Last Modified: 2013-11-16
  I have a PIX 501 hooked up to a Motorola Surfboard Cable modem for Comcast.
I cannot get traffic to route from the inside to the outside through the Pix. While consoled into the Pix,  I can ping out the outside interface to several internet IPs. But I cannot get any traffic to go from the internal network to the internet. I have erased the config several times and configured it by hand and via PDM. Whay am I missing here.

PIX Version 6.3(5)
interface ethernet0 100full
interface ethernet1 100full
nameif ethernet0 outside security0
nameif ethernet1 inside security100
hostname CiscoPIX
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 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 inside_access_in permit ip any any
pager lines 24
mtu outside 1500
mtu inside 1500
ip address outside dhcp setroute
ip address inside
ip audit info action alarm
ip audit attack action alarm
pdm location inside
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 1 0 0
access-group inside_access_in in interface inside
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 XXXXXXXXX
no snmp-server enable traps
floodguard enable
telnet timeout 5
ssh inside
ssh timeout 5
console timeout 0
terminal width 80
: end
Question by:johnelayn

Assisted Solution

martyboy earned 50 total points
ID: 16982352
You dont need your accesslist, you can remove that statement.

What does sh interface say?
Have you checked the log?


Expert Comment

ID: 16982763
I take it you are statically assigning inside host addresses?

Is this a DNS issue you are seeing? Have you specified a DNS server? Can you ping web servers?

If you want the CISCO PIX to be a DHCP Server and assign DNS, uses these command line examples;

dhcpd address inside         <--- Sets the PIX to be a DHCP using the address range to

dhcpd dns            <---- Sets 2x DNS servers as specified.


Expert Comment

ID: 16982990
and btw you cant by deafult use ping from hosts behind your inside interface. You need to configure the pix to allow that.
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LVL 79

Assisted Solution

lrmoore earned 100 total points
ID: 16983418
remove the acl from the inside interface. It is not needed:

no access-group inside_access_in in interface inside

Taking martyboy's comment a bit further - allow icmp packets in
 access-list icmp permit icmp any any
 access-group icmp in interface outside

Now you can ping from an inside host, assuming that the inside host has as the default gateway.


Expert Comment

ID: 16990005
icmp permit|deny [host] src_addr [src_mask] [type] int_name

enable icmp in the box...


Accepted Solution

Jaedub earned 100 total points
ID: 17043539
Your config is fine.  Remove the access-list as mentioned above.  Power cycle your comcast modem and let it come up for 30-60 seconds.  Then power up your pix and wait for 60-90 seconds.  

Open your browser and enter
See what opens up. If that works, your traffic is flowing. If not, let us know.  (we are assuming that your computer has a proper address, subnet mask and gateway of
If you have a properly configured DNS entry, you should be able to open

If you want DHCP services, the proper way to configure for your setup is:

dhcpd address inside
dhcpd auto_config outside
dhcpd enable inside

Let us know.....


Author Comment

ID: 17046625
Thanks guys, it works fine now.

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