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Cisco ASA 8.3 - Dynamic PAT - cannot ping internet address

Last Modified: 2012-05-12
I'm reconfiguring our Meeting Firewall after migrating from a Cisco PIX 525 to a ASA 5505 (8.3).
I've reconfigured the firewall following Cisco guidelines on the new NAT rules. here following find the relevant part of the config:

object network obj_any
object network ExternalServer
object network InternalServer
object network Symposium
object network DynSymposium
object network obj-
object network obj-
access-list inside_access_in extended permit ip any any
access-list outside_access_in extended permit ip any any
access-list OUTSIDE_IN_ACL extended permit icmp any any echo-reply
access-list OUTSIDE_IN_ACL extended permit icmp any any time-exceeded
pager lines 24
logging enable
logging asdm informational
mtu inside 1500
mtu outside 1500
mtu dmz 1500
no failover
icmp unreachable rate-limit 1 burst-size 1
asdm image disk0:/asdm-645-205.bin
no asdm history enable
arp timeout 14400
object network InternalServer
 nat (inside,outside) static ExternalServer
object network obj-
 nat (inside,outside) dynamic
object network obj-
 nat (dmz,outside) dynamic DynSymposium
access-group inside_access_in in interface inside
access-group OUTSIDE_IN_ACL in interface outside
route outside 1

From the server (static NAT) everything works fine.

From the PAT network (
If I configure the PAT to be a public IP =  nat (inside,outside) dynamic
I cannot ping external websites (e.g.: Google)
I can ping always the internal interface (gateway)

If I configure the PAT to use the outside interface =   nat (inside,outside) dynamic interface
I can ping and tracert any external website
I can ping always the internal interface (gateway)

I should probably say that I'm currently connecting from China (some downtime could be due to the infrastructure)

Do you see anything wrong with my configuration?
Is it normal that I cannot ping external websites when I configure a Dynamic PAT?

P.S.: I have attached the full FW configuration (I removed only few lines)

Roberto. ASA-conf.txt
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