06-07-2012 06:57 PM - edited 03-11-2019 04:16 PM
Could some security expert please help me understand icmp behavior for an ASA running 8.0 or 8.2?
My inside hosts (sitting behind the inside interface of ASA) can ping an external IP (on internet) . But when I ping that same external IP from the firewall, I don't get any reply.
Thanks,
Kashish
Solved! Go to Solution.
06-07-2012 08:05 PM
The reason why you can't ping from the ASA itself is because your ASA outside interface has private IP Address hence it's not routable on the Internet.
All your internal network has public IP assigned, therefore you can ping external host on the Internet.
06-07-2012 07:18 PM
Do you have "icmp" command configured on your ASA that might be blocking it.
You can configure:
icmp permit any outside
06-07-2012 07:48 PM
As per packet tracer, ping should be successful.
Phase: 1
Type: FLOW-LOOKUP
Subtype:
Result: ALLOW
Config:
Additional Information:
Found no matching flow, creating a new flow
Phase: 2
Type: ROUTE-LOOKUP
Subtype: input
Result: ALLOW
Config:
Additional Information:
in 0.0.0.0 0.0.0.0 outside
Phase: 3
Type: ACCESS-LIST
Subtype: log
Result: ALLOW
Config:
access-group citrix-dmz1-perm-all-tmp in interface citrix-dmz1
access-list citrix-dmz1-perm-all-tmp extended permit ip any any
Additional Information:
Phase: 4
Type: IP-OPTIONS
Subtype:
Result: ALLOW
Config:
Additional Information:
Phase: 5
Type: INSPECT
Subtype: np-inspect
Result: ALLOW
Config:
Additional Information:
Phase: 6
Type: FLOW-CREATION
Subtype:
Result: ALLOW
Config:
Additional Information:
New flow created with id 1746235146, packet dispatched to next module
Phase: 7
Type: ROUTE-LOOKUP
Subtype: output and adjacency
Result: ALLOW
Config:
Additional Information:
found next-hop 10.244.16.185 using egress ifc outside
adjacency Active
next-hop mac address 0015.63e8.d3d1 hits 12697093
Result:
input-interface: citrix-dmz1
input-status: up
input-line-status: up
output-interface: outside
output-status: up
output-line-status: up
Action: allow
Still only the inside hosts (sitting behind the inside interface of ASA) can ping an external IP (on internet) . But when I ping that same external IP from the firewall, I don't get any reply.
06-07-2012 07:49 PM
Can you please share your config. Thx
06-07-2012 08:02 PM
Hi Jennifer,
I have sent you the config file as a private message.
Thanks,
Ritika
06-07-2012 08:05 PM
The reason why you can't ping from the ASA itself is because your ASA outside interface has private IP Address hence it's not routable on the Internet.
All your internal network has public IP assigned, therefore you can ping external host on the Internet.
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