12-10-2013 07:50 AM - edited 03-11-2019 08:15 PM
Hello,
I'm just putting together a basic ASA config and there seems to be an issue with NAT. I'm trying to ping a router past the outside interface 10.10.10.2 from an inside PC 10.101.61.10.
The ASA can ping it, can you see anything wrong with the below config?
ASA Version 8.4(2)
!
hostname ciscoasa
enable password 8Ry2YjIyt7RRXU24 encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
names
!
interface GigabitEthernet0
nameif outside
security-level 0
ip address 90.174.83.202 255.255.255.252
!
interface GigabitEthernet1
nameif inside
security-level 100
ip address 10.101.61.1 255.255.255.0
!
interface GigabitEthernet2
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet3
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet4
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet5
shutdown
no nameif
no security-level
no ip address
!
ftp mode passive
object network internal-10.101.61.0
subnet 10.101.61.0 255.255.255.0
object network Internal-0.0.0.0
subnet 0.0.0.0 0.0.0.0
access-list inside_access_in extended permit icmp any any
pager lines 24
logging enable
logging asdm informational
mtu outside 1500
mtu inside 1500
icmp unreachable rate-limit 1 burst-size 1
asdm image disk0:/asdm-714.bin
no asdm history enable
arp timeout 14400
!
object network Internal-0.0.0.0
nat (inside,outside) dynamic interface
access-group inside_access_in in interface inside
route outside 0.0.0.0 0.0.0.0 90.174.83.201 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
timeout floating-conn 0:00:00
dynamic-access-policy-record DfltAccessPolicy
user-identity default-domain LOCAL
aaa authentication enable console LOCAL
aaa authentication ssh console LOCAL
aaa authorization command LOCAL
aaa authorization exec LOCAL
http server enable
http 10.101.61.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart warmstart
telnet timeout 5
ssh 10.101.61.0 255.255.255.0 inside
ssh timeout 5
console timeout 0
dhcpd address 10.101.61.10-10.101.61.254 inside
dhcpd enable inside
!
threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
webvpn
username *** password *** encrypted privilege 15
!
!
prompt hostname context
no call-home reporting anonymous
call-home
profile CiscoTAC-1
no active
destination address http https://tools.cisco.com/its/service/oddce/services/DDCEService
destination address email callhome@cisco.com
destination transport-method http
subscribe-to-alert-group diagnostic
subscribe-to-alert-group environment
subscribe-to-alert-group inventory periodic monthly
subscribe-to-alert-group configuration periodic monthly
subscribe-to-alert-group telemetry periodic daily
crashinfo save disable
Cryptochecksum:4ce467cd868cc11bb408a997e3bf0fd2
: end
ciscoasa#
Thanks
Solved! Go to Solution.
12-10-2013 09:02 AM
Hi,
I would suggest adding a "permit ip any any" statement to the ACL as now its only allowing ICMP and nothing else. Or perhaps adding "permit ip 10.101.61.0 255.255.255.0 any"
You also seem to lack the default Policy Map configurations
class-map inspection_default
match default-inspection-traffic
policy-map type inspect dns preset_dns_map
parameters
message-length maximum 512
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
inspect sqlnet
inspect sunrpc
inspect tftp
inspect h323 h225
inspect h323 ras
inspect ip-options
inspect rtsp
inspect skinny
inspect pptp
inspect esmtp
inspect icmp
inspect icmp error
inspect ftp
!
service-policy global_policy global
You probably need the ICMP inspections configured (like above) for the Echo Reply to get back through the firewall.
That or allowing ICMP return messages like Echo Reply, Time Exceeded, Unreachable through the "outside" interface.
- Jouni
12-10-2013 09:04 AM
Hello Andrew,
So the 10.10.10.2 is on the outside interface, is that what you are saying??
If that is correct let's add
fixup protocol icmp and try one more time.
If the PC is on the inside I do not see a route to that device, you will need that and also a static translation to the outside interface.
Rate all of the helpful posts!!!
Regards,
Jcarvaja
Follow me on http://laguiadelnetworking.com
12-10-2013 09:02 AM
Hi,
I would suggest adding a "permit ip any any" statement to the ACL as now its only allowing ICMP and nothing else. Or perhaps adding "permit ip 10.101.61.0 255.255.255.0 any"
You also seem to lack the default Policy Map configurations
class-map inspection_default
match default-inspection-traffic
policy-map type inspect dns preset_dns_map
parameters
message-length maximum 512
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
inspect sqlnet
inspect sunrpc
inspect tftp
inspect h323 h225
inspect h323 ras
inspect ip-options
inspect rtsp
inspect skinny
inspect pptp
inspect esmtp
inspect icmp
inspect icmp error
inspect ftp
!
service-policy global_policy global
You probably need the ICMP inspections configured (like above) for the Echo Reply to get back through the firewall.
That or allowing ICMP return messages like Echo Reply, Time Exceeded, Unreachable through the "outside" interface.
- Jouni
12-10-2013 12:23 PM
Adding the default policy map also fixed it, would you mind explaining what this does?
12-10-2013 09:04 AM
Hello Andrew,
So the 10.10.10.2 is on the outside interface, is that what you are saying??
If that is correct let's add
fixup protocol icmp and try one more time.
If the PC is on the inside I do not see a route to that device, you will need that and also a static translation to the outside interface.
Rate all of the helpful posts!!!
Regards,
Jcarvaja
Follow me on http://laguiadelnetworking.com
12-10-2013 12:18 PM
Thanks that did it.
Do I need to add a default inspection policy too as I don't have one? What does this do?
Thanks
12-10-2013 12:25 PM
Hello Andrew,
I would recommend to add it.
Use the command
clear configure fixup to add the default policy map and then add the fixup protocol ICMP.
This will allow you to statefully inspect the specified traffic at a deep level (taking into consideration RFC standards, timeouts, packet-size, etc, etc, etc).
Now the thing with ICMP is that this protocol is not stateful as TCP is so when we enable this we basically let the ASA know save the ICMP sessions into your stateful session and monitor the returning traffic so get's allowed dynamically without the need of an ACL.
Then whenever we receice an ICMP echo reply for an echo request the session will be removed from the State table of the ASA.
Rate all of the helpful posts!!!
Regards,
Jcarvaja
Follow me on http://laguiadelnetworking.com
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