Buy or Renew
Buy or Renew
Duo Security forums now LIVE! Get answers to all your Duo Security questions. Learn more
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 
cancel
Start a conversation
644
Views
0
Helpful
5
Replies

ASA5505 trouble with traffic going outside > inside

MikeyP
Level 1
Level 1

‎12-12-2017 01:44 PM - edited ‎02-21-2020 06:56 AM

As the title states I'm running into a bit of an issue getting my outside traffic in a different subnet to talk to my devices behind the ASA.  The background for this is that I want a test environment in my corporate environment which still has access to the internet.  Currently I do have access to the internet for my devices sitting behind the ASA.  The goal is to allow a select few users access behind the ASA to perform testing on various devices and prevent accidental traffic or unauthorized users from ever reaching that area of the network.

 

What I want to occur is network 10.3.9.30-48 to be able to communicate with 10.3.250.0/24 so I can remotely access devices in that network.  Any and all help would be appreciated.

 

How my network is setup

4500X with BGP which has a 10.3.0.0/16

4500X with vlan for 10.3.255.0/24 (this is my outside ASA interfaces network and NAT pool)

4500X is assigned 10.3.255.1

ASA is assigned 10.3.255.2 (outside)

ASA is assigned 10.3.250.1 (inside)

2960X running DHCP pool for 10.3.250.0/24 network behind ASA

5508 WLC behind 2960X

 

ASA config below

 

!
interface GigabitEthernet0/0
nameif outside
security-level 0
ip address 10.3.255.2 255.255.255.0
!
interface GigabitEthernet0/1
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet0/2
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet0/3
nameif inside
security-level 100
ip address 10.3.250.1 255.255.255.0
!
interface Management0/0
nameif management
security-level 100
ip address 10.3.254.1 255.255.255.0
management-only
!
ftp mode passive
clock timezone EST -5
clock summer-time EDT recurring
same-security-traffic permit inter-interface
same-security-traffic permit intra-interface
object-group network 10.100.100.0-30
object-group network 10.160.0.0-16
object-group network 10.3.250.0-100
object-group network 10.3.9.30-48
description Teams Reserved IP space
network-object host 10.3.9.30
network-object host 10.3.9.31
network-object host 10.3.9.32
network-object host 10.3.9.33
network-object host 10.3.9.34
network-object host 10.3.9.35
network-object host 10.3.9.36
network-object host 10.3.9.37
network-object host 10.3.9.38
network-object host 10.3.9.39
network-object host 10.3.9.40
network-object host 10.3.9.41
network-object host 10.3.9.42
network-object host 10.3.9.43
network-object host 10.3.9.44
network-object host 10.3.9.45
network-object host 10.3.9.46
network-object host 10.3.9.47
network-object host 10.3.9.48
object-group protocol TCPUDP
protocol-object udp
protocol-object tcp
access-list inside_access_out extended permit ip any any
access-list outside_nat_outbound extended permit ip object-group 10.3.9.30-48 10.3.250.0 255.255.255.0
access-list inside_access_in extended permit ip any any
access-list outside_access_in extended permit ip object-group 10.3.9.30-48 10.3.250.0 255.255.255.0
access-list outside_access_in extended permit object-group TCPUDP object-group 10.3.9.30-48 10.3.250.0 255.255.255.0
access-list outside_access_in extended permit tcp object-group 10.3.9.30-48 10.3.250.0 255.255.255.0 eq ssh
access-list outside_access_in extended permit icmp object-group 10.3.9.30-48 10.3.250.0 255.255.255.0
access-list outside_access_in extended permit ip 10.251.100.0 255.255.255.0 10.3.250.0 255.255.255.0
access-list outside_access_in extended permit ip 10.3.255.0 255.255.255.0 10.3.250.0 255.255.255.0
access-list inside_nat_outbound extended permit ip any any
pager lines 24
logging enable
logging buffered debugging
logging asdm informational
mtu outside 1500
mtu inside 1500
mtu management 1500
no failover
icmp unreachable rate-limit 1 burst-size 1
icmp permit any outside
icmp permit any inside
asdm image disk0:/asdm-762.bin
no asdm history enable
arp timeout 14400
nat-control
global (outside) 1 10.3.255.10-10.3.255.150 netmask 255.255.255.0
global (inside) 5 10.3.250.220-10.3.250.250 netmask 255.255.255.0
nat (outside) 5 access-list outside_nat_outbound outside
nat (outside) 5 10.3.9.47 255.255.255.255 outside
nat (inside) 1 access-list inside_nat_outbound
nat (inside) 1 0.0.0.0 0.0.0.0
static (inside,outside) 10.3.255.15 10.3.250.15 netmask 255.255.255.255
static (inside,outside) 10.3.255.20 10.3.250.20 netmask 255.255.255.255
static (inside,outside) 10.3.255.3 10.3.250.1 netmask 255.255.255.255
access-group outside_access_in in interface outside
access-group inside_access_in in interface inside
route outside 0.0.0.0 0.0.0.0 10.3.255.1 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
aaa authentication enable console LOCAL
aaa authentication http console LOCAL
aaa authentication ssh console LOCAL
aaa authorization command LOCAL
aaa authorization exec LOCAL
http server enable
http 192.168.1.0 255.255.255.0 management
http 0.0.0.0 0.0.0.0 inside
http 0.0.0.0 0.0.0.0 outside
http 10.3.254.0 255.255.255.0 management
http 10.3.9.0 255.255.255.192 outside
no snmp-server location
no snmp-server contact
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
telnet timeout 5
ssh 10.3.9.47 255.255.255.255 outside
ssh 10.3.8.0 255.255.248.0 outside
ssh timeout 5
ssh version 2
console timeout 0
threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
ntp server 10.251.2.145 source outside prefer
webvpn
anyconnect-essentials

!
class-map inspection_default
match default-inspection-traffic
!
!
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
message-length maximum 512
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
inspect ftp
inspect h323 h225
inspect h323 ras
inspect rsh
inspect rtsp
inspect esmtp
inspect sqlnet
inspect skinny
inspect sunrpc
inspect xdmcp
inspect sip
inspect netbios
inspect tftp
inspect ip-options
inspect icmp
inspect icmp error
!
service-policy global_policy global
prompt hostname context
no call-home reporting anonymous
Cryptochecksum:b3ddf99a79ca579fa1a525a5b905ad74
: end

Labels:
0 Helpful
5 Replies 5

Seb Rupik
VIP Alumni
VIP Alumni

‎12-13-2017 12:15 AM

Hi there,

What is the output from:

packet-tracer input outside rawip 10.3.9.30 0 10.3.250.1 detail

cheers,

Seb.

0 Helpful

MikeyP
Level 1
Level 1
In response to Seb Rupik

‎12-13-2017 08:28 AM

TESTLAB-ASA# packet-tracer input outside rawip 10.3.9.30 0 10.3.250.1 detail

Phase: 1
Type: ACCESS-LIST
Subtype:
Result: ALLOW
Config:
Implicit Rule
Additional Information:
Forward Flow based lookup yields rule:
in id=0x71446ed0, priority=1, domain=permit, deny=false
hits=57065, user_data=0x0, cs_id=0x0, l3_type=0x8
src mac=0000.0000.0000, mask=0000.0000.0000
dst mac=0000.0000.0000, mask=0100.0000.0000

Phase: 2
Type: ROUTE-LOOKUP
Subtype: input
Result: ALLOW
Config:
Additional Information:
in 10.3.250.1 255.255.255.255 identity

Phase: 3
Type: ACCESS-LIST
Subtype:
Result: DROP
Config:
Implicit Rule
Additional Information:
Forward Flow based lookup yields rule:
in id=0x714476f0, priority=0, domain=permit, deny=true
hits=25, user_data=0x9, cs_id=0x0, flags=0x1000, protocol=0
src ip=0.0.0.0, mask=0.0.0.0, port=0
dst ip=0.0.0.0, mask=0.0.0.0, port=0, dscp=0x0

Result:
input-interface: outside
input-status: up
input-line-status: up
output-interface: NP Identity Ifc
output-status: up
output-line-status: up
Action: drop
Drop-reason: (acl-drop) Flow is denied by configured rule

0 Helpful

Seb Rupik
VIP Alumni
VIP Alumni
In response to MikeyP

‎12-13-2017 12:07 PM

Sorry, should have got you to test against a destination host address not the ASA interface. Try this:

 

packet-tracer input outside rawip 10.3.9.30 0 10.3.250.2 detail
0 Helpful

MikeyP
Level 1
Level 1
In response to Seb Rupik

‎12-13-2017 12:11 PM - edited ‎12-13-2017 12:12 PM

TESTLAB-ASA# packet-tracer input outside rawip 10.3.9.30 0 10.3.250.2

Phase: 1
Type: ROUTE-LOOKUP
Subtype: input
Result: ALLOW
Config:
Additional Information:
in 10.3.250.0 255.255.255.0 inside

Phase: 2
Type: ACCESS-LIST
Subtype: log
Result: ALLOW
Config:
access-group outside_access_in in interface outside
access-list outside_access_in extended permit ip object-group 10.3.9.30-48 10.3.250.0 255.255.255.0
object-group network 10.3.9.30-48
description: 
network-object host 10.3.9.30
network-object host 10.3.9.31
network-object host 10.3.9.32
network-object host 10.3.9.33
network-object host 10.3.9.34
network-object host 10.3.9.35
network-object host 10.3.9.36
network-object host 10.3.9.37
network-object host 10.3.9.38
network-object host 10.3.9.39
network-object host 10.3.9.40
network-object host 10.3.9.41
network-object host 10.3.9.42
network-object host 10.3.9.43
network-object host 10.3.9.44
network-object host 10.3.9.45
network-object host 10.3.9.46
network-object host 10.3.9.47
network-object host 10.3.9.48
Additional Information:

Phase: 3
Type: IP-OPTIONS
Subtype:
Result: ALLOW
Config:
Additional Information:

Phase: 4
Type: NAT
Subtype:
Result: ALLOW
Config:
nat (outside) 5 access-list outside_nat_outbound outside
match ip outside host 10.3.9.30 inside 10.3.250.0 255.255.255.0
dynamic translation to pool 5 (10.3.250.220 - 10.3.250.250)
translate_hits = 4, untranslate_hits = 0
Additional Information:
Dynamic translate 10.3.9.30/0 to 10.3.250.238/0 using netmask 255.255.255.255

Phase: 5
Type: NAT
Subtype: host-limits
Result: ALLOW
Config:
nat (outside) 5 access-list outside_nat_outbound outside
match ip outside host 10.3.9.30 outside 10.3.250.0 255.255.255.0
dynamic translation to pool 5 (No matching global)
translate_hits = 0, untranslate_hits = 0
Additional Information:

Phase: 6
Type: NAT
Subtype: rpf-check
Result: DROP
Config:
nat (inside) 1 access-list inside_nat_outbound
match ip inside any outside any
dynamic translation to pool 1 (10.3.255.10 - 10.3.255.150)
translate_hits = 0, untranslate_hits = 0
Additional Information:

Result:
input-interface: outside
input-status: up
input-line-status: up
output-interface: inside
output-status: up
output-line-status: up
Action: drop
Drop-reason: (acl-drop) Flow is denied by configured rule

0 Helpful

Seb Rupik
VIP Alumni
VIP Alumni
In response to MikeyP

‎12-13-2017 12:47 PM

Ok so the rpf-check is showing that returned traffic is being NAT'd behind your outside interface.

I've had to dust off a ASA 8.2 config guide, but I think the following config should ensure that the return traffic (which matches the EXEMPT ACL) does not get NAT'd and the source IP remains unchanged:

!
access-list EXEMPT permit ip 10.3.250.0 255.255.255.0 object-group 10.3.9.30-48
!
nat (inside) 0 access-list EXEMPT
!

Maybe you should consider upgrading the ASA software? :)

 

cheers,

Seb.

0 Helpful
Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Customers Also Viewed These Support Documents
Review Cisco Networking products for a $25 gift card