cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
6581
Views
0
Helpful
29
Replies

Allowing External Traffic on Cisco ASA

jweier_elys
Beginner
Beginner

Hi - I have a Cisco ASA and I'm really struggling with something very simple. I have an outside interface and I would like to allow traffic to hit the outside interface on TCP Port 81 and get NAT'd to a private IP on a webserver. I believe I have the NAT piece of the equation solved but the ACL is processed first and I can't figure out the ACL for the life of me. Here's what I have:

 

On the outside interface, I created an incoming rule with any source, any destination and a service of TCP Port 81. However, when I run a Packet Tracer from any public IP to the IP of the outside interface on Port 81 the packet is dropped via an implicit rule. 

 

I'm running ASA 9.9, thoughts?PacketTracer.png

 

Rule.pngInterfaces.pngPacketTracer.png

29 Replies 29

can you test this.

 

object network SERVER
 host 10.1.1.79
!
nat (inside,outside) 1 source static SERVER interface service Port80 Port81

!

no access-list outside_access_in extended permit tcp any host 10.1.1.79 range 81 81
no nat (inside,outside) source static any interface service Port80 Port81

!

access-list outside_access_in extended permit tcp any object SERVER eq 80

access-group outside_access_in in interface outside

!

 

(OR)

as i stated in my earlier post

object network SERVER
 host 10.1.1.79
 nat (inside,outside) static interface service tcp 80 81
!
access-list outside_in permit tcp any host 10.1.1.79 eq 80
access-group outside_in in interface outside

!

no access-list outside_access_in extended permit tcp any host 10.1.1.79 range 81 81
no nat (inside,outside) source static any interface service Port80 Port81

please do not forget to rate.

 

object network SERVER
 host 10.1.1.79
!
nat (inside,outside) 1 source static SERVER interface service Port80 Port81

!

no access-list outside_access_in extended permit tcp any host 10.1.1.79 range 81 81
no nat (inside,outside) source static any interface service Port80 Port81

 

 

Apply these config as mentioned above it will work

please do not forget to rate.

Sheraz.Salim
VIP Advisor VIP Advisor
VIP Advisor

I have lab this up. your configuration were wrong. here is the right configuration.

 

object network SERVER
 host 10.1.1.79

 !

object service CUSTOM80
 service tcp source eq 80
!
object service CUSTOM81
 service tcp source eq 81
!
nat (inside,outside) source static SERVER interface service CUSTOM80 CUSTOM81
!
access-list outside_access_in extended permit tcp any object SERVER eq 80
access-group outside_access_in in interface outside

!

packet-tracer input outside tcp 8.8.8.8 1234 96.89.224.197 81

 

 

please do not forget to rate.

Hi - I appreciate the help. Unfortunately, this didn't seem to work either. Although, this time the packet-tracer hits the NAT and gets through it but is stopped by the ACL. I've also re-attached the config.

 

ciscoasa# packet-tracer input outside tcp 8.8.8.8 1234 96.89.224.197 81

Phase: 1
Type: ROUTE-LOOKUP
Subtype: Resolve Egress Interface
Result: ALLOW
Config:
Additional Information:
found next-hop 96.89.224.197 using egress ifc identity

Phase: 2
Type: NAT
Subtype: per-session
Result: ALLOW
Config:
Additional Information:

Phase: 3
Type: ACCESS-LIST
Subtype:
Result: DROP
Config:
Implicit Rule
Additional Information:

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

can you try this and give us the output. the reason i said in our access-list we allow www (80) not 81

 

 

ciscoasa# packet-tracer input outside tcp 8.8.8.8 1234 96.89.224.197 80

please do not forget to rate.

See below:

 

ciscoasa(config)# packet-tracer input outside tcp 8.8.8.8 1234 96.89.224.197 80

Phase: 1
Type: ROUTE-LOOKUP
Subtype: Resolve Egress Interface
Result: ALLOW
Config:
Additional Information:
found next-hop 96.89.224.197 using egress ifc identity

Phase: 2
Type: NAT
Subtype: per-session
Result: ALLOW
Config:
Additional Information:

Phase: 3
Type: ACCESS-LIST
Subtype:
Result: DROP
Config:
Implicit Rule
Additional Information:

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

I can reach you on your public ip address 96.89.224.197 80

 

80.PNG

!

 

please do not forget to rate.

Hey - Yea, but I think that is https, not http. If I'm in a browser and go to https I'm able to login to AnyConnect. However, if I go on http port 80 I don't get AnyConnect or the website I'm expecting. I also don't get anything when I browse on http port 81.

can you take these rules off and test it. by taking these rule off will not impact/discount your session.

!

no access-list inside_access_in_1 extended permit object-group DM_INLINE_PROTOCOL_2 any
no access-list inside_access_out_1 extended permit object-group DM_INLINE_PROTOCOL_3 any any

no access-group outside_access_out out interface outside
no access-group inside_access_in_1 in interface inside

!

packet tracert 8.8.8.8 12345 x.x.x.x.x 80 det

 

please do not forget to rate.

Looks like it's still dropped by the ACL:

 

ciscoasa# packet-tracer input outside tcp 8.8.8.8 1234 96.89.224.197 80

Phase: 1
Type: ROUTE-LOOKUP
Subtype: Resolve Egress Interface
Result: ALLOW
Config:
Additional Information:
found next-hop 96.89.224.197 using egress ifc identity

Phase: 2
Type: NAT
Subtype: per-session
Result: ALLOW
Config:
Additional Information:

Phase: 3
Type: ACCESS-LIST
Subtype:
Result: DROP
Config:
Implicit Rule
Additional Information:

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

sorry for get back late. I did look into this and test this. take the old rules off and apply theses one

!

object network SERVER
 host 10.1.1.79

 !

object service CUSTOM80
 service tcp source eq 80
!
object service CUSTOM81
 service tcp source eq 81
!

no nat (inside,outside) source static SERVER interface service CUSTOM80 CUSTOM81
nat (inside,outside) source static SERVER interface service CUSTOM81 CUSTOM80
!

no access-list outside_access_in extended permit tcp any object SERVER eq 80
access-list outside_access_in extended permit tcp any object SERVER eq 81
access-group outside_access_in in interface outside

!

packet-tracer input outside tcp 8.8.8.8 81 96.89.224.197 80

!

 

please let me know if any issue. I have tested these rule and they working.

 

please do not forget to rate.

Hi - Unfortunately it still doesn't work. I've attached the latest packet tracer below. I also tried flipping the NAT policies like we talk about yesterday but no luck.

 

ciscoasa(config)# packet-tracer input outside tcp 8.8.8.8 81 96.89.224.197 80

Phase: 1
Type: ROUTE-LOOKUP
Subtype: Resolve Egress Interface
Result: ALLOW
Config:
Additional Information:
found next-hop 96.89.224.197 using egress ifc identity

Phase: 2
Type: NAT
Subtype: per-session
Result: ALLOW
Config:
Additional Information:

Phase: 3
Type: ACCESS-LIST
Subtype:
Result: DROP
Config:
Implicit Rule
Additional Information:

Result:
input-interface: outside

 

 

ciscoasa(config)# show nat
Manual NAT Policies (Section 1)
1 (inside) to (outside) source static Utility1 interface service CUSTOM80 CUSTOM81
translate_hits = 0, untranslate_hits = 0
2 (wlan) to (outside) source dynamic obj_any interface
translate_hits = 4143583, untranslate_hits = 365981
3 (inside) to (outside) source static any any destination static NETWORK_OBJ_10.1.2.0_26 NETWORK_OBJ_10.1.2.0_26 no-proxy-arp route-lookup
translate_hits = 0, untranslate_hits = 0

Auto NAT Policies (Section 2)
1 (any) to (outside) source dynamic obj_any interface
translate_hits = 48275, untranslate_hits = 3822

Manual NAT Policies (Section 3)
1 (inside) to (outside) source dynamic obj_any interface
translate_hits = 0, untranslate_hits = 0

 

 

you have not change the nat rules put in this order

 

no nat (inside,outside) source static SERVER interface service CUSTOM80 CUSTOM81
nat (inside,outside) source static SERVER interface service CUSTOM81 CUSTOM80
!

no access-list outside_access_in extended permit tcp any object SERVER eq 80
access-list outside_access_in extended permit tcp any object SERVER eq 81
access-group outside_access_in in interface outside

!

packet-tracer input outside tcp 8.8.8.8 81 96.89.224.197 80

====================================================================

This is the config you just put them earlier change them as describe above. I test them in lab enviroment you should be ok now.

Manual NAT Policies (Section 1)
1 (inside) to (outside) source static Utility1 interface service CUSTOM80 CUSTOM81

please do not forget to rate.

Looks like we got it!

 

I had to modify your latest changes a little bit:

 

From:

nat (inside,outside) source static SERVER interface service CUSTOM81 CUSTOM80

 

To:

nat (inside,outside) 1 source static SERVER interface service CUSTOM81 CUSTOM80

 

That combined with the ACLs worked! So to put it all in one place:

 

object network Utility1
host 10.1.1.79

!

access-list outside_access_in extended permit tcp any object Utility1 eq 81

!

nat (inside,outside) 1 source static Utility1 interface service CUSTOM81 CUSTOM80

!

access-group outside_access_in in interface outside

 

Thank you so much for your help!

 

Thank you.

please do not forget to rate.
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: