2

I am needing help in the configuration process of my Cisco ASA 5510. I have set up 4 Cisco ASA interconnected together via a big LAN. Each Cisco ASA has 3 or 4 LANs attached to them. The IP routing part is taken care of by OSPF. My problem is on another level.

A computer connected to one of the LANs attached to an ASA has no problem communicating with the outside world. The outside world being anything "after" the ASA. My problem is that I am completely unable to have them communicate with another LAN connected to the same ASA. To rephrase this, I am unable to send traffic from one interface of a given ASA to another interface of the same ASA.

My configuration is the following :

!
hostname Fuji
!
interface Ethernet0/0
 speed 100
 duplex full
 nameif outside
 security-level 0
 ip address 10.0.0.2 255.255.255.0  no shutdown
!
interface Ethernet0/1
 speed 100
 duplex full
 nameif cs4  no shutdown
 security-level 100
 ip address 10.1.4.1 255.255.255.0
! 
interface Ethernet0/2  
speed 100  
duplex full  
no shutdown 
!
interface Ethernet0/2.15  vlan 15
 nameif cs5
 security-level 100
 ip address 10.1.5.1 255.255.255.0
!
interface Ethernet0/2.16  vlan 16
 nameif cs6
 security-level 100
 ip address 10.1.6.1 255.255.255.0
!
interface Management0/0
 speed 100
 duplex full
 nameif management
 security-level 100
 ip address 10.6.0.252 255.255.255.0
!
access-list nat_cs4 extended permit ip 10.1.4.0 255.255.255.0 any
access-list acl_cs4 extended permit ip 10.1.4.0 255.255.255.0 any
access-list nat_cs5 extended permit ip 10.1.5.0 255.255.255.0 any
access-list acl_cs5 extended permit ip 10.1.5.0 255.255.255.0 any
access-list nat_cs6 extended permit ip 10.1.6.0 255.255.255.0 any
access-list acl_cs6 extended permit ip 10.1.6.0 255.255.255.0 any
!
access-list nat_outside extended permit ip any any
access-list acl_outside extended permit ip any 10.1.4.0 255.255.255.0
access-list acl_outside extended permit ip any 10.1.5.0 255.255.255.0
access-list acl_outside extended permit ip any 10.1.6.0 255.255.255.0
!
nat (outside) 0 access-list nat_outside
nat (cs4) 0 access-list nat_cs4
nat (cs5) 0 access-list nat_cs5
nat (cs6) 0 access-list nat_cs6
!
static (outside,cs4) 0.0.0.0 0.0.0.0 netmask 0.0.0.0
static (outside,cs5) 0.0.0.0 0.0.0.0 netmask 0.0.0.0
static (outside,cs6) 0.0.0.0 0.0.0.0 netmask 0.0.0.0
!
static (cs4,outside) 10.1.4.0 10.1.4.0 netmask 255.255.255.0
static (cs4,cs5) 10.1.4.0 10.1.4.0 netmask 255.255.255.0
static (cs4,cs6) 10.1.4.0 10.1.4.0 netmask 255.255.255.0
!
static (cs5,outside) 10.1.5.0 10.1.5.0 netmask 255.255.255.0
static (cs5,cs4) 10.1.5.0 10.1.5.0 netmask 255.255.255.0
static (cs5,cs6) 10.1.5.0 10.1.5.0 netmask 255.255.255.0
!
static (cs6,outside) 10.1.6.0 10.1.6.0 netmask 255.255.255.0
static (cs6,cs4) 10.1.6.0 10.1.6.0 netmask 255.255.255.0
static (cs6,cs5) 10.1.6.0 10.1.6.0 netmask 255.255.255.0
!
access-group acl_outside in interface outside
access-group acl_cs4 in interface cs4
access-group acl_cs5 in interface cs5
access-group acl_cs6 in interface cs6
!
router ospf 1
 network 10.0.0.0 255.255.255.0 area 1
 network 10.1.4.0 255.255.255.0 area 1
 network 10.1.5.0 255.255.255.0 area 1
 network 10.1.6.0 255.255.255.0 area 1
 log-adj-changes
!

There is nothing really complicated in this configuration. It just NATs from one interface to another and that's it. I have tried enabling same-security-traffic permit inter-interface but that doesn't help.

I therefore must be missing something a little bit more complicated. Does anyone know why I cannot foward traffic from one interface to another ?

Thank you in advance for your help,

Antoine

Antoine Benkemoun
  • 7,314
  • 3
  • 41
  • 60

2 Answers2

1

Add same-security-traffic permit inter-interface in your configuration Interface with the same security level can't communicate with each other without this command.

radius
  • 9,545
  • 23
  • 45
1

I finally got this fixed ! I was doing way too much NAT. I deactivated nat-control, allowed same-security-level communication and got rid of most of the Nat stuff.

Below is my working config.

! 
hostname Fuji 
! 
interface Ethernet0/0 
 speed 100 
 duplex full 
 nameif outside 
 security-level 0 
 ip address 10.0.0.2 255.255.255.0
 no shutdown 
! 
interface Ethernet0/1 
 speed 100 
 duplex full 
 nameif cs4
 no shutdown 
 security-level 100 
 ip address 10.1.4.1 255.255.255.0 
!
interface Ethernet0/2
 speed 100
 duplex full
 no shutdown
! 
interface Ethernet0/2.15
 vlan 15 
 nameif cs5 
 security-level 100 
 ip address 10.1.5.1 255.255.255.0 
! 
interface Ethernet0/2.16
 vlan 16 
 nameif cs6 
 security-level 100 
 ip address 10.1.6.1 255.255.255.0 
! 
interface Management0/0 
 speed 100 
 duplex full 
 nameif management 
 security-level 100 
 ip address 10.6.0.252 255.255.255.0 
!
same-security-traffic permit inter-interface 
no nat-control
! 
access-list acl_cs4 extended permit ip 10.1.4.0 255.255.255.0 any 
access-list acl_cs5 extended permit ip 10.1.5.0 255.255.255.0 any 
access-list acl_cs6 extended permit ip 10.1.6.0 255.255.255.0 any 
! 
access-list acl_outside extended permit ip any 10.1.4.0 255.255.255.0 
access-list acl_outside extended permit ip any 10.1.5.0 255.255.255.0 
access-list acl_outside extended permit ip any 10.1.6.0 255.255.255.0 
! 
static (outside,cs4) 0.0.0.0 0.0.0.0 netmask 0.0.0.0 
static (outside,cs5) 0.0.0.0 0.0.0.0 netmask 0.0.0.0 
static (outside,cs6) 0.0.0.0 0.0.0.0 netmask 0.0.0.0 
! 
access-group acl_outside in interface outside 
access-group acl_cs4 in interface cs4 
access-group acl_cs5 in interface cs5 
access-group acl_cs6 in interface cs6 
! 
router ospf 1 
 network 10.0.0.0 255.255.255.0 area 1 
 network 10.1.4.0 255.255.255.0 area 1 
 network 10.1.5.0 255.255.255.0 area 1 
 network 10.1.6.0 255.255.255.0 area 1 
 log-adj-changes 
!
Antoine Benkemoun
  • 7,314
  • 3
  • 41
  • 60