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I have recently inherited a network with a Cisco ASA (running version 8.2).

I am trying to configure it to allow communication between two interfaces configured with the same security level (DMZ-DMZ)

"same-security-traffic permit inter-interface" has been set, but hosts are unable to communicate between the interfaces. I am assuming that some NAT settings are causing my issue. Below is my running config:

ASA Version 8.2(3) 
hostname asa
enable password XXXXXXXX encrypted
passwd XXXXXXXX encrypted
interface Ethernet0/0
 switchport access vlan 400
interface Ethernet0/1
 switchport access vlan 400
interface Ethernet0/2
 switchport access vlan 420
interface Ethernet0/3
 switchport access vlan 420
interface Ethernet0/4
 switchport access vlan 450
interface Ethernet0/5
 switchport access vlan 450
interface Ethernet0/6
 switchport access vlan 500
interface Ethernet0/7
 switchport access vlan 500
interface Vlan400
 nameif outside
 security-level 0
 ip address XX.XX.XX.10 
interface Vlan420
 nameif public
 security-level 20
 ip address 
interface Vlan450
 nameif dmz
 security-level 50
 ip address 
interface Vlan500
 nameif inside
 security-level 100
 ip address 
ftp mode passive
clock timezone JST 9
same-security-traffic permit inter-interface
same-security-traffic permit intra-interface
object-group network DM_INLINE_NETWORK_1
 network-object host XX.XX.XX.11
 network-object host XX.XX.XX.13
object-group service ssh_2220 tcp
 port-object eq 2220
object-group service ssh_2251 tcp
 port-object eq 2251
object-group service ssh_2229 tcp
 port-object eq 2229
object-group service ssh_2210 tcp
 port-object eq 2210
object-group service DM_INLINE_TCP_1 tcp
 group-object ssh_2210
 group-object ssh_2220
object-group service zabbix tcp
 port-object range 10050 10051
object-group service DM_INLINE_TCP_2 tcp
 port-object eq www
 group-object zabbix
object-group protocol TCPUDP
 protocol-object udp
 protocol-object tcp
object-group service http_8029 tcp
 port-object eq 8029
object-group network DM_INLINE_NETWORK_2
 network-object host
 network-object host
 network-object host
object-group service imaps_993 tcp
 description Secure IMAP
 port-object eq 993
object-group service public_wifi_group
 description Service allowed on the Public Wifi Group. Allows Web and Email.
 service-object tcp-udp eq domain 
 service-object tcp-udp eq www 
 service-object tcp eq https 
 service-object tcp-udp eq 993 
 service-object tcp eq imap4 
 service-object tcp eq 587 
 service-object tcp eq pop3 
 service-object tcp eq smtp 
access-list outside_access_in remark http traffic from outside
access-list outside_access_in extended permit tcp any object-group DM_INLINE_NETWORK_1 eq www 
access-list outside_access_in remark ssh from outside to web1
access-list outside_access_in extended permit tcp any host XX.XX.XX.11 object-group ssh_2251 
access-list outside_access_in remark ssh from outside to penguin
access-list outside_access_in extended permit tcp any host XX.XX.XX.10 object-group ssh_2229 
access-list outside_access_in remark http from outside to penguin
access-list outside_access_in extended permit tcp any host XX.XX.XX.10 object-group http_8029 
access-list outside_access_in remark ssh from outside to internal hosts
access-list outside_access_in extended permit tcp any host XX.XX.XX.13 object-group DM_INLINE_TCP_1 
access-list outside_access_in remark dns service to internal host
access-list outside_access_in extended permit object-group TCPUDP any host XX.XX.XX.13 eq domain 
access-list dmz_access_in extended permit ip any 
access-list dmz_access_in extended permit tcp any host object-group DM_INLINE_TCP_2 
access-list public_access_in remark Web access to DMZ websites
access-list public_access_in extended permit object-group TCPUDP any object-group DM_INLINE_NETWORK_2 eq www 
access-list public_access_in remark General web access. (HTTP, DNS & ICMP and  Email)
access-list public_access_in extended permit object-group public_wifi_group any any 
pager lines 24
logging enable
logging asdm informational
mtu outside 1500
mtu public 1500
mtu dmz 1500
mtu inside 1500
no failover
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 60
global (outside) 1 interface
global (dmz) 2 interface
nat (public) 1
nat (dmz) 1
nat (inside) 1
static (inside,outside) tcp interface 2229 2229 netmask 
static (inside,outside) tcp interface 8029 www netmask 
static (dmz,outside) XX.XX.XX.13 netmask dns 
static (dmz,outside) XX.XX.XX.11 netmask dns 
static (dmz,inside) netmask 
static (dmz,public) netmask dns 
static (dmz,public) netmask dns 
static (inside,dmz) netmask dns 
access-group outside_access_in in interface outside
access-group public_access_in in interface public
access-group dmz_access_in in interface dmz
route outside XX.XX.XX.9 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
dynamic-access-policy-record DfltAccessPolicy
http server enable
http inside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
telnet timeout 5
ssh inside
ssh timeout 20
console timeout 0
dhcpd dns
dhcpd auto_config outside
dhcpd address public
dhcpd enable public
dhcpd address inside
dhcpd enable inside

threat-detection basic-threat
threat-detection statistics host
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
ntp server source public

class-map inspection_default
 match default-inspection-traffic
policy-map type inspect dns preset_dns_map
  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 ip-options 
  inspect netbios 
  inspect rsh 
  inspect rtsp 
  inspect skinny  
  inspect esmtp 
  inspect sqlnet 
  inspect sunrpc 
  inspect tftp 
  inspect sip  
  inspect xdmcp 
share|improve this question
That's only for routed traffic, like if you had two vlan interfaces configured with an identical security-level. Firewall rules are not applied to switched traffic - this is a 5505, right? Are you not able to get switched traffic between ports 4 and 5? – Shane Madden Jan 31 '12 at 4:05
I can switch traffic from Port 5 to 4, but not from 4 to 5. I believe it's down to some of the NAT rules associated with the IP's on port 4 i.e. from IP (on port 5) I can connect to on port 4. I cannot connect to 10.60 from 10.10 though. – Conor Jan 31 '12 at 5:35
@Coner If you can connect in any meaningful way (TCP? ping?), then traffic is flowing bidirectionally. Are you sure it's not just something like a host firewall on 10.60? – Shane Madden Jan 31 '12 at 5:39
I can telent to port 80 between hosts on the same interface i.e. (on port 5) can connect to port 80 on, but (on port 4) cannot. – Conor Jan 31 '12 at 6:16
what physical port is connected to? Need a clearer idea of your topology to help here. – dunxd Feb 3 '12 at 12:52

These are logically in the same DMZ so the firewall should only see the traffic as layer 2 and not apply any policy to it. You can try the same-security-traffic permit intra-interface command to see if this alleviates the problem but I suspect a misconfiguration on one of your hosts. Make sure the subnet masks on your hosts are all correct and that a host based firewall isn't blocking your requests.

share|improve this answer
I've checked and double checked the configuration of hosts and cannot find any configuration issues. If all hosts are on the same port they are able to communicate. I suspect it has something to do with this. – Conor Feb 1 '12 at 5:23
It shouldn't be NAT since they're both in the same DMZ. Since these hosts are in the same subnet they should not be using any layer 3 functionality of the firewall, just the layer 2 switch built into the 5505. I would try running wireshark or tcpdump on both hosts to try to find out if traffic is even making it. You can also look at your arp tables to make sure you're getting the correct arp entries installed in the table. – resmon6 Feb 1 '12 at 20:23
I've run tcpdump on all hosts and am unable to see any of the traffic arriving at either host. – Conor Feb 7 '12 at 6:39
Take a look at your routing tables route -n and arp tables sudo cat /proc/net/arp on both 10.60 and 10.10. Do you have these hosts directly connected to the ASA or through another switch? You should see arp entries for 10.60 on 10.10 and vice versa. Both hosts should have an entry for 10.1. You should also have a route for on both hosts with a gateway of You'll also want to check iptables on both hosts iptables -nvL – resmon6 Feb 7 '12 at 14:30

Go to ADDM and see if you have the checkbox enabled at the bottom of the Configuration > Interfaces page.

The checkbox says

Enable traffic between two or more hosts connected to the same interface

share|improve this answer

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