02-06-2012 09:05 AM - edited 03-11-2019 03:24 PM
I have a situation where we have a single DMZ server currently statically forwarded to a single public IP. TCP ports 80, 443, 8080, 8500, 53, and 21 are open to this server via an access list.
However, we have added an additional server to the DMZ, and because our web developers did not communicate with me beforehand, we are forced to use the same DNS name (thus, the same piblic IP) for this server. This server only needs traffic on TCP/8800 forwarded to it.
I am using ASDM 6.4 for configuration of this, as I am required to take multiple screen shots of the procedure for our change control policy.
My question lies in the reconfiguration of NAT/ PAT. Since our current server has a single static NAT to a single public IP, it is simply natted for "any" port. I understand that I can add the new server as an object, and only PAT it on TCP 8800, but will I then have to go back and reconfigure the first server multiple times for PAT, or will the ASA notice the specific PAT, and forward 8800 to the new server without affecting the existing "old" server?
It appears ASDM will not allow me to put multiple ports into a single network object. I am assuming I will need to add 6 separate object translations for the "old" server based on TCP port, and 1 object translation for the "new" server, correct?
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02-06-2012 10:07 AM
Hello Michael.
It appears ASDM will not allow me to put multiple ports into a single network object. I am assuming I will need to add 6 separate object translations for the "old" server based on TCP port, and 1 object translation for the "new" server, correct?
That is correct, for the NAT configuration you need to do it like that, This setup is going to work as you expect so you will not face any issues.
Regards,
Julio
Do rate all the helpful posts!!
02-06-2012 10:07 AM
Hello Michael.
It appears ASDM will not allow me to put multiple ports into a single network object. I am assuming I will need to add 6 separate object translations for the "old" server based on TCP port, and 1 object translation for the "new" server, correct?
That is correct, for the NAT configuration you need to do it like that, This setup is going to work as you expect so you will not face any issues.
Regards,
Julio
Do rate all the helpful posts!!
02-07-2012 01:56 PM
JCarvaja, thank you for your help. That worked as expected.
However, I am having a slightly different issue on the outbound side. I need the "old " server to statically resolve OUTBOUND on port 5080 as the correct public IP, and it appears the ASA is not translating this properly. I have removed all standard static NATs for the two servers in our DMZ, and I am doing only PAT. Inbound, all of the correct ports respond. Outbound, the "old" server is resolving as the public outside interface of the ASA, whereas when the server sends outbound, on port 5080, I need it to resolve as the same IP it uses for inbound.
I think I may just be missing a setting somewhere. It also appears that I can statically NAT the entire DMZ network to use the correct public IP, rather than the interface address, but my question then lies on the inbound side. If the two servers send out using the same public IP, based on the DMZ network, when a request comes in, will the ASA defer to using PAT, because it doesn't know a specific host to translate to? If thats the case, it sounds like the most logical option.
02-07-2012 02:54 PM
Hello Michael,
Glad I could help!
I am not following you, what do you mean by I need the "old " server to statically resolve OUTBOUND on port 5080 as the correct public IP, and it appears the ASA is not translating this properly.
Also you said you do not have any static one to one translation and only have inbound PAT, can you share the inbound pat configuration??
Please explain me this in order to help,
Diagrams always help
Regards,
Julio
02-08-2012 05:51 AM
OK, so I beleive I've truncated this down to what you need in order to give me a hand. Remember that I must configure this using ADSM for screenshot purposes. There is currently a temporary static one-to-one NAT in place for NCAFTP01 until we resolve the outbound issue, but I realize this must be removed to properly test. I'll explain the desired topology below the config.:
: Saved
:
ASA Version 8.3(1)
!
hostname ASA-SVRRM-5510
domain-name domain.corp
!
names
name 10.20.1.23 NCASK333
name 10.20.1.40 Barracuda
!
interface Ethernet0/0
nameif Outside
security-level 0
ip address 1.1.1.3 255.255.255.248
!
interface Ethernet0/1
description DMZ
nameif DMZ
security-level 20
ip address 172.16.10.1 255.255.255.0
!
interface Ethernet0/2
shutdown
no nameif
no security-level
no ip address
!
interface Ethernet0/3
nameif Inside
security-level 100
ip address 10.20.1.249 255.255.0.0
!
!
object network mail.domain.com
host 10.20.1.40
object network NCASK333
host 10.20.1.23
object network obj-10.20.1.218
host 10.20.1.218
object network obj_any
subnet 0.0.0.0 0.0.0.0
object network NETWORK_OBJ_10.192.0.0_16
subnet 10.192.0.0 255.255.0.0
object network NETWORK_OBJ_10.20.0.0_16
subnet 10.20.0.0 255.255.0.0
object network Remote Site
host 10.1.1.1
object network NCAFTP01:80
host 172.16.10.10
object network 1.1.1.5
host 1.1.1.5
object network NCASK820
host 10.20.1.61
description Exchange Server/ KMS
object service AS2
service tcp source eq 8800 destination eq 8800
object network NCAFTP01:21
host 172.16.10.10
object network NCAFTP01:443
host 172.16.10.10
object network NCAFTP01:53
host 172.16.10.10
object network NCAFTP01:53UDP
host 172.16.10.10
object network NCAFTP01:8080
host 172.16.10.10
object network NCAFTP01:8500
host 172.16.10.10
object network NCAFTP01:5080
host 172.16.10.10
object network NCADMZ02:8800
host 172.16.10.11
object network NCAFTP01
host 172.16.10.10
object-group service DM_INLINE_SERVICE_1
service-object gre
service-object tcp destination eq pptp
object-group service DM_INLINE_TCP_1 tcp
port-object eq www
port-object eq https
port-object eq imap4
port-object eq pop3
port-object eq smtp
port-object eq domain
object-group service DM_INLINE_SERVICE_2
service-object icmp
service-object icmp traceroute
object-group service DM_INLINE_SERVICE_3
service-object tcp destination eq 8080
service-object tcp destination eq 8500
service-object tcp destination eq domain
service-object tcp destination eq ftp
service-object tcp destination eq www
service-object tcp destination eq https
service-object udp destination eq domain
service-object icmp
service-object tcp destination eq 5080
service-object object AS2
object-group service DM_INLINE_TCP_2 tcp
port-object eq www
port-object eq https
object-group service DM_INLINE_TCP_3 tcp
port-object eq 8080
port-object eq www
port-object eq https
port-object eq echo
object-group network DM_INLINE_NETWORK_5
network-object 172.16.10.0 255.255.255.0
!
nat (Inside,any) source static any any destination static obj-10.192.0.0 obj-10.192.0.0
nat (Inside,ATTOutside) source static NETWORK_OBJ_10.20.0.0_16 NETWORK_OBJ_10.20.0.0_16 destination static NETWORK_OBJ_10.192.0.0_16 NETWORK_OBJ_10.192.0.0_16
nat (Inside,ATTOutside) source static DM_INLINE_NETWORK_1 DM_INLINE_NETWORK_1 destination static NETWORK_OBJ_10.192.0.0_16 NETWORK_OBJ_10.192.0.0_16
!
object network mail.domain.com
nat (Inside,ATTOutside) static 1.1.1.4
object network NCASK333
nat (Inside,ATTOutside) static 1.1.1.6
object network obj-10.20.1.218
nat (Inside,ATTOutside) static 1.1.1.2
object network obj_any
nat (Inside,ATTOutside) dynamic interface
object network NCAFTP01:80
nat (any,ATTOutside) static 1.1.1.5 service tcp www www
object network NCAFTP01:21
nat (any,ATTOutside) static 1.1.1.5 service tcp ftp ftp
object network NCAFTP01:443
nat (any,ATTOutside) static 1.1.1.5 service tcp https https
object network NCAFTP01:53
nat (any,ATTOutside) static 1.1.1.5 service tcp domain domain
object network NCAFTP01:53UDP
nat (any,ATTOutside) static 1.1.1.5 service udp domain domain
object network NCAFTP01:8080
nat (any,ATTOutside) static 1.1.1.5 service tcp 8080 8080
object network NCAFTP01:8500
nat (any,ATTOutside) static 1.1.1.5 service tcp 8500 8500
object network NCAFTP01:5080
nat (any,ATTOutside) static 1.1.1.5 service tcp 5080 5080
object network NCADMZ02:8800
nat (any,ATTOutside) static 1.1.1.5 service tcp 8800 8800
object network NCAFTP01
nat (any,ATTOutside) static 1.1.1.5
!
nat (DMZ,ATTOutside) after-auto source dynamic obj_any interface
!
timeout xlate 3:00:00
!
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 pptp
class class-default
: end
Coming from the outside to public IP 1.1.1.5, we want ports 80, 443, 8080, 8500, 21, and 53 to translate to NCAFTP01/ 172.16.10.10. We want traffic sent to 1.1.1.5 on "AS2" (tcp port 8800) to translate to NCADMZ02/172.16.10.11.
This part is functional, as you instructed above, I simply needed to create individual PAT statements.
My current issue lies in the outbound translation. When we send a request out from NCAFTP01/ 172.16.10.10 on any port, we want it to translate to a public IP of 1.1.1.5. When we send a request out from NCADMZ02/172.16.10.11, we also want it to translate to 1.1.1.5. So in effect, we want it to NAT both devices outbound to the same public IP, but use PAT inbound. These are the only two devices in our DMZ, so if I can simply translate all traffic from the DMZ network outbound to 1.1.1.5, I feel it would be the simplest solution. My question is if we do this, when a request comes inbound from the outside, would the translation fall over to PAT?
This comes about because the client on the outside requires us to use a specific IP to connect to thier EDI server on port 5080.
02-09-2012 08:19 AM
jcarvaja or anyone else,
Have you had the chance to look over the above config? I am sure I am missing something simple, but I am drawing a blank.
Thanks
02-09-2012 10:04 AM
Hello Michael,
I am sorry for the delay!
If an inbound connections comes to the server on port 80, the server will answer on that port as well due to the RPF check on the stateful firewall, so do not worry for that.
Regards,
Julio
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