Deny TCP outbound connection Polycom and Cisco ASA 5540
Hi,
I am encountering a problem to successfully setup my Polycom HDX 8000 behind Cisco 5540 ASA Firewall.
I am not able to a response the far site after answering the call ( like no video and audio) and the far site keep seeing " Connecting to 1.1.1.1 when I answered the call
I have recorded the logs on ASA saying
Deny TCP outbound connection and Flags AcK on interface outside
I have allow full access from inside and outside for Polycom
Here is the config
Internal IP 10.1.1.247
External IP: 1.1.1.1 ( Fictious IP)
nat (inside) 10 10.1.1.247 255.255.255.255
static (inside,Outside) 1.1.1.1 10.1.1.247 netmask 255.255.255.255
access-list Outside_access_in line 41 extended permit ip 0.0.0.0 0.0.0.0 host 1.1.1.1
access-list inside_access_in line 64 extended permit ip host 10.1.1.247 0.0.0.0 0.0.0.0
Any suggestion ?
I have also tried to open all the ports on ASA but nothing happened.
I didn't understand by that
"You now need to use the REAL IP in the access lost, not the public NAT IP. I would permit IP from any to 10.1.1.247 on the Outside and see if that helps"
Thanks
kevinhsieh
I mean that your access list is wrong, because when the ASA evaluates the access list on the outside interface, it evaluates AFTER NAT, so you need to put the private IP address of your Polycom in the access list, not the public IP address of your Polycom. Cisco says that this is less confusing and leads to fewer mistakes in the access when your devices change IP addresses.
nat (inside) 10 10.1.1.247 255.255.255.255
static (inside,Outside) 1.1.1.1 10.1.1.247 netmask 255.255.255.255
access-list Outside_access_in line 41 extended permit ip 0.0.0.0 0.0.0.0 host 10.1.1.247
access-list inside_access_in line 64 extended permit ip host 10.1.1.247 0.0.0.0 0.0.0.0
Techrunner
ASKER
Hi,
I have tried above access-list, it's not completely not working.
global (Outside) 10 interface
global (inside) 10 interface
nat (inside) 10 HDX8000-Internal 255.255.255.255
static (inside,Outside) 11.22.33.44 HDX8000-Internal netmask 255.255.255.255
That's a bit of a mess. Any particular reason you set this up like that or were you just trying out?
If it's the last I first would try the following:
no global (inside) 10 interface
no nat (inside) 10 HDX8000-Internal 255.255.255.255
nat (inside) 10 10.1.2.0 255.255.255.0
no access-group inside_access_in in interface inside
clear xlate
And see what happens.
The nat (inside) 10 10.1.2.0 255.255.255.0 is added so the rest of your network will also have internet access (not NATted=no access). Of course if you need that (?)
Oh? So there's more than just: access-list inside_access_in remark Polycom HDX8000 Internal to External
access-list inside_access_in extended permit ip host HDX8000-Internal any
?
Ok.
The nat and global command work together. With the nat command you specify what address(es) you NAT from and with global you specify what address(es) to NAT to.
Normally that would be:
global (Outside) 10 interface
nat (inside) 10 HDX8000-Internal 255.255.255.255
Now imagine what happens when you add: global (inside) 10 interface
My gues is that's messing things up.
Techrunner
ASKER
ok I would do that but before I will just inform you that
I have publice remote access server in my inside network and some public webserver in my dmz network.
And the users in my inside network are accessing those servers in the inside network and dmz network using Public IP's Will these change affect anything.
Thanks.
Techrunner
ASKER
Also it very risky for me to apply these change in my live environment.
As far as I can see removing the global shouldn't heave a big impact for that matter. But it looks like you didn't post the entire config (did you), so I can't be 100% sure.
Of course you need to be carefull when making changes in a live environment. I can't assess that risk for you because you know the situation and I don't. Normally it would be best to do that during off hours (if any) so you can rollback without users noticing anything.
Techrunner
ASKER
Hi,
I have applied the alternative way.
I moved the polycom device to the DMZ zone.
Here is the config
global (Outside) 10 interface
nat ( dmz) 10 192.168.4.5 255,255,255,255
static (dmz,Outside) 11.22.33.44 192.168.4.5 netmask 255.255.255.255
access-list Outside_access_in line 29 extended permit ip any host 11.22.33.44
access-list TMG-Proxy_access_in_1 line 3 extended permit ip host 192.168.4.5 any
Now there is no command for
global ( dmz) 10 interface
I have noted a good signal
I tried to make a call it was successful. Polycom see a far site number as public ip.
Perhaps, I tried to make call from another ISP provide internet line. It was unsuccesful. Polycom see far site number as private ip.
Something strange.
Any suggestions ?
Thanks
Ernie Beek
By this: Perhaps, I tried to make call from another ISP provide internet line. It was unsuccesful. Polycom see far site number as private ip.
You mean the situation as it was before?
That could be caused by that global (inside) 10 interface command.
Is it something related with ASA version. Currently I have version 8.2. What if upgrade to 8.3 ???
Ernie Beek
Looks like we're getting lost in translation here.
So you tried to connect from a remote location using ISP1 and it didn't work. Then you tried from another location using another ISP (ISP2) and it did work.
Furthermore, your ASA and polycom are using yet antoher ISP (3)
Am I right so far?
Then it would seem that either:
-the router/firewall configuration at the ISP side is not correct, or
-the ISP might be blocking certain services.
Techrunner
ASKER
Let's make it easy
Location A, B and C
Location A - ( Our DataCenter) ( ISP3)
Location B - ( My home) ( ISP1)
Location C - ( My Freeing Home) (ISP2)
They are located in same city. Location B and Location C have Cisco 857 ADSL routers
Its working fine from Location C and but not from Location B
I know its not correct to say but I am in urgent need help of that.
Thanks