ASA 5505 blocking single computer

[SugarloafWaterAssociation]

We have had this Cisco ASA 5505 Firewall for about 5 years now and no issues until now. This particular computer is not new however, we recently moved it from a remote site (that is connected to our network) to here at the office. Now this firewall won't let it connect to the internet. I've done the diagnostics and if I remove the ASA 5505 from the equation then it connects and works fine. Plug the ASA 5505 back in and it's blocked. The ASA 5505 is connected to the dsl gateway on one end and on the other end a cisco SG300-20 swtch to which this computer is connected. Everything else on that switch with all the same network settings aside from of course the device ip being different, can connect to the internet like they always have. 

Could the firewall be blocking this computer based on the mac address though I never set that up?

I just don't know what else to try with this computer. I need to access both the devices on our internal network and the internet not either or. I've tried disabling the network card, flush dns, etc with the computer but nothing works unless I remove the ASA 5505

Computer: Lenovo 90AY000AUS

OS: Windows 10 64-bit

MAC: 00-FF-E7-AB-**-**

[parviz]

Hi,

how many endpoints connected to your network and what type license in ASA?

[SugarloafWaterAssociation]

What is your definition of endpoint in this case. Also where do I find Licence information?

[Cristian Matei]

Hi,

  Can you post the output of "show license" and the complete configuration? Do you use the ASA as a DCHP server for your clients? How many current users are having Internet access through the ASA 5505? From the non-working PC, can you at least reach your default gateway which is the ASA?

Regards,

Cristian Matei.

[SugarloafWaterAssociation]

 "" Can you post the output of "show license" and the complete configuration? ""

How do I do this?

 "" Do you use the ASA as a DCHP server for your clients? ""

No, everything is static

"" How many current users are having Internet access through the ASA 5505? ""

About 10 devices

"" From the non-working PC, can you at least reach your default gateway which is the ASA? ""

No, I keep getting the error DCHP server is unplugged when I run the windows troubleshooter.

[Cristian Matei]

Hi,

   You're saying that everything is static but at the same time you expect the PC to get an IP address from DHCP? If you don't run DHCP, configure the new PC with a unique IP address from the same subnet as the others, with the same default gateway and DNS servers. Let's see if it works.

Regards,

Cristian Matei.

[SugarloafWaterAssociation]

Remember that the ASA is connected to a switch. I enter all the network setting manually. We have our own network and all the ip's are static. We insert DNS server addresses into each device.

[Cristian Matei]

Hi,

  If you have a static IP configured from he same subnets s the other PC's and the ASA, you should at least be able to reach your default gateway, the ASA. And if your PC has static IP assigned, how come you get the below message which looks to say otherwise:

"No, I keep getting the error DCHP server is unplugged when I run the windows troubleshooter."

Regards,

Cristian Matei.

[SugarloafWaterAssociation]

---

@Cristian Matei wrote:

Hi,

  If you have a static IP configured from he same subnets s the other PC's and the ASA, you should at least be able to reach your default gateway, the ASA. And if your PC has static IP assigned, how come you get the below message which looks to say otherwise:

"No, I keep getting the error DCHP server is unplugged when I run the windows troubleshooter."

Regards,

Cristian Matei.

---

Sorry I meant to put DNS server not DCHP. 

Also like I said before, I can reach everything on our network through the switch but if I try to use the internet I have to go through the ASA 5505 and it is unresponsive. 

just a small network map so you can understand how it's configured.

Internet-----DSL Gateway (With Wifi)-----ASA 5505-----SG300-20-----our network (including my computer)

[SugarloafWaterAssociation · Accepted solution]

So I disconnected the network from the ASA 5505, power cycled everything and then used the link below to reset my network settings and now I'm connected. I don't know what went wrong or where but the point is I'm up and running again. Thank everyone for their help.

https://www.lifewire.com/how-to-reset-network-settings-in-windows-10-4684679