Block Traffic from a Specific Domain

deklinm
deklinm used Ask the Experts™
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Is there a way I can block all traffic from a specific domain?

Currently i have a Cisco RV042G  Gigabit Dual WAN VPN Router as my gateway.
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Distinguished Expert 2017
Commented:
Please explain, what type of traffic are you looking to block? To which application/service?
The restriction might be on the application/service layer.

You can block access if you know their IP ranges. From discussion https://supportforums.cisco.com/thread/2153386 image of firewall rules
https://supportforums.cisco.com/servlet/JiveServlet/download/3655134-129391/firewall4.PNG

You would add a deny on the wan for those IP ranges.

Depending on service/application, it may have a way to deny access based on domain referenced in the reverse DNS.
AkinsdNetwork Administrator
Commented:
Firewall->Content Filter->Forbidden Domains
use the NetBIOS name (eg instead of blocking www.doamin.com, block domain.com)

https://supportforums.cisco.com/thread/2023056
Some people use a dummy DNS entry for that domain like "127.0.0.1 www.domain.com"
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Distinguished Expert 2017
Commented:
The asker seems to want external resources from a specific doman restricted from accessing their resources rather than preventing local users from accessing an external resource.
AkinsdNetwork Administrator
Commented:
Arnold..... There is a bigger problem if traffic traverses a network without invitation from inside. If you have unsolicited traffic in filtering your network, there is a guarantee that there is a worm on one of the workstations or someone had granted explicit access to the domain unknowingly.

I think the author needs to clarify his request at this point
Distinguished Expert 2017
Commented:
I agree that one could go that the issue is responses coming in from a domain and the asker ones to block it. Your DNS adjustment will prevent access from inside to that domain so no response will be coming back.
The other (my understanding of the question as asked) deals with the asker having an app/service/etc. that needs to be restricted from receiving requests based on a domain name.
Domains do not really generate traffic, but the point is you could restrict on several application based on the domain that is identified by resolving the IP.
Not all IPS resolve to a name, so knowing the range of IPs from which you want access blocked is imperative.
The more rules you add, the worse the performance of your router will become since it has to evaluate everyrule in the order.
you would usually define deny rules before allow ones.

1 deny from_networks_I_do_not_like for any service
allow established (meaning a request from the LAN went out and this matches a response coming back)
2 deny IP1_range to HTTP
3 allow everyoneelse to http

Ordering the rules based on most use is a more efficient use of resources.

Depending on how involved you want to get, you could look at setting up an IPS/IDS using a linux box with two network interfaces with iptables and snort.

It could be in transparent mode where it sits between the router and the LAN.

http://www.fwbuilder.org/ might help you in crafting rules.
http://www.snort.org/

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