Firepower Threat Defense — DNS Sinkholing
A few days ago I wrote an article that described Firepower DNS Policies. One item that probably warrants a little more discussion is DNS Sinkholing. Although the title of this article indicates Firepower Threat Defense, this will also work with Firepower and Firepower Services.
For this article, I would like to first share some of the challenges around getting security intelligence visibility from DNS requests. A typical enterprise environment will have an internal DNS server. So even though we know we can return “Domain Not Found” with an FTD DNS policy, that might not give us the visibility necessary to remediate a problem.
So if the host in the diagram below makes a DNS request for bad.site.com, what happens? Basically that request is sent to the DNS Resolver. The DNS Resolver will look to the Root Hints and eventually get the request to an Internet based DNS server that has the appropriate domain ownership. The problem with this is that the only request seen by the Firewall (FTD in our example) is the one made by the DNS Resolver. The problem here is that there is no way the Firewall can tell which host needs to be scrubbed by Continue reading
SK Telecom & KPN Deploy Nationwide LoRa IoT Networks
LoRa networks will likely co-exist, not compete, with cellular IoT.
Testing the EIGRP Feasibility Condition (FC)
Last night I was going through some CCIE Routing and Switching VOD’s and found a statement I found interesting. Beyond the fact that I thought the content was far below the expert level (which is fine because a refresher or level-set is typically helpful), I believed it to be incorrect. The statement that was made is as follows:
“A neighbor meets the feasibility condition if the reported distance by the neighbor is the same as or smaller than the feasible distance of the router”
So what are my issues with this statement? First, I thought “feasible distance of the router” is ambiguous and could be assumed to be the advertised distance or the reported distance which is basically the feasible distance of the neighboring router. However, that was not my main problem with the statement. My main concern with this statement is that I have always learned that the feasibility condition is only met if the reported distance (RD) is strictly less than the feasible distance of the local route. So I set out to determine if I had a correct understanding or if the Feasibility Condition (FC) could really be met with a RD equal to the FD.
To test my theory, Continue reading
Telefónica Chooses Cisco’s Network Services Orchestrator
Cisco’s orchestrator uses YANG modeling from Tail-f.
Worth Reading: Little bits of security
The post Worth Reading: Little bits of security appeared first on 'net work.