This blog was originally started to better help me understand the technologies in the CCIE R&S blueprint; after completing the R&S track I have decided to transition the blog into a technology blog.
This blog will continue to include questions, troubleshooting scenarios, and references to existing and new technologies but will grow to include a variety of different platforms and technologies. Currently I have created over 185 questions/answers in regards to the CCIE R&S track!! Note: answers are in the comment field or within "Read More" section.
Well it is time to buckle down and make it happen in 2014. The goal is to become a dual CCIE by the end of 2014. I have previously passed the CCIE Sec written in version 3 but I did not have the time to actually sit for the lab and I also wanted to refresh to the latest version of the track. That said I am taking a small step back to refresh and reinforce the theory. The plan is to go through the NP Security track while labbing but also taking the respective NP exam followed by the written and then ultimately sit for the lab.
Here is the order as it stands today:
642-627 IPS - Implementing Cisco Intrusion Prevention System
Let's say you and I are in charge of public transportation for a small city.
Before we send bus drivers out, we need to have a plan.
Control Plane = Learning what we will do
Our planning stage, which includes learning which paths the buses will take, is similar to the control plane in the network. We haven't picked up people yet, nor have we dropped them off, but we do know the paths and stops due to our plan. The control plane is primarily about the learning of routes.
In a routed network, this planning and learning can be done through static routes, where we train the router about remote networks, and how to get there. We also can use dynamic routing protocols, like RIP, OSPF and EIGRP to allow the routers to train each other regarding how to reach remote networks. This is all the control plane.
Data Plane = Actually moving the packets based on what we learned.
Now, after the routers know how to route for remote networks, along comes a customers packet and BAM! this is were the data plane begins. The data plane is the actual movement of the customers data packets over the transit path. (We learned the path to use in the control plane stage earlier).
Below is a list of special use IPv4 address assigned by IANA and should be blocked inbound on external connections. Most security administrators block RFC1918 but do not realize that RFC3330 includes special use addresses that should not be traversing the internet. RFC3330 includes addresses referenced in multiple RFC's including RFC1918.
Address Block Present Use
0.0.0.0/8 "This" Network
10.0.0.0/8 Private-Use Networks
18.104.22.168/8 Public-Data Networks
22.214.171.124/8 Cable Television Networks
126.96.36.199/8 Reserved but subject to allocation
188.8.131.52/16 Reserved but subject to allocation
169.254.0.0/16 Link Local
172.16.0.0/12 Private-Use Networks
184.108.40.206/16 Reserved but subject to allocation
192.0.0.0/24 Reserved but subject to allocation
220.127.116.11/24 6to4 Relay Anycast
192.168.0.0/16 Private-Use Networks
198.18.0.0/15 Network Interconnect Device Benchmark Testing
18.104.22.168/24 Reserved but subject to allocation
240.0.0.0/4 Reserved for Future Use
To block these addresses on an ASA you can leverage network objects. See below:
"access-list outside_inbound deny ip object-group RFC3330 any"
APPLY ACCESS CONTROL LIST TO THE INTERFACE - (Note: you can also be a good internet citizen and block these addresses outbound). In this example we are preventing RFC3330 inbound on the outside interface
"access-group outside_inbound in interface outside"
When building networks leveraging a variety of products you need to consider interoperability and configuration consistency. When leveraging HP A-Series switches in a Cisco environment considerations need to be made in regards to administrative distance (Cisco's term) or route preference (HP's term). In order to ensure that you maintain consistent behavior it is recommended that you modify one or the other and make them consistent with each other. I would recommend following Cisco's administrative preference instead of HP's route preference.
HP's default route preference
Cisco's default administrative distance
Don't get caught with unexpected routing behaviors. Have fun!
I have talked with a few security administrators that seem to struggle with the understanding of FN, TN, FP, TP. I have decided to try to create a simple method to remember.
True/False = This either CORRECTLY or INCORRECTLY identifies an attack
Positive/Negative = This performs and event that takes an ACTION or is ACTION-LESS
True Positive (TP) - A legitimate attack (CORRECTLY) which triggers an IDP to produce and alarm/alert or mitigate the risk (ACTION)
False Positive (FP) - An IDP believes there is an attack taking place (INCORRECTLY) and produces an alarm/alert or mitigates the risk (ACTION).This can cause disrupt legitimate traffic and flood your IDP with alerts drowning real alerts that may be taking place. Some traffic that may cause false positives include:
Legitimate applications that do not follow RFC's
Legitimate traffic in one part of an organization that may not follow normal behaviors in another part of the organization causing alerts.
Signatures that we written poorly and identify both legitimate and illegitimate traffic.
False Negative (FN) - There is an attack that has NOT been identified (INCORRECTLY) and no alarm/alert/mitigation was raised (ACTION-LESS). This causes a false sense of security. This can be caused for a variety of reason which may include:
Signatures miss variations or poorly written
Obfuscation of an attack on the fly
True Negative - (TN) No attack has taken place (CORRECTLY) and no alarm raised (ACTION-LESS).
Confirming that local authentication on the switch and ACS is working after you finished your configuration perform the following:
Run the "test" command on the switch
sw1#test aaa group tacacs+ ro PASSWORD legacy
Attempting authentication test to server-group tacacs+ using tacacs+
User was successfully authenticated.
sw1#test aaa group tacacs+ admin99 PASSWORD legacy
Attempting authentication test to server-group tacacs+ using tacacs+
User authentication request was rejected by server.
Even though the second attempt was rejected it still confirms that ACS rejected the request and is fully operational.
Step 1. Lets have a look at the ACS server. Once logged in navigate to "Monitoring and Reports" and click "Launch Monitoring and Report Viewer"
Step 2. A new window pops up. Navigate to "Reports", "Catalog", and click "AAA Protocols".
Step 3. On the right pain under reports click "TACACS Authentication. As you can see the first 2 entries correlate to what was seen on the switch. A pass and a fail.
Step 4. Lets look at some more details by clicking the magnifying glass under details. Lets look at the authentication that passed. As you can see there is alot of details. The big thing here is the "Status"
Step 5. Lets look at the authentication that was rejected. You can see the reason is identified. Wrong password :/
I will be adding a few more of these types of posts over the next week or so. Quick posts that provide specific detail on a particular topic.
I have just successfully passed the CCIE Security written exam at Cisco Live 2012. The exam was no cake walk and was very challenging. Although I studied all the material from the CCNP security track and read the Network Security Technologies and Solutions (CCIE Professional Development Series) book I did not take any of the CCNP Security exams. I took a little different approach to this CCIE then I took in the R&S track. I will be starting to do the practice labs and will go back to theorythroughout the process to do each of the CCNP Security exams. I am hoping that this ensures that I perform the practice labs without fail and continue to cement the theory throughout the process.
A dynamic, innovative, and skilled individual that is passionate about technology providing technical leadership and architectural oversight. I have in depth knowledge in a variety of technologies which provides a holistic overview of the environment and allows for superior solutions. I take business challenges and create IT solutions that are highly available, scalable, and secure. I have the ability to translate business objectives into IT initiatives. I have a continued thirst for knowledge and share that knowledge with colleagues, business partners, and vendors. I make contributions to the IT community participating in seminars, online forums, and actively blogging.