The Journey Starts 2014 - CCIE Security - Blog Post1

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 
• 642-618 FIREWALL - Deploying Cisco ASA Firewall Solutions 
• 642-648 VPN - Deploying Cisco ASA VPN Solutions 
• 642-637 SECURE - Securing Networks with Cisco Routers and Switches
• ISE and WSA 
• CCIE Written 
• CCIE Lab

The primary partner that I am leveraging is CiscoPress and Cisco Docs for the theory and iPexpert for all the heavy labbing. 

The great thing about this journey is that I already eat, sleep, and breath Cisco .:|:.:|:.

Twitter: FE80CC1E

IDP - FN, TN, TP, FP

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 -zero day
• Overloaded IDP 

True Negative - (TN) No attack has taken place (CORRECTLY) and no alarm raised (ACTION-LESS).

Testing AAA Authentication with ACS - Part 1

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.

VPN-IPSEC

Its been a while but I am going to try to post weekly.

Here is a sample configuration for IPSEC VPN between in 2 routers.
Note: 172.16.1.X/32 are loopback interfaces.








R1
Define IKE Phase 1 Policy (ISAKMP)
(config)#crytpo isakmp policy 10
(config-isakmp)#encryption aes 256
(config-isakmp)#authentication pre-share
(config-isakmp)#hash sha
(config-isakmp)#group 2

Define pre-shared key
(config)#crypto isakmp key 0 $pass@word$ address 192.168.1.2

Define IKE Phase 2 Policy (IPSEC)
(config)#crypto ipsec transform-set TRANS-R1-R2 esp-aes 256 esp-sha-hmac

Create ACL to match interesting traffic
(config)#access-list 150 permit ip 172.16.1.1 0.0.0.0 172.16.1.2 0.0.0.0

Create Crypto Map
(config)#crypto map VPN-MAP-R1-R2 10 ipsec-isakmp
(config-crypto-map)#set peer 192.168.1.2
(config-crypto-map)#set transform-set TRANS-R1-R2
(config-crypto-map)#match address 150

Apply Cypto Map to Interface
(config)#interface fas0
(config-if)#crypto map VPN-MAP-R1-R2

Create a route
(config)#ip route 172.16.1.2 255.255.255.255 fas0

R2
Define IKE Phase 1 Policy (ISAKMP)
(config)#crytpo isakmp policy 10
(config-isakmp)#encryption aes 256
(config-isakmp)#authentication pre-share
(config-isakmp)#hash sha
(config-isakmp)#group 2

Define pre-shared key
(config)#crypto isakmp kep 0 $pass@word$ address 192.168.1.1

Define IKE Phase 2 Policy (IPSEC)
(config)#crypto ipsec transform-set TRANS-R1-R2 esp-aes 256 esp-sha-hmac

Create ACL to match interesting traffic
(config)#access-list 150 permit 172.16.1.2 0.0.0.0 172.16.1.1 0.0.0.0

Create Crypto Map
(config)#crypto map VPN-MAP-R1-R2 10 ipsec-isakmp
(config-crypto-map)#set peer 192.168.1.1
(config-crypto-map)#set transform-set TRANS-R1-R2
(config-crypto-map)#match address 150

Apply Cypto Map to Interface
(config)#interface 0/1
(config-if)#crypto map VPN-MAP-R1-R2

Create a route
(config)#ip route 172.16.1.1 255.255.255.255 fas0


Sample Output from R2 - (After ping from R1 source lo0)

R2(config)#do show cry isa sa
IPv4 Crypto ISAKMP SA
dst             src             state          conn-id slot status
192.168.1.2     192.168.1.1     QM_IDLE           1001    0 ACTIVE

IPv6 Crypto ISAKMP SA

R2(config)#do show cry ipsec sa

interface: FastEthernet0
    Crypto map tag: VPN-MAP-R1-R2, local addr 192.168.1.2

   protected vrf: (none)
   local  ident (addr/mask/prot/port): (172.16.1.2/255.255.255.255/0/0)
   remote ident (addr/mask/prot/port): (172.16.1.1/255.255.255.255/0/0)
   current_peer 192.168.1.1 port 500
     PERMIT, flags={origin_is_acl,}
    #pkts encaps: 24, #pkts encrypt: 24, #pkts digest: 24
    #pkts decaps: 47, #pkts decrypt: 47, #pkts verify: 47
    #pkts compressed: 0, #pkts decompressed: 0
    #pkts not compressed: 0, #pkts compr. failed: 0
    #pkts not decompressed: 0, #pkts decompress failed: 0
    #send errors 0, #recv errors 0

     local crypto endpt.: 192.168.1.2, remote crypto endpt.: 192.168.1.1
     path mtu 1500, ip mtu 1500, ip mtu idb FastEthernet0
     current outbound spi: 0x6F76C310(1870054160)

     inbound esp sas:
      spi: 0x1F2B01DC(522912220)
        transform: esp-256-aes esp-sha-hmac ,
        in use settings ={Tunnel, }
        conn id: 1, flow_id: 1, crypto map: VPN-MAP-R1-R2
        sa timing: remaining key lifetime (k/sec): (4605243/2016)
        IV size: 16 bytes
        replay detection support: Y
        Status: ACTIVE

     inbound ah sas:

     inbound pcp sas:

     outbound esp sas:
      spi: 0x6F76C310(1870054160)
        transform: esp-256-aes esp-sha-hmac ,
        in use settings ={Tunnel, }
        conn id: 2, flow_id: 2, crypto map: VPN-MAP-R1-R2
        sa timing: remaining key lifetime (k/sec): (4605245/2011)
        IV size: 16 bytes
        replay detection support: Y
        Status: ACTIVE

     outbound ah sas:

     outbound pcp sas:

Wireshark capture - Anything sourced from R1 L0 is encrypted (ESP) when not sourcing from R1 L0 the packets are sent in clear text.

CCIE Security

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 theory throughout 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.


Thoughts?

Zone-Based Firewall-Part 1 of 2-Basic Configuration

Great 60 minute video on zone-based firewalls by Solarwinds. Instructor Anthony Sequeira walks us through a couple of constructs and demonstrates the configuration.

ASA Packet Flow - Outside Interface to Inside Host

ASA Packet Flow - Inside Interface to Outside Host

EAP Functionality and Requirements

Stream Ciphers Examples

Here is a list of some of the more common Stream Ciphers

SEAL (Software Encryption Algorithm)
RC4
DES and 3DES leveraging OFB (Output Feedback) or CFB (Cipher Feedback)

Block Ciphers Examples

Here is a list of some of the more common Block Ciphers

Blowfish
RSA
DES and 3DES leveraging ECB (Electronic Code Block) or CBC (Cipher Block Chaining)
AES
IDEA
Skipjack
SAFER (Secure and Fast Encryption Routine)

Symmetric and Asymmetric Algorithms - Basic Differences

Symmetric uses only one key for both encryption and decryption. Sender and receiver share the same shared secret to transfer data securely. Algorithms include DES, 3DES, AES, IDEA, RC2/4/5/6, and Blowfish. Also referred to as "secret key" encryption.

DES - 56bit keys
3DES - 112bit and 168bit keys
AES - 128bit, 192bit, and 256bit keys
IDEA (International Data Encryption Alogrithm) - 128bit keys
RC2 - 40bit and 64bit keys
RC4 - 1bit to 256bit keys
RC5 - 0bit to 2040bit keys
RC6 - 128bit, 192bit, and 256bit keys
Blowfish - 32bit to 448bit keys


Asymmetric uses one key for encryption and another key for decryption referred to as public key infrastructure encryption. Key lengths generally ranging from 512 to 4096bits.

Example of asymmetric encryption RSA,EIGamal, Eliptical Curves, and Diffie Hellman

Layer 2 Security Best Practices

Here are a couple of recommendations from Cisco when it comes to securing layer 2

• STP - Leverage Root Guard and BPDU Guard
• Shutdown unused ports
• Leverage DHCP snooping and DAI (Dynamic Arp Inspection)
• Disable unneeded services
• Use port security to restrict the number of MAC addresses that a port can learn
• Limit management access to a layer 2 switch
• Use SNMPv3
• Do not use the native VLAN to send user data. Create a native VLAN and do not add any ports to it.

This was not mentioned but I would also add PVLAN (Private VLANs) and VACL's where appropriate.