Network technologies and trends


June 8, 2017  9:10 AM

Recertifying Cisco expert exams a new twist is here

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
CCIE, Certifications, Cisco

Being a CCIE/CCDE its self is a huge step one would take in his/her life, it’s an informed decision one needs to take as maintaining a CCIE/CCDE  is not an easy task. Every two year one needs to recertify his or her CCIE/CCDE either by passing any CCIE written / CCDE written exam or by passing CCIE/CCDE lab exam. Apart from extensive preparations, one needs to also has to bear the pain of exam costs as Cisco CCIE written exams not quite easy to pass and its cost one a good amount of money.

The recent CCDE practical lab exam cancellation has raised the reputation of expert level exams conducted by Cisco. These days often its been observed people with no experience in networking domain were CCIEs / CCDEs, where as it took over decades of hard earn experience to plan the CCIE journey.

With the announcement of Cisco Continuing Education Program Cisco added a new twist for recertification process of their expert level certifications. Cisco believes that principles like Flexibility, Diversity, and Integrity will be the driving force for this program.

According to Cisco CLN post:

Flexibility is achieved by offering existing Cisco certified individuals an alternative option for recertification, in addition to the already existing option of recertifying by passing the relevant exam(s). Diversity is achieved by allowing individuals a wide range of preapproved items, such as online courses, instructor-led training, authoring of content, and Cisco Live training offerings (collectively called “Continuing Education items”), which can be pursued to earn credits toward recertification. Integrity is achieved by having Cisco authorized content providers, who deliver the content to the individual seeking recertification, validate the credits submitted by that individual.”

The Continuing Education Program is governed by the Cisco Continuing Education Advisory Board. Candidates who choose to recertify through the Continuing Education Program will be required to earn a certain number of credits by completing the required Continuing Education item(s) as delivered by a content provider and paying the Continuing Education administrative fee before their current certification becomes inactive.

Once candidates have earned the designated number of credits and paid their Continued Education administrative fee, they will be recertified as per the existing recertification policies.

The Cisco Continuing Education Program is valid only for the people who are holding a valid Cisco expert level certifications like CCIE and CCDE in either active or suspended status, also those who hold Emeritus status are eligible for this program with few exceptions

  • Candidates in Emeritus status who are required to pass both a written exam and a lab to become active again
  • Candidates who achieved Emeritus status by earning Business Transformation Certifications as described on the CCIE website

In order recertify Cisco Expert level certifications like CCIE and CCDE, one must abide by the following three steps

  • Agree to the Terms and Conditions associated with the Continuing Education Program as part of the enrollment process
  • Earn 100 credits required by completing any of the preapproved Continuing Education offerings
  • Pay the Continuing Education administrative fee

One can enroll by visiting the Continuing Education Program portal using their CCO login details and agree to the terms and conditions. Once logged in the portal shows the active status of their certifications and when they are expiring

continuing-education-program

Cisco had provided multiple options to earn credits, one way of earning credits is to attend Cisco Live training sessions and one can earn maximum of 70 credits from the required 100 credits. The below table gives one a brief idea about how the credits are earned for different sessions.

Cisco Live
Session Type Level Credits per Session
Technical Breakout 1000 Level 1
2000 Level 2
3000 Level 3
4-Hour Technical Seminar 1000 Level 3
2000 Level 4
3000 Level 5
8-Hour Technical Seminar 1000 Level 6
2000 Level 8
3000 Level 10
4-Hour Instructor-Led Lab 1000 Level 3
2000 Level 4
3000 Level 5
8-Hour Instructor-Led Lab 1000 Level 6
2000 Level 8
3000 Level 10

Cisco charges $300 US as administrative fees to recertify ones CCIE and CCDE through continuous education program. Cisco has listed all the rules and criteria at Continuing Education Program portal about this programs its recommend to read the post in details to know what are those criteria, some of the rules governed by Continuing Education Program are as follows

  • For Expert-level certifications, new recertification dates will be issued as per existing Cisco CCIE policies and  procedures; therefore, there may be a time lag between completion of  requirements and issuing of the recertification date.
  • Credits, once earned, will be valid for three years from the date they were earned, as long as they do not meet either of the  criteria described here:
  • Credits will expire if a new recertification cycle starts, either by passing an exam or recertifying some other credential.
  • Credits will expire if your certification becomes inactive before completing the Continuing Education requirements.
  • Credits earned for a given course can only be counted once within the recertification cycle. Repeating the same course will not count towards recertification credits.
  • Credits, once used, cannot be reused for any other certification track or level.
  • Credits must be used (1) before they expire, or (2) during the certification cycle in which they were earned, whichever occurs earlier.
  • Students who are approved to use printed student kits per the exception process can still log into the digital kit using the credentials provided in order to register within the digital kit platform that is linked to the Continuing Education database.

One can view the full catalog of the Continuing Education offerings that have been approved by the Cisco Continuing Education Advisory Board logon to the Continuing Education Program portal. Also one could access the complete program catalog by visiting this link

Well, Cisco has taken some concrete methods to maintain the credibility, integrity, and diversity of their expert level exams. However, the question arises here is it worth to spend this amount of money and time for recertification?

The brighter side of this program is, it offers enormous options to recertify Cisco Expert level exams, personally, I am convinced to adopt the new path as I am free to choose the path/technologies to earn required credits to recertify my CCIE.

May 23, 2017  7:37 PM

How to setup a F5 BIG-IP LTM Virtual lab on VMware Fusion?

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
certification, DHCP, Exam, F5, Fusion, Icon, labs, Mac, Network, subnet, Subnet mask, Topology, VMware, VMware ESX

After passing the F5 201 – TMOS Administration Exam, some of the professional friends were keen to know how to build a F5 practice lab on their personnel machines.

In this post we will walk through how to build a virtual lab for F5 201 – TMOS Administration Exam on macOS Sierra step-by-step.

We will be using following topology to built a F5 Virtual lab so that one can practice for their 201 – TMOS Administration Exam. Before starting please ensure VMware Fusion is installed on macOS Sierra

figure-1-f5-ltm-topology

Fig 1 – F5 BIG-IP LTM Toplogy

We will be using four VMWare networks for this lab, by default “vmnet” is created so we need to create three more VMware networks.

  • vmnet2
  • vmnet3
  • vmnet4

The IP Address mapping and functions of VMware networks will be as follow

figure-2-ip-address-schema

Step 1: Launch VMware fusion and then select preferences

figure-3-vmware-fusion

 

Step 2: Click the Icon Network and click lock icon to make changes

figure-4-network

Step 3 : Select + icon to add a custom network named vmnet 2 and assign the Subnet IP 172.16.1.0 and Subnet Mask 255.255.255.0. This will be the internal network. Also ensure to select the following checkbox

  • Connect the host Mac to this network
  • Provide addresses on this network via DHCP

figure-5-add-custom-network

figure-6-vmnet2

Step 4: Select + icon to add a custom network named vmnet 3 and assign the Subnet IP 172.16.2.0 and Subnet Mask 255.255.255.0. This will be the HA network. Also ensure to select the following checkbox

  • Connect the host Mac to this network
  • Provide addresses on this network via DHCP

figure-7-vmnet3

Step 4: Select + icon to add a custom network named vmnet 4 and assign the Subnet IP 10.1.0.0 and Subnet Mask 255.255.255.0. This will be the management network. Also ensure to select the following checkbox

  • Connect the host Mac to this network
  • Provide addresses on this network via DHCP

figure-8-vmnet4

Step 5:  Log into F5 Website and request a free trail version of BIP-IP virtual edition

figure-9-free-trail-of-big-ip-ve

 

Step 6: Once an email is received from F5 with BIG-IP registration key download the BIG-IP VE System VMware Image, since the F5 201 – TMOS Administration Exam is based on TMOS version of 11.4 we will be downloading a BIG -IP V 11.4 – Virtual Edition for our labs. Download an OVA file for  VMware ESX/i Server v4.1-5.1 as its compatible with VMware fusion.

figure-10-big-ip-ve-image

Step 7-a: Import the BIG-IP VE System VMware Image VMware Fusion >File > Import

figure-11-import-big-ip

 

Step 7 – b: Click Choose File

figure-12-choose-file

Step 7 – c: Navigate to the folder where the BIG-IP VE System VMware Image was downloaded and select BIGIP-11.4.0.2384.0-scsi.ova image file and then click open

Click Continue to import the BIG-IP VE System VMware Image

figure-13-big-ip

Step 7 – d:Name the new virtual machine with the desired name and then click save

figure-14-save-big-ip

Step 7 – e: Accept the license agreements

figure-15-accept-license

Step 8: Once the import is completed, click finish and then click Customize Settings to configure the Network settings, if needed one can customize memory , CPU and Hard disk settings

figure-16-finish

Step 9-a:Customize Network Adapter setting to match the topology you are using.

In our case we will match to our topology

figure-17-network-adaptors

Step 9-b:Map Network Adapter to the vmnet4  network  as this will be assigned to the management interface of BIG-IP Virtual Appliance

figure-18-network-adaptor

Step 9-c:Map Network Adapter 2 to the Bridge Networking Interface (in our case Network Adapter 2 will be bridged to the Wi-Fi  adapter which is connected to the external network 192.168.1.0/24)

figure-19-network-adaptor2

Step 9-d: Map Network Adapter 3 to the vmnet2 network as this will be assigned to the internal interface of BIG-IP Virtual Appliance

figure-19-network-adaptor3

 

Step 9-e:Map Network Adapter 4 to the vmnet3 network as this will be assigned to the HA l interface of BIG-IP Virtual Appliance

figure-19-network-adaptor4

By following above steps one could a build a F5 BIG-IP LTM lab on their laptop using VMware Fusion. In upcoming post we will see how to do an initial configuration on F5 BIG-IP Virtual Edition to run F5 201 – TMOS Administration Exam labs on their laptops.


May 3, 2017  12:55 PM

How to ace F5 – 201 TMOS administration certification exam?

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
application, F5, Virtual lab

In order to be  a F5 Certified BIG-IP Administrator , one must pass two exams

  • Exam 101 – Application Delivery Fundamentals
  • Exam 201 – TMOS Administration

Upon passing Exam 101 Application Delivery Fundaments he/she becomes eligible to take Exam 201 TMOS Administrator provided he /she appears for Exam 201 in two years time. Unless one passes both of these exams one cannot expect any certificate from F5.  Upon passing 201 Exam F5 issues a F5 Certified BIG-IP Administrator which can be downloaded from F5certification portal

f5-certification-graphic

Courtesy: F5

Recently I was successful in passing F5 BIG-IP 201 exam and now I am a F5 Certified BIG-IP Administrator.  When it comes to F5 exams they are quite challenging but at the same time they are straight forward.  By having good hands on experience with BIG-IP Appliance and reading the recommended resources provided by F5 one could ace this exam.

When it comes to preparation of any certification exams the main thing one always look for is the right resource, for F5 BIG-IP 201 exam there are few but quite awesome recourses available. By using them one can certainly ace the exam. There is no single dedicated book one can find for this exam however the resources available in form of study guides, videos courses and practice labs are more than enough for F5 BIG-IP 201 exam preparations.

The first thing one should have a right determination and clear vision to ace this exam as this needs good amount of dedication and time, the main resources one depend for the preparation for this exam are available from F5. F5 offers a study guide 201-TMOS Administration V2 for free which any one can download from their portal.

This study guide is very brief in nature and it covers all the topics of blue print of the F5 BIG-IP 201 exam,  the great thing about this guide it comes with lots of hyperlinks for the various topics covered. One should give a good attention to those hyperlinks and read and practice them.

The second great resource available is from F5 University  the recommended training are

  • Getting Started with F5 products
  • LTM Essentials

These videos are quite helpful in understanding the concepts and F5 terminologies, the video courses are presented in very simple manner and  quite rich in information . The content of these videos and the quiz presented after each module/topic are quite informative and relevant from exam perspective.

Thirdly the F5 Training labs which are free comes with great work books and one can get good hands on experience on F5 BIG-IP Appliances, the labs presented are so good that one can really master how to administrator BIG-IP Appliance LTM module.

Apart from using the F5 training labs , I built a virtual lab on my Mac book using F5 Big IP Virtual Appliance with 90 days trail license.

The great thing about F5 is the free resources provided by them are quite good and more than enough to nail the F5 exams , however one need to give details to minute little details like the TMSH commands usages, events generated by BIG-IP Appliance, the led status etc.


April 6, 2017  11:08 AM

Cisco have issues with certain software versions of ASA and Firepower appliances as it drops traffic after 213 days

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
ASA, Blog, bug, Cisco, console, Firewalls, HTTPS, Reboot, Security, SSH, vulnerabilities

Cisco released a field notice and also published a  blog about the latest bug found in Cisco ASA and certain versions of Firepower appliances, according to Cisco the bug CSCvd 78303 has no vulnerabilities rather it’s a “functional software defect”.

The impact of this bug is so disruptive,  it stops passing network traffic after approximately 213 days 12 hours (~ 5,124 hours) of uptime of a device. Which can have a huge impact on any production network and can bring down services.

The affected device will not receive or respond to ARP packets. Which in turn not only affects the  transient traffic, but also affects the SSH, HTTPS and Telnet traffic, which is mainly used for administration purpose of the device. However console access is not affected.

The affected versions of ASA and Firepower are follows:

ASA version 9.1 releases 9.1(7)8 and higher

ASA version 9.2 releases 9.2(4)15 and higher

ASA version 9.4 releases 9.4(3)5 and higher including 9.4(4)

ASA version 9.5 releases 9.5(3) and higher

ASA version 9.6 releases 9.6(2)1 and higher including 9.6(3)

ASA version 9.7 releases 9.7(1) and higher

FTD version 6.1 releases 6.1.0.1 and higher

FTD version 6.2 releases 6.2.0 and higher

One way to prevent the issue is to reboot the device, however the reboot will not solve the issue permanently and its going to reoccur after  approximately 213 days and 12 hours.

Officially Cisco has is yet to provide a fix. Still its not clear which ASA or FTD version will fix this bug.

However upon opening the TAC case it was recommended the bug has been fixed in the following ASA versions 9.4(4.5), 9.7(1.4) ,9.6(3.1) and 9.5(3.8). One cannot take this as on official answer, however this was recommended to us from Cisco TAC.

One has to keep a close eye on what Cisco is going to recommend for this issue, however the best approach is to open a TAC case with Cisco and seek their opinion.


March 31, 2017  6:43 PM

Palo Alto Networks Next-Generation Firewall wins SANS Best of 2016 Award

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
Automation, Cyberattacks, Palo Alto Networks, platform, SANS, survey, Vendors

SANS institute conducts a survey every year among its community for nominations of the SANS “Best of the Year” awards for  products and services that have successfully provided increases in both the effectiveness and efficiency of cybersecurity programs.  The SANS “Best of  Awards” program was created to raise awareness of the solutions that organisations are using to successfully fend off attacks.

The good thing about these awards are , they are not driven by vendors rather they are driven by the people who are actually using those products/solutions or services.

One of the categories SAN conducts survey among its community is “Next Generation Firewall” category and in this category Palo Alto Networks Next-Generation Firewall wins the award for year 2016. The direction taken by Palo Alto Networks towards their platform made them leaders in Next Generation Firewall category. The flexibility and features offered by Palo Alto Networks on a single platform certainly  makes operational life easier for Security Engineers.  Thus, we believe most of the end-users preferred Palo Alto Networks as their preferred Next Generation Firewall in the survey conducted by SANS.

Some of the key reasons behind this awards are as follows

  • Focus on preventing cyberattacks
  • Delivering Innovative features
  • Automation
  • Protection delivered everywhere.

With this kind of focus one could anticipate that Palo Alto Networks are going to lead from the front in Next Generation Firewalls segment for at least next 3-4 years.

 


March 30, 2017  5:19 AM

Cisco ASA VPN troubleshooting  – Decaps but No encaps

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
ASA, bug, Cisco ASA, Cisco VPN, firewall, NAT, Palo Alto Networks, Policies, Proxy, Troubleshooting, tunnel, VPN

Recently we observed a strange issue while building a site to site VPN tunnel between a Cisco ASA [9.1( 5) ] and Palo Alto Next Generation firewall.(PAN-OS 7.0.9) It was observed always phase 1 part of tunnel established successfully with peer however phase 2 failed to come up.

Always we were seeing issues with encapsulation, the packets sent were never encapsulated, however the packets received from remote peers were de capsulated, this means  the ASA was not encrypting the data. The below logs demonstrates the error,

#pkts encaps: 0, #pkts encrypt: 0, #pkts digest: 0

#pkts decaps: 74, #pkts decrypt: 0, #pkts verify: 0

#pkts compressed: 0, #pkts decompressed: 0

#pkts not compressed: 0, #pkts comp failed: 0, #pkts decomp failed: 0

#pre-frag successes: 0, #pre-frag failures: 0, #fragments created: 0

#PMTUs sent: 0, #PMTUs rcvd: 0, #decapsulated frgs needing reassembly: 0

#TFC rcvd: 0, #TFC sent: 0

#Valid ICMP Errors rcvd: 0, #Invalid ICMP Errors rcvd: 0

#send errors: 0, #recv errors: 74

 

We did a through troubleshooting and we ensured the following ay both ends of the firewalls

  • Ensure both the firewalls have an appropriate route for the interesting traffic / proxy id
  • Ensured the ACL / Policies are matched
  • Ensured NAT configuration is done properly as were using source based NATTing at both the end.
  • Ensured proper debugging is done at both ends,
  • Involved vendors to see what the issue was

Upon through troubleshooting it was discovered the ASA was hitting a bug CSCuo58411

This bug basically creates duplicate entries in tunnel manger and one could see from the below logs

IPSEC(crypto_map_check)-3: Checking crypto map outside_map 10: matched.
Jul 24 08:20:49 [IKE COMMON DEBUG]Duplicate entry already in Tunnel Manager

IPSEC(crypto_map_check)-3: Looking for crypto map matching 5-tuple: Prot=1, saddr=10.0.100.2, sport=45638, daddr=192.168.120.100, dport=45638

IPSEC(crypto_map_check)-3: Checking crypto map outside_map 10: matched.
Jul 24 08:20:50 [IKE COMMON DEBUG]Duplicate entry already in Tunnel Manager

The work around worked for us to fix this issue, was to upgrade the ASA from 9.1(5) to 9.5(3)6 . The other recommended work around to fix this issue is

Issue “debug menu ike-common 10” to remove the stale IKEv2 entries (this will delete all current IKEv2 connections)


March 20, 2017  1:17 PM

How to re-image the Cisco Identity Services Engine (ISE) 2.2 on a Cisco SNS appliance from Cisco Integrated Management Controller?

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
Analytics, application, Cisco, Cisco security, DHCP, end point, End-user, Java, KVM, NAC, Security, Spoofing, threats, vulnerabilities

When it comes to re-imaging the Cisco Identity Services Engine (ISE) 2.2 on a Cisco SNS appliance , one can use the KVM console comes with Cisco Integrated Management Controller. If one wants to re-image the Cisco SNS-3415-K9  appliance  he/she could face huge challenges with the java especially when the appliance is running on Cisco IMC firmware version 2.0(1b).

cimc-firmware

ise-error-1

ise-error-2

The KVM console fails to open with most of the java versions except the Java 7 Update 21 version.

In this post we will see how one can use a KVM console to re-image the Cisco Identity Services Engine (ISE) 2.2 on a Cisco SNS appliance.

Step 1 : Download the Cisco ISE 2.2 image from Cisco web site, make sure to have a valid CCO login id with support contracts.

Step 2: Connect to CIMC and log in using the CIMC credentials

Step 3 : Launch the KVM console

launch-kvm-console

Step 4 : Select Virtual Media and activate the virtual device

mapping-virtual-drive

Step 5 : Select Virtual Media>Map CD/DVD and select the ISE 2.2 ISO image and click Map Device

map-ise-imagemap-ise-image-1

Step 6 : Select Macros >Static Macros > Ctrl-Alt-Del to boot the ISE appliance with ISE 2.2 ISO image

step-6

Step 7 : Select Macros >Static Macros > Alt-F’s > Alt-F6  to enter into the boot menu

step-6

Step 8: At boot prompt, press 1 and Enter from KVM console to install ISE 2.2

step-8

Step 9: Once all the required files are copied type setup to configure the ISE appliance

setup-command

By following above steps one could re-image the Cisco Identity Services Engine (ISE) 2.2 on a Cisco SNS appliance.


March 9, 2017  7:36 AM

What’s new in Cisco Identity Services Engine (ISE) 2.2? – Series 3

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
Analytics, application, Cisco, Cisco security, DHCP, end point, End-user, NAC, Security, Spoofing, threats, vulnerabilities

Cisco Identity Services Engine (ISE) 2.2 does offer lots of new features , in this post we will continue with those features which are focusing on stopping and containing the threats. These new features are quite helpful in reducing risk and contain threats by dynamically controlling network access.

  • Multiple Trustsec Matrices

Cisco Identity Services Engine (ISE) 2.2 offers flexibility to create different set of policies for different locations and scenarios. The Multiple Trustsec Matrices feature can now support up to 5 different policy sets and has an ability to assign different matrices to network devices

The feature addresses two use cases specifically:

  1. In the ISE DEFCON use case, administrators can create predefined policies to address different threat climates, and switch between them in the event that the nature or level of network threats changes. For major attacks, admins can immediately change policies to significantly restrict access

  1. The Separate Administrative Domains use case gives administrators the ability to create and implement policies that are specific to geographical locations, roles and responsibilities for their organization. Different admins can control their own policy sets, enabling greater flexibility.

figure-1-1-defcon-use-case

Source : Cisco Systems

The new enhancements in Multiple Trustsec Matrices  helps an ISE administrators to implement or apply predefined policy set based on threat levels or business location. This helps in

Increase the response time for threats.

Increases efficiency as policy changes can be applied to different operational zone with centralized management.

Offers Segmentation flexibility.

  • Threat-Centric NAC Enhancements

Cisco Identity Services Engine (ISE) 2.2 has expanded its  support for third-party vulnerability and threat data sources on an open platform. Now Cisco Identity Services Engine (ISE) 2.2  can take threat intelligence from Tenable, Rapid 7 and Cisco Cognitive Threat Analytics (CTA). These new capabilities will further enhance the posture assessments as there is an access for much broader range of threat-incident intelligence.

figure-1-2-threat-intelligence

Source : Cisco Systems

This enhancement comes very handy especially when the number of devices connected to networks are increasing day by day and at the same time their exposure to threats is increasing as well.  This can help in not only reducing the remediation time for undetected threats and vulnerabilities as the ISE 2.2 applies multiple vulnerabilities data sources but also an automated CoA is applied based on vulnerability intelligence.

  • Anomalous Behaviour Detection

Cisco Identity Services Engine (ISE) 2.2 can now detect device behaviour consistent with MAC Address spoofing. Now detections are based on

Any change to DHCP Class

Change in access method (Ex: Wired->Wireless

Significant Operating System change

Significant profile change

This enhancement helps in  quick threat  remediation by dynamically updating the policy to prevent or change access.

Cisco Identity Services Engine (ISE) 2.2 will certainly going add value to networks as they are focusing more controlling threats automatically and its worth to invest on this technology especially securing end points at an entry level.


March 4, 2017  7:07 PM

What’s new in Cisco Identity Services Engine (ISE) 2.2? – Series 2

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
802.1x, anti--spyware, Anti-virus, application, Applications, BYOD, Cisco, Cisco security, end point, End-user, P2P, Patch management, Program, Security, visibility, Wireless

Cisco Identity Services Engine (ISE) 2.2 comes with lots of new features, in our previous post we did discussed about

  • Enhanced Visibility
  • Next-level Posture Capabilities

The new enhancements doesn’t stop here, Cisco Identity Services Engine (ISE) 2.2 has much more to offer. Some of the enhancements which we will be highlighting in this post are

  • Easy ISE Setup for Wireless

Yes the Cisco Identity Services Engine (ISE) 2.2  eases the setup for Wireless networks, in past the ISE setup for wireless took great amount of time, as one needs to configure ISE, WLC and portal builder. Often multiple team members were involved to complete the necessary tasks.

Cisco Identity Services Engine (ISE) 2.2  comes with a built-in wizard which captures all of the data required for wireless deployments, which certainly reduces human errors .

Cisco claims with Cisco Identity Services Engine (ISE) 2.2  one could save the great amount of time and one can deploy ISE for wireless in as little as 10 minutes. This seems to be a great enhancement which Cisco has added with ISE 2.2, Cisco Identity Services Engine (ISE) 2.2  comes enabled with three different use cases

  1. 802.1X for wireless
  2. Guest services for wireless
  3. BYOD services for wireless

 

figure-1-1-cisco-ise-wireless-deployment

Source: Cisco Systems

This new enhancement ensures the faster setup of ISE and intuitive process minimises human errors. This certainly makes life easier for an ISE administrator.

  • Improved Posture Visibility

With improved posture visibility,  ISE 2.2 is capable of delivering enhanced application, user and device inventories. ISE 2.2 application libraries have been expanded with wider array of applications such as  P2P apps, patch management apps, anti-spyware, anti-virus, and anti-malware programs, and much more.  This empowers an administrator with greater visibility and more granular control over those applications as they can not only see the potential problems but also they can kill or uninstall the suspicious/ malicious  applications from end user end points.

figure-1-2-ise-posture-vibility

Source: Cisco Systems

Certainly the improved posture visibility offers  extensive visibility, great control and continuous monitoring features to an ISE administrator.


March 3, 2017  9:30 PM

What is an error “Subtype:Encrypt Result:Drop” in Cisco ASA Firewalls?

Yasir Irfan Yasir Irfan Profile: Yasir Irfan
ACL, ASA, Cisco, Cisco ASA, DROP, firewall, Packet Tracer, Routers, Security, VPN, VPN Tunnel

After building a site to site VPN tunnel between Cisco ASA and any other firewall or router, often the tunnel is tested using the packet-tracer command in Cisco ASA firewall.

While running a packet tracer when one sees an error “Subtype:Encrypt Result:Drop” as shown below

Phase: 10

Type: VPN

Subtype: encrypt

Result: DROP

Config:

Additional Information:

 

Result:

input-interface: INSIDE

input-status: up

input-line-status: up

output-interface: OUTSIDE

output-status: up

output-line-status: up

Action: drop

Drop-reason: (acl-drop) Flow is denied by configured rule

The tunnel will never come up. And one might wonder what this error is?

The error was reported while we were trying to initiate the traffic from the source IP 192.168.1.1 to the destination IP 172.16.1.1 on port 80. The IP 192.168.1.1 happens to be the local IP which is natted to 172.17.1.1. In this case source NAT was used so that the actual IP was never disclosed to remote end.

ITKE-FW01# packet-tracer input INSIDE tcp 192.168.1.1 80 172.16.1.1 80

Phase: 1

Type: CAPTURE

Subtype:

Result: ALLOW

Config:

Additional Information:

MAC Access list

 

Phase: 2

Type: ACCESS-LIST

Subtype:

Result: ALLOW

Config:

Implicit Rule

Additional Information:

MAC Access list

 

Phase: 3

Type: UN-NAT

Subtype: static

Result: ALLOW

Config:

nat (INSIDE,OUTSIDE) source static obj-192.168.1.1 obj-172.17.1.1 destination static obj-172.16.1.1 obj-172.16.1.1

Additional Information:

NAT divert to egress interface OUTSIDE

Untranslate 172.16.1.1/80 to 172.16.1.1/80

 

Phase: 4

Type: ROUTE-LOOKUP

Subtype: Resolve Egress Interface

Result: ALLOW

Config:

Additional Information:

found next-hop 192.168.10.1 using egress ifc  INSIDE

 

Phase: 5

Type: ACCESS-LIST

Subtype: log

Result: ALLOW

Config:

access-group INSIDE in interface INSIDE

access-list INSIDE extended permit ip any any

Additional Information:

 

Phase: 6

Type: NAT

Subtype:

Result: ALLOW

Config:

nat (INSIDE,OUTSIDE) source static obj-192.168.1.1 obj-172.17.1.1 destination static obj-172.16.1.1 obj-172.16.1.1

Additional Information:

Static translate 192.168.1.1/80 to 172.17.1.1/80

 

Phase: 7

Type: NAT

Subtype: per-session

Result: ALLOW

Config:

Additional Information:

 

Phase: 8

Type: IP-OPTIONS

Subtype:

Result: ALLOW

Config:

Additional Information:

 

Phase: 9

Type: FOVER

Subtype: standby-update

Result: ALLOW

Config:

Additional Information:

Phase: 10

Type: VPN

Subtype: encrypt

Result: DROP

Config:

Additional Information:

 

Result:

input-interface: INSIDE

input-status: up

input-line-status: up

output-interface: OUTSIDE

output-status: up

output-line-status: up

Action: drop

Drop-reason: (acl-drop) Flow is denied by configured rule

ITKE-FW01#

This error is reported when the interesting traffic ACL is mismatched between the VPN end points, the ACL should be mirrored at both VPN end points. Once the ACL is matched at both the VPN end points one could see the packet-tracer out put changes and it never drops the traffic as shown below.

ITKE-FW01# packet-tracer input INSIDE tcp 192.168.1.1 80 172.16.1.1 80

Phase: 1

Type: CAPTURE

Subtype:

Result: ALLOW

Config:

Additional Information:

MAC Access list

 

Phase: 2

Type: ACCESS-LIST

Subtype:

Result: ALLOW

Config:

Implicit Rule

Additional Information:

MAC Access list

 

Phase: 3

Type: UN-NAT

Subtype: static

Result: ALLOW

Config:

nat (INSIDE,OUTSIDE) source static obj-192.168.1.1 obj-172.17.1.1 destination static obj-172.16.1.1 obj-172.16.1.1

Additional Information:

NAT divert to egress interface OUTSIDE

Untranslate 172.16.1.1/80 to 172.16.1.1/80

 

Phase: 4

Type: ROUTE-LOOKUP

Subtype: Resolve Egress Interface

Result: ALLOW

Config:

Additional Information:

found next-hop 192.168.10.1 using egress ifc  INSIDE

 

Phase: 5

Type: ACCESS-LIST

Subtype: log

Result: ALLOW

Config:

access-group INSIDE in interface INSIDE

access-list INSIDE extended permit ip any any

Additional Information:

 

Phase: 6

Type: NAT

Subtype:

Result: ALLOW

Config:

nat (INSIDE,OUTSIDE) source static obj-192.168.1.1 obj-172.17.1.1 destination static obj-172.16.1.1 obj-172.16.1.1

Additional Information:

Static translate 192.168.1.1/80 to 172.17.1.1/80

 

Phase: 7

Type: NAT

Subtype: per-session

Result: ALLOW

Config:

Additional Information:

 

Phase: 8

Type: IP-OPTIONS

Subtype:

Result: ALLOW

Config:

Additional Information:

 

Phase: 9

Type: FOVER

Subtype: standby-update

Result: ALLOW

Config:

Additional Information:

 

Phase: 10

Type: VPN

Subtype: encrypt

Result: ALLOW

Config:

Additional Information:

 

Phase: 11

Type: NAT

Subtype: rpf-check

Result: ALLOW

Config:

nat (INSIDE,OUTSIDE) source static obj-192.168.1.1 obj-172.17.1.1 destination static obj-172.16.1.1 obj-172.16.1.1

Additional Information:

 

Phase: 12

Type: VPN

Subtype: ipsec-tunnel-flow

Result: ALLOW

Config:

Additional Information:

 

Phase: 13

Type: NAT

Subtype: per-session

Result: ALLOW

Config:

Additional Information:

 

Phase: 14

Type: IP-OPTIONS

Subtype:

Result: ALLOW

Config:

Additional Information:

 

Phase: 15

Type: FLOW-CREATION

Subtype:

Result: ALLOW

Config:

Additional Information:

New flow created with id 4466556, packet dispatched to next module

 

Result:

input-interface: INSIDE

input-status: up

input-line-status: up

output-interface: OUTSIDE

output-status: up

output-line-status: up

Action: allow

ITKE-FW01#

The key thing one need to ensure when an error “Subtype:Encrypt Result:Drop” is reported , they should ensure the interesting traffic ACL is matched at the both ends of VPN end points. By   mirroring the ACL at both the end points we were able to fix the issue.


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