Securing Your Connection Anywhere You Go

We all know that there are a lot of incomplete security models. Firesheep made this fact painfully obvious to those who regularly work from public hotspots. Although this issue extends beyond insecure wireless deployments, unencrypted hotspots are an easy target. When network traffic isn’t secured in the application layers AND that same traffic is not secured in the network or datalink layers, bad things can and do happen.

TLDR–This article solves this problem by utilizing a Meraki MX60 and the VPN client Native on OSX. To skip to the good stuff, click here.

One approach that some people decide to employ is utilizing a VPN connection for their Internet traffic when connected to untrusted networks. For years, enterprises have utilized these controls to allow secure access to corporate resources. A common trend to day includes utilizing “the cloud” for sensitive enterprise and personal data. While these systems *should* be appropriate resilient, we know that is not always the case. In addition to that, federated authentication schemes and password reuse can also pose additional risk to broken systems and less security conscious users.

Having easy access to some gear, I have been using a Meraki MX60 for a few months. This device makes the configuration simple for several reasons.

  1. Being a cloud managed platform, public IP changes are always tracked and available
  2. DNS “A” records have a configurable hostname and are maintained by the cloud management platform
  3. Standard Protocols are used and work natively with a wide variety of operating systems

Meraki Configuration

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Validation Testing Matters

A couple of weeks ago, a CLN Member Posted a question with the heading Does ASA drop active session.

The specific question was as follows–

I have a time based ACL configured on a Cisco ASA. I need to know if the active sessions are dropped by the ASA when the time limit is over.

For example, users are allowed to connect between 12 and 1 PM. If there are any active connections just before 1 PM then will they be dropped at 1 PM?

Many network and security administrators would blindly assume that a time-based ACL would block or allow traffic based on the time-range attached to the individual ACE. Having quite a lot of experience with the ASA, I was skeptical and assumed that any ongoing connections would continue to allow the flow of traffic. I decided to do a little testing and here is what I found. Continue reading

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Risky Business #349 <– Wow, a LOT Happened in 2014

There’s nothing like taking a 12 hour road trip to help get caught up on podcasts. Even though I have a few more to go, I am feeling pretty accomplished with my progress.

One podcast episode jumped out at me as particularly interesting. This was the Risky Business 2014 [year] in review episode. This episode has the most interesting excerpts and commentary for breaches throughout this year. Have a listen by following the link below.

Risky Business #349 — 2014 in review | Risky Business

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Don’t Let Wireshark’s Assumptions Mislead Your Troubleshooting

In an effort to educate myself on the inner workings of WebEx, I recently looked at a session with Wireshark. Knowing that WebEx audio has the ability to use UDP or TCP, I wanted to isolate the protocol being employed in my configuration. I watched for a new stream of traffic as I enabled the audio portion of a meeting. I found that the audio was using UDP port 9000.

I next applied a filter to see only this traffic. What immediately jumped out at me was what appeared to be malformed and fragmented packets. I also noticed a lot of strange IP addresses like 1.0.0.0, 1.0.0.1, 0.0.0.30, 0.0.0.31 and so on.

WebExUDP9000Knowing that the audio was working perfectly, I could have easily concluded that my eyes were deceiving me. When I looked closer, I quickly realized that Wireshark was recognizing and decoding this as if the packets were Lawful Intercept. Continue reading

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Merry Christmas to the PacketU Community

I wanted to take a moment to wish all PacketU readers a Merry Christmas and a Happy New Year. With that, I leave you with a short video clip of my son playing Silent Night at a church program last week. Longtime friends know that we had a pretty serious health scare with him 5 years ago and we consider ourselves very blessed to have him in our life.

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My Podcasts

Since taking a new role at Cisco, my drive time is less consistent. As a result, finding opportunities to listen to podcasts is more of a challenge. Earlier this week, a road trip I took provided some time to start getting caught up on my listening. Using iCatcher allows me to easily tweet what I’m listening too. As a result of sharing what I listened to, I received some requests regarding the podcasts I listen to. I wanted to share this ever changing list with the PacketU community.

Technology Podcasts

  • Cisco Champion Radio
  • Cisco TAC Security Podcast Series
  • No Strings Attached Show
  • Packet Pushers Podcast
  • Risky Business
  • Software Gone Wild by ipSpace.net
  • The Class-C Block
  • The IPv6 Show
  • The Southern Fried Security Podcast
  • VUPaaS – Virtualization as a Service

Business and Leadership

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Forming a Thought Process for Troubleshooting

Periodically, I get a message from someone asking for troubleshooting help. The most recent of these went something like the following (paraphrasing)–

I have the following routers, R1 through R5, and I cannot ping R5 from R1. Please tell me what the problem is.

In these cases, I could review the configuration or import them into my lab. Inevitably, that might solve the problem for the individual. However, it doesn’t really help the individual solve problems in the future. I prefer to try to help others think through the problem and reach the solution on their own.

R1throughR5

 

Given the symptom of R1 not being able to ping R5, what could that mean? My initial thoughts are– Continue reading

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Positioning an IT Conversation

About a  week ago, I took my wife’s van to the shop. The main issue was it was making a popping noise in the front end. I only observed the noise when steering sharply and the vehicle was in motion. Typically this occurred when parking. Although I was nearly certain this was an issue with a CV joint, I only told the mechanic about the symptoms we had observed.

The reason I didn’t lead the conversation to the CV joint is that I wanted the mechanic to look at the problem objectively. I knew he was the expert and I wanted him to solve the problem instead of replacing a part. In order to shift the responsibility, I needed the mechanic to diagnose the problem and create a plan of action.

Positioning IT Conversations to Solve Problems

At this point in my career, I have worked in various areas of technology. Over the years, I’ve had customers that tell me exactly what they think they need. In some cases, they’re correct. However, there are times that their solution does not fully solve the problem they are observing. On the other hand, some customers take a smarter approach and explain the problem they are trying to solve. Continue reading

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Google and Cloudflare: Encrypting the WWW

A couple of months ago, Google announced that it had started using SSL as a factor in SEO ranking. Since the search giant is the referrer for most website traffic, this is the type of announcement that gets the attention of website owners.

Cloudflare, a popular and easy to implement Content Delivery Network, seems to be stepping up to this challenge. Even their free offering has an option to provide forward facing SSL services. As discussed on Packet Pushsers Priority Queue show 34, they are also modifying SSL in ways that allow them to provide services to organizations without the need to obtain the site owner’s private keys. The likely result of the offering is that many existing and many new Cloudflare customers will take advantage of their SSL services. Continue reading

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Vulnerable OMA-DM Implementations and Over the Air Hacks

Earlier today, I was listening to Risky Business show #341. In this show Matt Solnik discussed vulnerabilities that he attempted to share at BlackHat. I say attempted, because it sounds like they may have had some issues with audio/video during critical times of the presentation. Nonetheless, it seems like there are many vulnerable implementations of the open mobile administration device management (OMA-DM). I took a minute to dig up some of the videos published by Accuvant that makes this stuff real.

Over the Air Code Execution and Jailbreak

NIA-Based Lock Screen Bypass

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Using Ping Sweep to Find MTU Ceiling

Earlier this week I had breakfast with a very interesting group. One of those present had an extensive history with Cisco systems. We talked about his tenure and several of the projects that he had been involved in. For some reason, one that caught my attention was the sweep option that we find in the extended Ping utility. Although it is hard to believe, there was a point in time that this gem didn’t exist.

I’ve written a few articles about the challenges of path MTU discovery and the issues that arise when it misbehaves. Today’s article looks specifically at using a ping sweep and how it can be used to quickly identifying the path MTU ceiling. The topology used for testing is simple and shown below. Notice that the two top routers are connected by a link with a lowered MTU (1492).

Ping Sweep MTU Discovery

Let’s step through the process that an administrator might go through when a networked application isn’t working correctly. He or she would likely determine the endpoints and confirm reachability. For this example, I am testing a connection between 192.168.1.1 and 192.168.4.4. The ping command is the tool of choice for confirming reachability. Continue reading

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Classic IOS as a DNS Server

There is an occasional need for a DNS server in the absence of a dedicated host. This may occur in the following situations–

  • Using PAT, Public DNS may return a non-RFC1918 address for internal server
  • Lab/Demo Environment
  • Other Name Resolution challenges in SOHO, SMB or Branch Office

When these corner-case challenges present, an IOS router may be beneficial by providing basic DNS functions. Assuming the router already has Internet connectivity, the configuration is straightforward–

//enable the dns server functionality
IOS-DNS(config)#ip dns server 

//if public requests should be resolved, configure one or more name
//servers as resolvers and confirm domain-lookups are enabled
IOS-DNS(config)#ip name-server 8.8.8.8 8.8.4.4
IOS-DNS(config)#ip domain-lookup

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