Investigating MTU/MSS Issues

I have seen an increase in problems that go back to IP MTU or TCP MSS issues. Its very important to figure out which one you are dealing with so you can troubleshoot it properly.

Both TCP MSS and IP MTU refer to the amount of payload that layer can carry.

A general rule of thumb is that IP MTU is a layer 3 concept, therefore any layer 3 device would affect the MTU like a router. TCP MSS is a layer 4 concept and is affected by NAT, proxies, etc..

When using Wireshark, you will see ICMP error messages stating “Destination Unreachable (Fragmentation needed)”. Within the ICMP packet you will see the “MTU of next hop” that is allowed. MTU issues are tricky to troubleshoot since the symptoms range from timeouts, drops or poor performance. Also pay attention to your network firewalls and ensure that ICMP error packets are allowed back to the client.

When it comes to TCP MSS, you will see the MSS values in the TCP SYN packets. Super small TCP MSS values such as anything less than 500 bytes will cause performance-related issues.

Build It and They Will Come (Paul W. Smith)

 

If you follow the sport of baseball then you’ve probably heard of Shoeless Joe Jackson. A century’s worth of World Series ago, Shoeless Joe played in his very last game. His White Sox ended their season on October 9, 1919, with a Game 8 loss (they played best of 9 in those days) to the Cincinnati Reds by a score of 10-5. Shoeless Joe went 2-for-5 (a double and a home-run).

What Is Branding and Why Is It So Important for Your Company? (John Gumas)

So, what’s this thing called “branding” that everyone talks about? Branding is one of those terms that if you ask ten different marketing experts to define it, you’ll get ten different answers. The one consistent point you will hear is how important a coordinated branding program is to your company’s success.

It’s all about your customers’ perception

What Is Cloud Security Posture Management (CSPM)? by Gilad David Maayan

 

Cloud Security Posture Management (CSPM) solutions enable organizations to automate cloud security processes. Organizations use CSPM tools to set up cloud-native security policies that maintain scalability while ensuring compliance needs are met. This is achieved by aligning compliance regulations with cloud standards, prioritizing risks, and automating processes accordingly.

LAB: What happens when you are assigned 2 gateways

Had a client ask me what would happen if you assigned 2 default gateways to a windows client?

My response was “Doesn’t matter what I think, let's find out”. I asked “Why would you ask?” and he replied that a consultant was over the other day and was telling the team that if you assign 2 default gateways to a windows 10 client, the client will use both in a load balancing/round-robin fashion.