Posts about TCP/IP, Ethernet, network troubleshooting, traffic analysis, and general networking.
The ARP Probe frame
The IPv4 Duplicate Address Detection process.
PKTMON part 1: The native Windows packet capture tool
Introduction to the PKTMON tool.
PKTMON part 2: Building the filters
Learn how to construct useful filters to collect the relevant traffic.
PKTMON part 3: Using pktmon in a tcpdump-like mode
Run PKTMON live on the command line.
PKTMON part 4: Overview of running on the command-line
Summery information on how to run PKTMON in real-time mode.
PKTMON part 5: Capture packets for offline analysis with Wireshark
Learn how to convert the capture file into the PCAP format.
PKTMON part 6: View live network counters on the command line
Display live counters for particular protocols.
PKTMON part 7: View CDP and LLDP on the Windows command line
Detect the physical server’s connection to the exact switch port.
PKTMON part 8: Analyze packets in text format.
View captured PKTMON data in text files with various levels of detail.
PKTMON part 9: Troubleshooting DNS.
Learn to interpret the PKTMON insightful output of DNS queries and replies.
PKTMON part 10: Troubleshooting TCP.
Use the detailed PKTMON output to troubleshoot TCP issues.
The Ethertype value, part 1
To understand the specific usage of the Ethertype field
ESXi virtual machine network statistics
How to read “show interface” like statistics from the virtual switch
VMware virtual network interface cards – part 1
The difference between emulated and paravirtualized network adapters.
VMware virtual network interface cards – part 2
Performance tests between VMXNET3, E1000E and the E1000 virtual adapters.
Quickly access the network settings through ncpa.cpl
The best way to reach the network card settings in Windows.
IPv6: ICMPv6
The basic workings of ICMPv6 in IPv6.
The IPv6 header
Describe the content of the IPv6 packet header.
The VLAN 802.1Q tag – part 1
How the 802.1Q tag fits into an Ethernet frame and which headers are modified.
The tcpdump-uw tool
Use the tcpdump-uw packet sniffer and learn the useful parameters.
Actual throughput on Gigabit Ethernet
How to calculate the actual bandwidth on a Gigabit network.
The NC port scanner tool
Using the NC tool to do port scanning from ESXi.
Ethernet Flow Control
How to activate and verify Flow Control on HP Procurve switches.
Test network performance with the Iperf tool
Use Iperf to control network throughput and TCP performance.
BDPU Guard
How to enable the new security feature of Spanning Tree BPDU Guard/Filter in ESXi.
LACP and ESXi
How to configure LACP in VMware ESXi
Troubleshooting Jumbo Frames
The correct parameters to verify Jumbo Frames networking in Windows and ESXi.
Different Jumbo Frames settings on the same VLAN
How the MSS negotiation process in the TCP three way handshake makes this possible.