Posts about TCP/IP, network hardware, traffic analysis and general networking. The most recent articles are on the top.

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 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 5.1.

LACP and ESXi 5.1

How to configure LACP in VMware ESXi 5.1.

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.