Links for 2007-07-19

Delicious Bookmarks

• How to: Upgrade to vSphere 4.1
  Step-by-step process for upgrading. A huge caveat is that vCenter 4.1 requires a 64-bit OS and thus a DB migration.
• Nexus 7000 Training Documentation
  Some terrific (3rd party) introduction documents to the Nexus 7000 platform.
• Enable ICMP (Ping) with the Server 2008 Firewall
  Quite annoying that Win 2008 doesn't allow ICMP by default. Here's how to turn it back on so monitoring works properly.
• Converting lvm to a normal partition
  There's no easy way to do it, but here's a less-easy one. Need to do this to many machines, since mbralign doesn't support LVM.
• GNU Parallel
  Shell tool for running a job on multiple lines of input in parallel, either locally or on remote machines.
• 6 Command Line Tools for Linux Performance Monitoring
  Some interesting tools I hadn't heard of, in the same vein as 'top' but with more features.
• OSPF Fast Convergence | CCIE Blog
  Really, really in-depth discussion of tuning OSPF to minimize convergence/failover time.
• VMware Snapshots 101
  How VMDKs and snapshots actually work at a low level, along with some best practices.
• Understanding TCP Sequence and Acknowledgment Numbers
  Terrific use of Wireshark to deep-dive into the individual packets of a TCP session to see how the flow works.
• VLAN Security White Paper  - Cisco Systems
  Covers most of the common ways to attack/exploit VLANs, along with how to protect against them (when possible)
• Mac Configuration Management at Los Alamos National Laboratory (PDF)
  Puppet is more-and-more becoming the Mac bulk administration tool of choice. Google uses it too.
• Practical, Visual, Three-Dimensional Pedagogy for Internet Protocol Packet Header Control Fields
  A long-winded way of saying "building the TCP and IP packet headers using Lego. Awesome
• Tradeoffs between scalability and performance in UCS
  One Cisco UCS system can scale to between 80 and 122 blades, depending on uplink oversubscription.
• How to Get Catalyst Switch Backplane Utilization Using SNMP
  Aggregate bandwidth across all modules. Doesn't seem to be possible on the 4500, unfortunately.
• Port forwarding a range of ports on Cisco IOS
  Using an ACL with a one-IP address pool to automatically forward multiple ports.