Routing in the Data Center

Types of Routes: Direct Route – Directly attached to the router interface. Static Route – Used to tell your router statically where to direct traffic: ip route 10.10.30.0/24 10.10.10.100 Meaning 10.10.30.0/24 can be reached via 10.10.10.100.  This can be confirmed by viewing the routing table with: show ip route Dynamic Route – Determined using a… Read More »

NX-OS – Layer 2 Redudancy

Layer 2 redundancy protocols exist to prevent loops from broadcasts and do so using BPDU packets.  These protocols include: STP – Spanning Tree Protocol – 802.1D RSTP – Rapid Spanning Tree Protocol – 802.1W MSTP – Multiple Spanning Tree Protocol  – 802.1S LAN Port Channeling – Also known as EtherChannels to bind multiple ports together.… Read More »

Using NX-OS for beginners

To show all commands in your buffer history: show cli history This command used to be show history on the old OS. Some enhanced editing shortcuts include: Ctrl+A – to get to the beginning of the line Ctrl+E – to get to the end of the line Ctrl+B – moves one character to the left… Read More »

Handy Linux Commands

ps -eaf | grep nginx Used to determine where the process is using config files from. If you need to know where NGINX is pulling its command from, run this command. You can change ‘nginx’ to tomcat or apache or whatever you may need to find. lsof -i TCP:80 Used to determine open files being… Read More »

Troubleshooting DNS – DNSLint

DNSLint is a very robust tool provided for free by Microsoft that allows you to troubleshoot DNS issues more effectively.  It has many options, and can even pull useful information from external zones (not just AD integrated zones).  When you pull information using this tool, it will create an HTML report in your working directory… Read More »

Implementing Microsoft Dynamic Access Control (DAC)

Understanding DAC: New access control method for file system resources used for Access Control, Auditing , and FCI (File Classification Infrastructure).  Still based off of (Authentication/Authorization/Auditing). Works as a layer on top of NTFS and Share permissions. Multiple benefits including Protecting (encrypting) sensitive information, compliance and data analysis, and access denied remediation. Windows 7 can… Read More »

Fix Yum Database problems

If you are having yum update or yum install problems and getting errors like this: rpmdb: Thread/process 17818/140028542469888 failed: Thread died in Berkeley DB library error: db3 error(-30974) from dbenv->failchk: DB_RUNRECOVERY: Fatal error, run database recovery error: cannot open Packages index using db3 – (-30974) error: cannot open Packages database in /var/lib/rpm CRITICAL:yum.main: Then you… Read More »