Archive for the ‘Troubleshooting’ Category

Building “Intelligent” and Highly Automated Data Centers

Friday, February 19th, 2016

I’ve been fortunate to work in a space where I’ve had exposure to see and discuss infrastructure and architecture/design of some of the most highly utilized and scalable networks in the world. It’s fair to say living in Silicon Valley has definitely had a positive contribution as I’ve probably learned just as much outside of work as I have while on the job. (more…)

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Automating VLAN Configuration on Dell FTOS Switches via GVRP

Saturday, February 22nd, 2014

GARP VLAN Registration Protocol (GVRP) is a standards-based protocol defined in the IEEE 802.1Q specification that provides for automatic VLAN configuration on switches. The Generic Attribute Registration Protocol (GARP) is used by switches supporting GVRP to register/de-register attribute values such as VLAN IDs between switches within the network. GVRP is the standards-based equivalent to Cisco’s Virtual Trunk Protocol (VTP). To read more about Cisco VTP, read my prior blog at networkpros.org. For this blog, I utilize 2 x Dell S60s [FTOS 8.3.3.8 ]and 1x Dell S50N [FTOS 8.4.2.7]. Below is the network diagram for this lab. (more…)

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Dell PowerEdge M1000e – FlexAddressing

Friday, January 31st, 2014

Dell PowerEdge M1000e as shown with detected blade servers in the Dell M1000e Chassis CMC GUI

Dell PowerEdge M1000e as shown with detected blade servers in the Dell M1000e Chassis CMC GUI

Let’s say you have a Dell PowerEdge M1000e chassis populated with Dell blade servers with CNAs. Let’s also assume you enable FCoE on the CNA and utilize it for LAN and SAN traffic.

What if you were to use the CNA port’s WWPN (World Wide Port Name) within your zoning configuration on a backend Fibre Channel switch? What would occur if the CNA adapter went bad and needed to be replaced? Well, you would have to manually change all configurations that reference the LAN MAC Address or FC WWPN. In this case, the zoning configuration would have to be updated. This is where Dell’s M1000e FlexAddressing technology can help. (more…)

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LACP and Trunking Between Juniper JunOS and Dell FTOS Switches

Sunday, January 26th, 2014

In this blog I demonstrate how to configure a LACP LAG and 8021.Q trunking between Juniper JunOS switches and Dell FTOS switches. I will utilize 2 x Juniper EX4200-48T switches [JunOS 11.1R6.4] and a Dell S60 switch [FTOS 8.3.3.9]. Below is the network diagram for this lab. (more…)

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Changing the Root Password on Juniper JunOS Switches

Sunday, January 26th, 2014

In this short blog, I show how to easily change the root password on Juniper JunOS [JunOS 11.1R6.4] switches. It’s important to note, on a switch reset to default configuration, you can easily log into the switch with just the ‘root’ username without a password, however, you will not be able to ‘commit’ changes to the configuration until you set the root password; if you attempt to do so, you will get an error message stating “Missing mandatory statement: ‘root-authentication’error: configuration check-out failed: (missing statements)”. Below is a screenshot from a Juniper EX4200-48T displaying how to set/change the root password. (more…)

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Configuring a Syslog Server on CentOS 6.3 for Dell Force10 Switches

Thursday, July 11th, 2013

In this lab I’m going to demonstrate how to configure a syslog server to use with Dell Force10 switches. A syslog server can be used to store log files remotely on an external server. Syslog servers can be invaluable when troubleshooting. If a switch ever fails or reboots, no worries your logs are still available via the syslog server, and you can now analyse them to troubleshoot. An engineer can have multiple network devices write to one syslog file, or, if desired, a seperate syslog file can be created and stored remotely for each network device. (more…)

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Configuring OSPF with Multiple Areas

Friday, June 1st, 2012

In this lab, I use three Cisco 3725 routers [IOS 12.4(15)T10] to demonstrate how to setup OSPF with multiple Areas. Below is the network diagram for this lab. (more…)

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Setup and Troubleshoot EIGRP

Thursday, February 2nd, 2012

I discussed Enhanced Interior Gateway Routing Protocol (EIGRP) briefly in a prior blog, Load Balancing with EIGRP, however, in this lab I use two Cisco 3725 routers [IOS 12.4(15)T10] to demonstrate how to configure EIGRP; additionally, I’ll discuss some useful troubleshooting commands. Remember EIGRP is a Cisco proprietary routing protocol which allows for load balancing over equal and unequal links. When EIGRP is enabled, the router attempts to discover neighbors on interfaces by sending multicast EIGRP Hello messages via multicast address 224.0.0.10. The router then advertises to other neighbors about the subnets connected to its respective interfaces. Below is a diagram of the lab setup I will be using. (more…)

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OSPF Explained and Useful Troubleshooting Commands

Wednesday, January 4th, 2012

Open Shortest Path First (OSPF) is an open standard link-state routing protocol that supports multiple equal-cost routes to the same destination (four by default). OSPF constructs a shortest path tree and then updates the routing table with the best paths. In this blog I I will be explaining OSPF in the context of OSPF on Cisco routers, so I will be using Cisco IOS command syntax. For some of the commands I have included screenshots from a Cisco 2621XM [IOS 12.3(16a)] router. (more…)

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Tech Tips – Check if your E-mail Server is Running [Video]

Wednesday, December 7th, 2011

I created and uploaded this video to youtube back in 2009, but I thought it might be helpful for others if I post the link here. It’s just a simple video that shows you how you can use telnet to determine if your e-mail server is running. Telnet can be a great tool for troubleshooting connectivity and server issues. (more…)

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