Cisco announced recently a replacement program for their B440 blades (M1 and M2)
http://www.cisco.com/en/US/ts/fn/634/fn63430.html
Something I noticed on the front of each blade, where the model is shown, the new generation blades (replacements) have the black background with the silver text, shown as the top blade on the picture below:
However, the old blades still have the black text with no background. An interesting way to identify the newer generation of hardware.
If you’ve set up an ESXi host, you’ve likely seen this screen:
This allows you to configure which VLAN is used for management. But what does this really do? Time after time I run into very smart engineers that primarily work on virtualization and not as much on the physical networking side - and they miss a few of the networking fundamentals that those of us that were brought up in ROUTE/SWITCH know and love.
It’s been a while since I’ve done a review of anything on the site and since I’d rather continue to make use of the category than delete it, I decided to share a piece of software I recently discovered that’s helping make my life easier.
Remote Desktop Connection Manager is essentially just that - it manages remote desktop connections. However, it does it in a way that I find appealing and EASIER to use than the native client or other organizational methods out there.
For those that have worked with any type of blade server system, you know that boot from SAN is just about the coolest thing since sliced bread. Cisco UCS makes this even cooler by integrating with the service profile concept, allowing for stateless compute provisioning across the board.
I’ve done boot from SAN many times, but never with Windows. I’ve primarily used ESXi4.1 or ESXi5.0 stored on a Fibre Channel LUN, then the VMs are stored in either a FC or NFS datastore.
Snapmirror is a Netapp feature that’s pretty commonly used to copy data from one system to another. You can copy volumes, or qtrees. It’s also very useful in Disaster Recovery plans, since volumes can be incrementally backed up to an offsite location.
I have a VMWare vCenter instance running on Cisco UCS that utilizes a Fibre Channel LUN to store VM templates. It’s pretty large, since it holds templates for a variety of operating systems.
I recently observed some strange behavior with Cisco UCS Manager. When I visited the web page that allows me to download the .jnlp file that launches UCSM, it came up just fine. But when I clicked on “Launch UCS Manager” to actually launch this applet, the splash screen showed briefly, but disappeared after a few seconds, never to be seen again.
Eventually, you might also see some java error messages that say something like
I’m currently working with a relatively large Cisco UCS installation. Initially, the system was installed and brought up to relatively recent levels of firmware, but a mismatch in the way that the firmware packages were set up in various sub-organizations on some of the UCS systems caused some of the blades to retain the old version of firmware on the M81KR adapters and the CIMC controllers.
Due to the scope of the installation, I wanted to ensure that the blades were able to continue operating while I made my changes.
I would like to share some tips regarding gadgets that I believe every Datacenter Network Engineer should have with them. There are several, but I want to bring up my top two.ß
Travel Router I am often in situations where it is either difficult or impossible to manage Nexus switches and/or UCS remotely. Pick your reasons - sometimes the management network doesn’t exist (yet) or there are heavy security measures in place that restrict wired management, whatever.
Static routes can be handy in some situations where you want to do some quick and (sometimes) easy routing to get the job done, whether replacing the job that a routing protocol would perform, or redistributing the static route into that protocol.
The best way to do this would be to identify the remote subnet being routed to, and specify a next-hop IP address to send traffic to so that it can be reached.
I ran into a configuration recently where I had a Netapp storage array with the UTA cards installed, so there two CNA ports on each filer for a total of 4 ports. However, instead of a dual-switch design, there was only a single Nexus 5000, and therefore, no vPC configuration. I needed to achieve some level of redundancy on an interface level, but ran into some problems which I’ll discuss.
Port-Channels, are a way of aggregating physical links together so that you can load balance traffic over each link to increase bandwidth, and create more redundancy. You might commonly see this configured between two switches, as shown below:
Each link works together to form a logical, loop-free interface. These are relatively commonplace, and in this scenario highly useful because it prohibits spanning tree from blocking one of these ports, allowing the switch to utilize each link.
It’s interesting to me to see the differences in infrastructure products as it pertains to out of the box, or default configuration. Take for instance, the relationship between a firewall and a switch. Your average firewall is configured “closed”, meaning that if you want to allow anything, you have to explicitly allow that certain type of traffic. If you do not, it is not allowed. A switch, on the other hand, is configured to be functional above all, out of the box.
Port mirroring is a very valuable troubleshooting tool. Cisco calls this SPAN, and it’s pretty easy to do. Cisco’s NX-OS platform does it a little differently than traditional IOS, so I wanted to briefly post a walkthrough.
First, you have to set up the monitor session and configure source and destination interfaces:
switch(config)# monitor session 1 switch(config-monitor)# source int port-channel 2 both switch(config-monitor)# source int port-channel 3 both switch(config-monitor)# destination interface ethernet 1⁄7 switch(config-monitor)# no shut switch(config-monitor)#
I found a bug in the vHBA Template creation screen on Cisco UCS 2.0.
It’s not too bad, but still a little annoying, and can cause you to have some problems depending on how you have your VSANs set up.
If you notice, the default VSAN is selected for my vHBA template. I have named my VSANs “fabric-a” and “fabric-b”. If I drop down the VSAN selector, I have the ability to select the VSAN I have associated with fabric A:
My time lately has been just blasted. I’m being placed into new projects with a large company that involves just about every technology found in a datacenter, and as a result, my spare time is….nonexistent.
My knowledge levels in many areas continues to increase, and my need to spew some of it onto the internet in the form of helpful posts, or opinions is not quenched, but unfortunately I do not have a ton of time to dedicate to full-on blog posts during the week.
Cisco switches (and the vast majority of other vendors) ship their switches with all ports in the enabled state. This allows someone with no networking background to plug stuff in, the switch starts learning MAC addresses, and everything works just fine. Sometimes it’s necessary from a security perspective to change this default behavior, so the network engineer is forced to “no shut” every port he or she wishes to use.
I was recently asked whether or not I preferred to use a router redundancy protocol like HSRP, VRRP, or GLBP, or stack switches together to form a sort of “virtual router”, and use that for redundancy. Just like anything else, the immediate answer is “it depends”, but there are a few things to remember when considering a redundant design with your routers or Layer 3 switches.
First, redundancy protocols can be found nearly everywhere.
First, I’d like to thank you all for continuing to read my thoughts these last few weeks. Some already know that I passed the CCNP ROUTE exam this past weekend, and that has slowed my ability to write consistently. Fortunately, I laid that beast of an exam to rest and I get to focus on bigger, better things.
I’ve been working a project for the past few weeks that’s involved the integration of HP and Cisco networking equipment.
I recently listened to Packet Pushers Show 72 on “How we are killing the internet” and want to voice my thoughts on the topics discussed.
The majority of the conversation circled around IPv6 adoption, and the state of the internet in light of the existence of tunneling mechanisms being used. Ivan mentioned that we are destroying the internet with all the tunnels (PPPoE, PPPoA, 6to4, 4to6, 6rd, etc) and translation points.
I had heard of CloudShark a while back but was reminded of it by a recent Packet Pushers article. For those that haven’t, CloudShark is a new product that basically claims to be a cloud-based capture file (such as from Wireshark) archiving solution. Viewing the main CloudShark website, you’ll be unable to miss what is obviously their big pull - CLOUDSHARK BRINGS YOUR CAPTURE FILES TO THE CLOUD OMGZ!!! (Did the fact that those words are at the top of each page on their site not give away their enthusiasm?
Matt Oswalt