Introduction to Docker
Docker and more generic Linux containers technology are a hot topic these days. The website says “for developers and sysadmins”, I am neither of the two but I can still find some useful applications for containers as a Network Engineer.…Ciena Turns Acquirer, Offering $335M for Cyan Inc.
Amid chatter that it could be acquired by Ericsson, Ciena pounces first.
Cisco CEO John Chambers to Retire, Chuck Robbins Named as Successor
The Chambers Era is coming to a close after more than 20 years.
SDx (Software-Defined Everything), The Future of Infrastructure – An Introduction
We’re kicking off an eight-part series on SDx (software-defined everything) and the future of infrastructure. Learn what SDx is and stay competitive in a software-defined world.
Epic Clashes in a Virtualized Data Center Near You
Debunk the myth of hardware independence in a software-defined world.
Cisco’s Has a New CEO as John Chambers stays on.
John Chambers steps down as CEO, remains Executive Chairman & Chairman of Board. Chuck Robbins, sales & operations executive, will become CEO suggesting not much will change. Some thoughts and speculation.
The post Cisco’s Has a New CEO as John Chambers stays on. appeared first on EtherealMind.
When Small Gets Big in a Hurry: How to Manage Fast-Growing Networks
by Keith Tokash, originally published on the Auvik blog In the last few years I’ve helped grow the networks — including theOwn the Problem
In the late 1990’s, I was on the routing protocols TAC team in Raleigh — which means I answered the phone, and said things like, “This is Russ from Cisco TAC, how can I help you?” Generally what followed was a crash, or, well, just about anything. The design on the left is what we had on the back of our shirts — including what we called ourselves, the Gateway of Last Resort.
Of course it’s a play on words, as you might imagine — where does a host send traffic it doesn’t know what to do with? The gateway of last resort. And what is the gateway of last resort? A router. And what the RP team worked on was, well, routers. But there’s another reason we adopted this slogan for ourselves — because it was, generally speaking, how the CRC (the folks who took the initial call and figured out which backline team to hand it off to) conceived of our little team. The PIX, the 7200, VIP cards, crashes, hangs, tracebacks, any sort of routing protocol problem, lots of hardware problems, anything to do with the forwarding path, memory fragmentation, and just about anything else. A Continue reading
Walking with Packets: Traceroute Through MPLS Cloud
Think about this for a minute: An MPLS network with a two Provider Edge (PE) routers and some Provider (P) routers. The P routers have no VRFs configured on them and therefore have no routes whatsoever for any of the customer networks. A customer then does a traceroute from one of their sites, across the MPLS cloud, and into one of their other sites. The traceroute output shows the P routers as hops along the path.
How is it possible for the P routers to reply to the traceroute if they don’t have routes back to the customer network?
The Lab Setup
Here’s the network:
Click to Enlarge
Here’s the traceroute output from R21’s loopback0 to R8’s loopback0 (the last octet of each IP address corresponds to the name of each router):
R21#traceroute 10.1.8.8 source loopback0
Type escape sequence to abort.
Tracing the route to 10.1.8.8
VRF info: (vrf in name/id, vrf out name/id)
1 10.4.4.4 21 msec 18 msec 17 msec
2 10.2.45.5 [MPLS: Labels 21/24 Exp 0] 19 msec 18 msec 18 msec
3 10.2.15.1 [MPLS: Labels 21/24 Exp Continue reading