All overlay virtual networking solutions look similar from far away: many provide layer-2 segments, most of them have some sort of distribut...
Showing posts with label IP routing. Show all posts
Showing posts with label IP routing. Show all posts
Deutsche Telekom TeraStream: Designed for Simplicity
Almost a year ago rumors started circulating about a Deutsche Telekom pilot network utilizing some crazy new optic technology . In spring I’...
Can BGP Route Reflectors Really Generate Forwarding Loops?
TL&DR Summary: Yes (if you’re clumsy enough). A while ago I read Impact of Graceful IGP Operations on BGP – an article that described h...
What Exactly Is The Control Plane?
Tassos opened an interesting can of worms in a comment to my Management, Control and Data Plan es post: Is ICMP response to a forwarded pa...
TTL in Overlay Virtual Networks
After we get rid of the QoS FUD, the next question I usually get when discussing overlay networks is “ how should these networks treat IP TT...
The Intricacies of Optimal Layer-3 Forwarding
I must have confused a few readers with my blog posts describing Arista’s VARP and Enterasys’ Fabric Routing – I got plenty of questions a...
Migrating a cold VM into a foreign subnet
Moving a running VM into a foreign subnet is Mission Impossible due to stale ARP entries (anyone telling you otherwise is handwaving over ...
Enterasys Host Routing – Optimal L3 Forwarding with VM Mobility
I spent the last few weeks blogging about the brave new overlay worlds. Time to return to VLAN-based physical reality and revisit one of the...
Virtual Appliance Routing – Network Engineer’s Survival Guide
Routing protocols running on virtual appliances significantly increase the flexibility of virtual-to-physical network integration – you can...
Routing Protocols on NSX Edge Services Router
VMware gave me early access to NSX hands-on lab a few days prior to VMworld 2013. The lab was meant to demonstrate the basics of NSX, from ...
Optimal Layer-3 Forwarding with Active/Active VRRP (Enterasys Fabric Routing)
Enterasys implemented optimal layer-3 forwarding with an interesting trick: they support VRRP like any other switch vendor, but allow you t...
The Difference between Access Lists and Prefix Lists
A while ago someone asked what the difference between access and prefix lists is on the Network Engineering Stack Exchange web site (a fant...
VRRP, Anycasts, Fabrics and Optimal Forwarding
The Optimal L3 Forwarding with VARP/VRRP post generated numerous comments, ranging from technical questions about VARP (more about that in ...
Optimal L3 Forwarding with VARP and Active/Active VRRP
I’ve blogged about the need for optimal L3 forwarding across the whole data center almost a year ago when I introduced it as one of the int...
Evolution of IP Model
I stumbled upon a fantastic RFC - Evolution of IP Model (RFC 6250) - that should be made mandatory reading for everyone remotely involved w...
How would you like to configure Policy-Based Routing (PBR)
Adam Sweeney , VP of EOS Engineering @ Arista Networks posed me a challenging question after my I-so-hate-PBR-CLI rant : “ Is there somethi...
Redundant Data Center Internet Connectivity – Problem Overview
During one of my ExpertExpress consulting engagements I encountered an interesting challenge: We have a network with two data centers (con...
IP packet delivery confirmation
Thomas wanted to check whether the IP traffic is actually delivered to a remote site and sent me the following question: I would like to kno...
Is Layer-3 DCI Safe?
One of my readers sent me a great question: I agree with you that L2 DCI is like driving without a seat belt. But is L3 DCI safer in case of...
Disabling IP unreachables breaks pMTUd
A while ago someone sent me an interesting problem: the moment he enabled simple MPLS in his enterprise network with ip mpls interface confi...