Installing and Configuring OpenvSwitch on Ubuntu 12.04 (Precise Pangolin)
Quick install how to for Installing and Configuring OpenvSwitch on Ubuntu 12.04 (Precise Pangolin) with the nightly OVS build. Before I start, I must point out the great progress the dev team has done in such a short time. All of the old gotchas in earlier releases on implementation are long gone. I am going to revisit the KVM integration …
Juniper Default Routing Tables
The first time I saw these I remember thinking what is going on here. It can be pretty foreign the first time someone sees it especially coming from Cisco IOS. The two CLIs wrap and abstract the underlying standardized frameworks pretty differently. I think it helps to decouple what the function of the table is before ever operating the gear. …
Juniper and Cisco Comparisons of RIB, LIB, FIB and LFIB Tables
A quick overview before we start: It starts off with the ingress packet. As a packet comes into the Label Edge Router (LER) the Layer2 frame header will be examined and forwarded to the appropriate table, based on the Ethertype field to determine what protocol in payload of the Ethernet frame. The table interactions in principle are the same between …
Basic MPLS/VPN with Cisco IOS
This is a quick tutorial for basic MPLS/VPN with Cisco IOS configuration. The tutorial exemplifies basic PE to P to PE configuration on three Cisco 7200s running in GNS3 with IOS. R2 is configured as a route reflector P node and R4, R6 and R3 are PE node route reflector clients. The IGP is OSPF with R2 as the ABR. Loopback1 …
How Headers Encapsulate in the OSI stack
How Headers Encapsulate in the OSI stack: Part 2 of some refreshers. We send application data or payload by encapsulating or framing each layer within the previous layer. We looked at each one individually and now here is how they look when each layer is wrapped inside the previous layer. Figure 1. Here is how application data gets passed to each …
What are Ethernet, IP and TCP Headers in Wireshark Captures
If I could go back in time when I was a n00b kid wanting to go from zero to a million in networking, the one thing I would change would be spending about 6 months on the fundamentals of networking headers and framing before ever touching a single peice of vendor gear. Ethernet, IP and Transport headers (L2-L4) are the …
Why the NOS will decouple
Over the next couple of years some of us expect the networking industry to have some fairly significant changes. There are really two options: A distributed approach we have today or a controller based centralized model. We have today just that, autonomous devices building adjacencies to one another, exchanging what it hopes are the best healthy paths to send next hop traffic …
OpenVswitch and GRE tunnel notes
Here is a quick post for setting up GRE tunnels on OpenVswitch. Both Vswitch boxes are attached to an OpenFlow Beacon controller. More up to date how-to can be found here: Configuring VXLan and GRE tunnels on OpenvSwitch KVM live storage migration makes an interesting story and run at VMware tools. The dreaded layer2 data center link conversation may never …
