Installing Intel Omnipath 100G on Centos 7

Intel Omnipath is 100G fabric a less expensive alternative for Mellanox 100G.. we recently bought 10 Racks of servers with 100G Omnipath .

Until recently there is NO driver for Ubuntu , but i love centos so i kicked that in ..


Introduction to Intel® Omni-Path Architecture

Intel OPA is the latest generation of Intel’s high-performance fabric technology. It adds new capabilities to enhance high-performance computing performance, scalability, and quality of service. The Intel OPA components include Intel OP HFI, which provides fabric connectivity, switches that connect a scalable number of endpoints, copper, and optical cables, and a Fabric Manager (FM) that identifies all nodes, provides centralized provisioning, and monitors fabric resources. Intel OP HFI is the Intel OPA interface card which provides host-to-switch connectivity. Intel OP HFI can also connect directly to another HFI (back-to-back connectivity). Continue reading

the following resource is signed with a weak signature algorithm md5withrsa

So, after some digging, I just found a quick (but temporary) solution:

Just comment out the setting of “jdk.jar.disabledAlgorithms” in the file of”lib/security/” (which is located at “/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/lib/security/, on my MacOS 10.12)

# jdk.jar.disabledAlgorithms=MD2, MD5, RSA keySize < 1024

After that, the JNLP file will be running as usual again.

How Vlan works in plain language

To understand how VLANs work, let’s consider VLAN applications in a traditional IT environment, where physical hosts are attached to a physical switch, and no virtualization is involved. Imagine a scenario where you want three isolated networks but you only have a single physical switch. The network administrator would choose three VLAN IDs, for example, 10, 11, and 12, and would configure the switch to associate switchports with VLAN IDs. For example, switchport 2 might be associated with VLAN 10, switchport 3 might be associated with VLAN 11, and so forth. When a switchport is configured for a specific VLAN, it is called an access port. The switch is responsible for ensuring that the network traffic is isolated across the VLANs.

Now consider the scenario that all of the switchports in the first switch become occupied, and so the organization buys a second switch and connects it to the first switch to expand the available number of switchports. The second switch is also configured to support VLAN IDs 10, 11, and 12. Now imagine host A connected to switch 1 on a port configured for VLAN ID 10 sends an Ethernet frame intended for host B connected to switch 2 on a port configured for VLAN ID 10. When switch 1 forwards the Ethernet frame to switch 2, it must communicate that the frame is associated with VLAN ID 10.

If two switches are to be connected together, and the switches are configured for VLANs, then the switchports used for cross-connecting the switches must be configured to allow Ethernet frames from any VLAN to be forwarded to the other switch. In addition, the sending switch must tag each Ethernet frame with the VLAN ID so that the receiving switch can ensure that only hosts on the matching VLAN are eligible to receive the frame.

A switchport that is configured to pass frames from all VLANs and tag them with the VLAN IDs is called a trunk port. IEEE 802.1Q is the network standard that describes how VLAN tags are encoded in Ethernet frames when trunking is being used.