Tag: networking

Rapid PVST+ Spanning-tree Summary

Rapid-spanning-tree is an enhanced 802.1d standard. The differences: Only waits for 3 missed Hello’s instead of 10 Hello’s (maxage timer) Transitioning from disabled state to learning state (skipping the Listening state) uses some other port types Max Age Max Age is refreshed every time the port receives a BPDU PVST                     i.        non-designated ports will …

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Network Virtualization Careers In-Depth Interview – Nemtallah Daher – #VirtualizeYourNetwork

Nemtallah Daher is Senior Network Delivery Consultant at the consulting firm AdvizeX Technology.   What made you choose to get certified in network virtualization? About a year ago, I decided I needed to challenge myself a little bit more. I … Continued Source: Network Virtualization Careers In-Depth Interview – Nemtallah Daher – #VirtualizeYourNetwork – Original …

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Permanent link to this article: https://daherlabs.mywire.org/wordpress/?p=619

Encapsulation Overhead

There are variuos methods to encapsulate and tunnel traffic.  Each one of these protocols adds an “envelope” to the packet which means more overhead and a bigger packet size.  Here are a few of these protocols:   Protocol Overhead Bytes IP 20 UDP 8 TCP 20 802.1Q 4 OTV 42 VXLAN 50 STT 54 GRE …

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EIGRP Stub Statement

EIGRP – Stub Routing Stub routing is an EIGRP feature primarily designed to conserve local router resources, such as memory and CPU, and improve network stability. The stub routing feature is most commonly used in hub-and-spoke networks. This feature is configured only on the spoke routers. When configured on the spoke router, the router announces …

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Permanent link to this article: https://daherlabs.mywire.org/wordpress/?p=597

The Goal is Worth the Journey

On August 5, 2014, I attempted my first VCDX defense on network virtualization in Reston VA.  It was a culmination of 4 months of hard work and sleepless nights.  I even sent my family away on vacation half way around the world, so I can study and prepare without interruption.  During my defense, I was …

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Permanent link to this article: https://daherlabs.mywire.org/wordpress/?p=443

HP Switch Commands

Someh helpful commands from my colleague Mitch Vaughan at AdvizeX   ·       show running-config   o   this will show the current running configuration of the device   ·       show config status   o   This will indicate if the running configuration differs from the startup configuration   ·       write memory   o   Copy the running-configuration to …

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Permanent link to this article: https://daherlabs.mywire.org/wordpress/?p=439

PVST+ Spanning-tree Summary

Roles Bridges: root non-root Ports: Root Port (RP) Designated Port (DP) Non-designated Port (NDP)   Overview For each VLAN choose one root bridge The switch with the lowest Bridge ID (BID) BID consists of 4-bit priority value (multiple of 4096) + 12-bit VLAN ID + MAC address Priority defaults to 8 (8 * 4096 = …

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Permanent link to this article: https://daherlabs.mywire.org/wordpress/?p=311

How OSPF Works

How OSPF establishes a neighbor OSPF routers send Hello packets to declare their presence on a network segment and listen for other routers. These Hellos are either multicast to 224.0.0.5 or unicast by static configuration. After OSPF router receives a Hello packet from a neighboring router on the same segment, it performs a series of …

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Permanent link to this article: https://daherlabs.mywire.org/wordpress/?p=133

OmniOS General Networking Commands

General OmniOS networking commands taken from the OmniOS site. Setting up dynamic (DHCP) networking # First identify the physical interface on which you would like networking: # dladm show-phys LINK MEDIA STATE SPEED DUPLEX DEVICE e1000g0 Ethernet unknown 0 half e1000g0 e1000g1 Ethernet ? 1000 full e1000g1 Physical interfaces that don’t have a corresponding IP interface …

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Permanent link to this article: https://daherlabs.mywire.org/wordpress/?p=127

Create Etherchannel, VLANs on Solaris and Cisco

Here is a quick guide on how to create an LACP etherchannel and add VLANs to that etherchannel.   Current System   root@csu-s:~# ifconfig -a lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1         inet 127.0.0.1 netmask ff000000  e1000g0: flags=1000842<BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 4         inet 0.0.0.0 netmask 0      …

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