Category Archives: Networking

Troubleshooting Boot Loader Prompt for Nexus 9K

If the system boots and falls into “loader>” prompt. Do the following steps. Step 1: Issue the command dir to check the directory and enter the command:boot nxos.9.2.1.bin ​ Step 2: Once the switch is boot up, set password for Nexus 9K, Step 3: Login to the switch. How to prevent Nexus 9K from dropping into “loader >” promptAs… Read More »

How to Run 40GbE Over Duplex LC MMF Cabling

This is a good guide for running 40G on existing MMF fiber. The use of parallel optics in 40GbE multimode fiber cabling (MMF cabling) require more fiber strands than the 10GbE infrastructures. Thus, data center will require a cabling upgrade to meet the requirement of migration. In this case, cost is a big factor. To… Read More »

Default routes in BGP

There are 3 ways of advertising default route in BGP. Method 1: Using network 0.0.0.0 command. It requires only that the route 0.0.0.0 is present in the Interior Gateway Protocol (IGP) routing table. This is the preferred approach. Method 2: Using default-information originate command. It requires explicit redistribution of the route 0.0.0.0. This protects against… Read More »

Arista EOS 101

This is a simple short notes taken from Arista Configuration Essentials (ACE) Lab Guide CLI & BASH Enter bash switch# bash switch-bash$ ifconfig -a switch-bash$ top switch-bash$ cd /mnt/flash Upgrade EOS Upload EOS to switch switch# copy http://1.1.1.1/EOS/EOS-4.15.5M.swi flash: Verify image switch# dir flash: Configure boot image switch# boot system flash: EOS-4.15.5M.swi Verify boot-config switch#… Read More »

FIB vs RIB

Terminology: RIB – Routing Information Base FIB – Forwarding Information Base RIB This is a routing protocols database of routing prefixes that could potentially be installed in the routing table. Derived from the control plane, it is not used for forwarding. Every protocol such as OSPF, EIGRP, BGP has its own RIB and select their… Read More »