Author Archives: advanxer

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 »

Arista – dealing with inactive routes in BGP

In EOS, BGP implementation normally considers only active routes in RIB for advertisement to its peers. In certain deployments, IGP protocol like OSPF may carry same set of prefixes as BGP (especially if we use OSPF to form iBGP). In addition, routes from OSPF and BGP may be mutually redistributed. As a result, when local… Read More »

Arista EOS – BGP remove-private-as

This is a post copied/stolen/updated from Kevin Wang’s wiznote – [EOS] [RFC6996] BGP remove-private-as.  Summary: Feature support starts from 4.19.1F and 4.18.4F “remove-private-as” works for both 2B/4B AS#.  Private AS number: 64512-65534(2B), 4200000000-4294967294(4B). convert to asdot notation is 64086.59904. “neighbor x.x.x.x remove-private-as” only works for those as-path which only have private as number present. 3. In… Read More »

BGP as-path regular expressions

A regular expression is the character pattern that can be matched against an input string. Regular expressions can be built using letters (A through Z, a through z), numbers (0 through 9) and other keyboard characters, such as the exclamation point (!) or a tilde (~). A regular expression can be a single-character pattern or… Read More »