Category Archives: Networking

Cisco IOS VTI

The use of Internet Protocol Security (IPsec) Virtual Tunnel Interfaces (VTIs) simplifies the configuration process when you must provide protection for site-to-site VPN tunnels. A major benefit of IPsec VTIs is that the configuration does not require a static mapping of IPsec sessions to a physical interface. IPsec VTI’s function like any other real interface… Read More »

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 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 »