Tag Archives: ACL

Basic Cisco Configuration

Following is a list of the most common Cisco device configuration commands that I am using when setting up a router or switch from scratch, such as hostname, username, logging, vty access, ntp, snmp, syslog. For a router I am also listing some basic layer 3 interface commands, while for a switch I am listing STP and VTP examples as well as the interface settings for access and trunk ports.

This is not a detailed best practice list which can be used completely without thinking about it, but a list with the most common configurations from which to pick out the once required for the current scenario. Kind of a template. Of course with IPv6 and legacy IP.

Continue reading Basic Cisco Configuration

IPv6 Dyn Prefix Problems

I am lucky to have a full dual-stack ISP connection at home. However, the ISP only offers a dynamic IPv6 prefix with all of its disadvantages (while no single advantage). In this post, I am summarizing the limitations of a dynamic prefix and some of the ideas on how to overcome them. I am always comparing the “IPv6 dynamic prefix” state with the legacy “dynamic IPv4 address” situation. I suppose that some of these problems will hit many small office / home office locations during the next years.

Of course, IPv6 ISP connections with dynamic prefixes should only be purchased at private home sites. It is no problem to have new IPv6 addresses there because all connections are outbound. However, many small remote offices (SOHO) might rely on such cheap ISP connections, too. If they provide some servers in a DMZ or other components such as network cameras, building components with IPv6 connections, etc., they will run into these kind of problems. (The remote office could even tunnel every outbound IPv6 traffic through a VPN to the headquarter. But if it wants to use a local breakout, this won’t be an alternative.)

Continue reading IPv6 Dyn Prefix Problems