Cisco Archives - j2sw Blog

Switch VLAN configuration de-mystified

There seems to be a great deal of confusion when it comes to VLAN configuration across different platforms. In this article, I am going to clarify some often misunderstood terms and bad configurations I see. Let’s start with some terms Tagged Frame – A tagged frame includes a VLAN ID in the header. Untagged Frame – A frame that does not include and VLAN ID in the header. If you are unfamiliar with ethernet frame here is a good definition https://www.ionos.com/digitalguide/server/know-how/ethernet-frame/ or https://en.wikipedia.org/wiki/Ethernet_frame...

July 10, 2022 by j2sw Cisco Equipment

Auto mapping your Cisco Network

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Running Docker inside Cisco Catalyst 9000

https://blogs.cisco.com/networking/application-hosting-on-catalyst-9000-series-switches Catalyst 9000 series of switches, Cisco’s flagship enterprise switching portfolio delivering Intent Based Networking (IBN) runs a modern, modular and model-driven operating system stack, Cisco IOS® XE. Powered by Intel x86 CPU, Catalyst 9000 series now supports secure Docker™ container based application hosting environment, starting with the Catalyst 9300 switches. Users now have the option to either build their own apps or host any off-the-shelf apps to enable network monitoring/troubleshooting, security or IoT related outcomes.

November 9, 2021 by j2sw Cisco Equipment

BGP, a single /24 and two diverse non-connected exit points

I am starting to see the following scenario more and more as IPv4 space is hard to get, but isn’t. With ARIN it is still possible to get an IPv4 allotment. Many smaller ISPs qualify for a /24 and can get one if they wait long enough on the ARIN waiting list. a /24 of IPv4 space is the smallest block that 99% of the Internet allows to be advertised on the Capital I Internet. There are filter rules in place that drop...

November 26, 2020 by j2sw BGP Cisco Equipment Mikrotik Networking WISP xISP

Cisco Syslog severity levels

For those of you implementing Syslog triggers and such the following list will be helpful in filtering and classifying Syslog entries. 0 – Emergency 1 – Alert 2 – Critical 3 – Error 4 – Warning 5 – Notice 6 – Informational 7 – Debug

August 3, 2020 by j2sw Cisco Equipment

Preseem and Switches in switch centric design

Anyone who follows me knows I am a big fan of switch centric designs. This usually involves a router on a stick paired with a high port count switch. Recently I had a client that installed a Preseem appliance in their network. Equipment used in this setup-Dell R710 with a 4 Port SFP+ card running Preseem-Cisco 3064-X 48 Port switch-Maxxwave Vengeance router with dual QSF+ card and 4 Port SFP+ card A visio diagram of how this looks We have two transport links...

July 28, 2020 by j2sw Cisco Equipment Gear Networking switching Tips

Cisco switching

April 21, 2020 by j2sw Cisco Equipment Gear switching

Learning, Certifications and the WISP

One of the most asked questions which come up in the xISP world is “How do I learn this stuff?”. Depending on who you ask this could be a lengthy answer or a simple one-sentence answer. Before we answer the question, let’s dive into why the answer is complicated. In many enterprise environments, there is usually pretty standard deployment of networking hardware. Typically this is from a certain vendor. There are many factors involved. in why this is. The first is the...

April 3, 2020 by j2sw Cisco Gear Networking news