Saw this modular data centre rolling down the highway today.
HP Networking has announced no more software licenses on their networking kit.
A short summary of the Fibre Cable Connectors, description and some notes on usage. This is summary notes and intended for reference.
When you first receive a router from a Cisco warehouse, it comes with a complete collection of IOS add ons. A common question is whether these files are used for anything ?
Why does a Cisco IOS SX switch not let you use VLANs 1002 − 1005 ?
Found this in the Cisco IOS 15.1M manuals today
IP Routing: EIGRP Configuration Guide, Cisco IOS Release 15.1M&T
The goodbye message is a feature designed to improve EIGRP network convergence. The goodbye message is broadcast when an EIGRP routing process is shut down to inform adjacent peers about the impending topology change. This feature allows supporting EIGRP peers to synchronize and recalculate neighbor relationships more efficiently than would occur if the peers discovered the topology change after the hold timer expired.
Once upon a time the command was “show ip eigrp topology” to show EIGRP topology, now it’s “show ip eigrp topology all” and the old command show only Feasible Successors.
I stumbled across an old diagram I made a long time ago about the direction of flows on a BlueCoat PacketShaper. Since I’ve been looking for it for about three years, I’ve diagrammed it quickly so that it is here for future reference when I’m working PacketWise in the future. PacketShaper PacketWise is one of my very favourite tools for managing traffic flows, and much preferable to PHB QoS aka DiffServ for many types of use cases.
An TCP flow has four possible directional attribute related to the use of a inside and outside networks, and whether the flow was initiated from the client to server which sets the “direction” of the flow relative to the Packeteer. The flow is determined by who initiated the three way handshake. For purposes here, the Client always initiates the TCP connection, and the Server terminates the connection.
TCP Session and Direction
Most people understand the three way handshake, but not many consider the direction of the session.
The connection from the client to the server is outbound, but is inbound on the server. And vice versa, the server outbound session is inbound on the client.
That’s not very useful for being able to define the direction of flows.
Why is direction important ?
For an FTP upload server, you might have the reverse condition where the inbound traffic is far more than the outbound.
To make the most of your Internet connection for this case, you could configure the inbound bandwidth on your Internet connection to be 80% FTP, 20% HTTP and the outbound bandwidth to be 20% FTP and 80% HTTP. This gives a far better utilisation, especially in regards to better TCP Windowing and overall TCP goodput.
I found this on Cyber Corner blog:
Another missing ASA-feature: telnet and ssh client: ” Every single decent Cisco-device on earth has the ability to make an CLI-user jump to another device with telnet or ssh. Except the ASA. I really wish that this feature could be added. Right now I am troubleshooting a firewall and from where I am right now the only way in is to SSH to the ASA. I can do whatever I want inside the firewall from my SSH-window, but I need to access a router inside of that firewall, and if this feature wasn´t missing i could simply run ‘ssh ip-address’ to jump to the switch´s CLI.
Am I the last CLI-.guy on this planet? Please, Cisco?
A lot of people regard Virtual Trunking Protocol(VTP) as nothing but trouble. Indeed, it’s hard to find many people who will implement it on their network. I find this baffling – it’s a great tool that dramatically reduces time, errors, and troubleshooting is something that we should all embrace and use wherever we can. Naturally, with great power comes great evil. So, lets be clever instead.