I often get a question how to protect IKE negotiation from being abused, overused or simply attacked. Here are some thoughts about it: IKEv1 is...

Recently, I've been asked by a customer for configuration of VRF aware IPSec. This particular case required Site-to-Site IPSec VPN where one Spoke has...

Unfortunately, no many people know about this great product that can be used in both lab environment and production for enterprise access scenarios and...

Cisco Services Router 1000V is a virtual router provided by Cisco that can run on VMware and it's perfect for everybody to check new...

Secure MAC Addresses You can configure these types of secure MAC addresses: Static secure MAC addresses - These are manually configured by using the switchport port-security...

Objective This tech note outlines the main differences in interface support between Cisco® NX-OS Software and Cisco IOS® Software. Sample configurations are included for Cisco...

Objective This tech note outlines the main differences in Hot Standby Routing Protocol (HSRP) (IPv4) support between Cisco® NX-OS Software and Cisco IOS® Software. Sample...

Objective This tech note outlines the main differences in Enhanced Interior Gateway Protocol (EIGRP) support between Cisco® NX-OS Software and Cisco IOS® Software. Sample configurations...

Some people keep asking me about CCDE exam, how it looks like, how to prepare and most importantly how to pass it. Here I'd...

Overview For additional information regarding Overlay Transport Virtualization (OTV) on Cisco NX-OS devices, refer to the overview chapter available in the Cisco Nexus 7000 Series...

Many people keep asking me about Internet Edge for their Enterprise network: how to build it, what is currently in use, what are trends,...

Topology Configuration Configuration of the Headend Router (PE5): Example In the following example configuration of the headend router, note the following: IPv4 multicast routing is enabled with the...

MPLS MTU Values During Upgrade If you have configuration files with MPLS MTU values that are larger than the interface MTU values and...

In a normally routed environment, frames pass from a source to a destination in a hop-by-hop basis. Transit routers evaluate each frame's Layer 3...