Some quick template-style notes on deploying clustered ASAs running multiple context mode with transparent contexts. There are some well-documented guides and a few blog posts out there already detailing clustering and transparent-mode firewalls. The purpose of this post is just to dive in to configuration. You may run into some caveats depending on which feature you want to run simultaneously, please refer to the ASA General Operations CLI guide for particulars before deploying clustering. (more…)
BDF is listed in the CCIE Data Center Lab Blueprint as, “1.2.c – Implement BFD for dynamic routing protocols”. In this blog post, I’ll be explaining BFD and going over it’s relevance for dynamic routing protocols. Without further ado.
Bidirectional Forwarding Detection (BFD) is a protocol designed to quickly detect failures in the forwarding-path, and notify the configured protocols (OSPF, EIGRP, BGP, HSRP, etc) immediately, before they’ve even had an opportunity to be aware of the failure themselves. This results in expedited, sub-second detection of failed forwarding-paths, leading to quicker convergence. (more…)
This post is a part of my CCIE:DC studies, but will be useful for anyone needing to quickly configure NetFlow in NXOS. For CCIE:DC purposes, an understanding of how NetFlow is configured in NXOS cannot hurt, especially since it is mentioned in the blueprint (1.5.b – Implement Netflow). (more…)
If you’re in a company that uses Nexus 5Ks to run both LAN and SAN, and for some strange reason your SAN Administrator wants access to the 5Ks for zoning, just deny it. Okay, okay, I guess that won’t fly, so let’s configure role-based access control (RBAC) to lock down what the SAN Administrator has access to.
Good thing about Nexus 5K is there is a built-in role called san-admin that we can use for this purpose. Let’s take a look at the role privileges:
My colleague at (ccie-or-null.net) and I recently came across a design limitation, or “opportunity,” with OTV and firewalls. The plan was to take a current environment with Layer 3 gateways on a firewall, and OTV those networks across multiple Data Center. A simplified topology would look like this: (more…)
My favorite command in all of NX-OS – no feature vpc
Kidding! It’s actually not that bad once you’re aware of how it works, what are the caveats, and how to troubleshoot if you run into an issue. There are an incredible amount of excellent vPC guides out there that I highly recommend you read, such as the vPC Best Practices Design Guide on Cisco.com. Below are some of my notes on setting vPC up in preparation for my next lab study – OTV (hint hint). I’m assuming you have already read the configuration guides and have a general understanding of vPC. (more…)
Nexus 7000 has it’s system jumbo mtu set to 9216 by default. Even though system MTU is set, notice the interface MTU:
N7K-1# sh run all | i mtu system jumbomtu 9216 N7K-1# sh int e3/7 | i MTU MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec