There are always limitations and system-reserved resources on network platforms. For years, certain VLANs have been “off-limits” on IOS platforms. With NX-OS, we also have “off-limit” VLANs, however they are different from the IOS counterparts.
VLANs in IOS and NX-OS
March 30th, 2010Upgrading a Juniper J4350 to 2GB Compact Flash
March 29th, 2010This is somewhat of an impossibility, right? Well, not really. Although not technically supported by Juniper, we are able to go above the recommended 1GB Compact Flash size on J-series routers (at least J4350s).
This was performed on lab equipment, not production equipment. I wouldn’t advise doing anything that would violate any manufacturer’s support agreement on production equipment. Use this at your own risk – your mileage may vary, especially as it’s not following Juniper’s recommendations. Phew – disclaimer finished – now let’s move on…
Nexus (NX-OS) protocol support (and cleanup)
March 29th, 2010Over the years, Cisco has been very instrumental in the design and standardization of many networking protocols. There are lots of examples where a need for a protocol was identified and Cisco filled the need with a Cisco-proprietary protocol. Cisco-proprietary can sound bad, but it really isn’t. Let’s give them some credit here – network equipment vendors are in competition and don’t typically play well together. Often times vendors pitch proprietary solutions in an attempt to carve out a niche that delineates them from their competitors.
There are several standards organizations in existence today (IEEE, IETF, CableLabs, etc.) which many vendors work with and closely follow. While this sounds ideal (and is very beneficial), standards often take a significant amount of time to be ratified, leaving any current needs unaddressed from a standards perspective. The only alternative (for a quick resolution) is a proprietary solution, while the standards process is given time to complete. Read the rest of this entry »
Missing VLANs are not automatically created in NX-OS
February 17th, 2010In IOS, if we assign a switchport to a non-existent VLAN, the switch will kindly create the missing VLAN for us. NX-OS does not do that – if a switchport is assigned to a missing VLAN, the interface will be placed in the down state. Let’s look at it… Read the rest of this entry »
FEX configs are retained
February 15th, 2010The N5k maintains the config of the FEXs, even when they’re removed (and even though it’s not visible to us). In this article, we’re going to look into this a little further… We’ll start with a working FEX, using Po100 (with Eth1/19-20 being the physical bundle members). Read the rest of this entry »
Some NX-OS features can’t be manually enabled
February 10th, 2010The whole idea around features in NX-OS has been intriguing to me. It’s a good idea – I like it. It seems very similar to services on many other OSs (particularly *nix systems), however it doesn’t always strike me as having a rich feature set as of now.
For instance, the NX-OS config guides repeatedly refer to the show feature command to look at which features are enabled. I’ve already mentioned that this command doesn’t exist today in older NX-OS versions – the currently-available NX-OS versions today support this feature (a reader confirmed this on the N7k and I’ve confirmed it on the N5k). See this article for more info. There are some interesting behaviors around features, in that some are manually enabled, while others are automatically enabled and disabled as needed. Let’s dig into this a little deeper for an example… Read the rest of this entry »
EtherChannel behavior in NX-OS
February 9th, 2010I’ve had a lot of discussions with clients about the behavior of Port-Channel interfaces and their associated physical counterparts. It’s necessary for many parameters of the physical and logical interfaces to be the same. Here’s the behavior within NX-OS and the preferred way that I make changes to EtherChannels.
In this, we’re going to continue working with the logical interface Po100 and the physical interfaces Eth1/19 and Eth1/20 which will be in the EtherChannel. Read the rest of this entry »
Why EtherChannels should be used for FEX interfaces
February 8th, 2010I prefer to use port-channel interfaces for the fabric interfaces when connecting fabric extenders (FEXs). If a single interface in the bundle fails, it won’t remove the fabric extender interface – it simply reduces it’s bandwidth. This results in stable, predictable, redundant and resilient behavior. Let’s prove this point. Read the rest of this entry »
Cisco WAAS – weird error when trying to register WAEs to the central manager
February 5th, 2010When working on a WAE 500 (I know, this is really old hardware), I ran into an issue when trying to register with the central manager (CM):
waas-edge#sh cms info Device registration information : Device Id = 216 Device registered as = WAAS Application Engine Current WAAS Central Manager = 10.1.1.200 Registered with WAAS Central Manager = 10.1.1.3 Status = Pending(CM is busy, retry later) Time of last config-sync = Fri Feb 5 09:20:12 2010 CMS services information : Service cms_ce is running waas-edge#
Here’s how I resolved it! Read the rest of this entry »
Experimenting with Static Pinning
February 4th, 2010What happens when more links are associated with an FEX than are permitted in the max-links parameter? Let’s find out…
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