Posts Tagged ‘Juniper’

Cumulus attacks on Juniper (again)

Thursday, November 12th, 2015

I have a lot of time for Cumulus Networks – I think they’re doing some very cool and unique things with their Cumulus Linux operating system for switches and they genuinely have something different to offer, but when they publish blog posts like their one today ( I lose a lot of respect for them.

This seems to be nothing more than a thinly veiled attack casting FUD (Fear, Uncertainty and Doubt) at a competitor – a knee-jerk reaction to a threat to their business. It actually reads pretty similarly to their blog post when Juniper originally announced the OCX range ( They’ve probably attacked other vendors in a similar manner.

For example, just by going to the main QFX5200 page on the Juniper web site (, I find:

Open access to the standard Junos Linux kernel, enabled by the disaggregated version of the Junos software, allows users to install third-party Linux RPM packages and create guest containers and VMs with central resource management and programmable APIs.

Yes that still needs a little more detail, but it answers at least some of the questions and all it took was a couple of clicks! Imagine what you could find out by actually speaking to someone familiar with the details…

I have a few questions of my own for Cumulus Networks;

  1. Did Cumulus Networks actually attempt to find out the answers to any of these points yourselves? If so, were you unable to find the details, or did you just not like what you found so decided to feign ignorance?
  2. Will Cumulus Networks put their money where their mouth is and make sure that Cumulus Linux runs on the Juniper QFX5200 series of switches (assuming that Juniper are willing to co-operate)?
  3. Does Cumulus Linux currently run on any switches powered by the Broadcom StrataXGS Tomahawk chipset? It doesn’t seem to be listed anywhere on the Cumulus Linux HCL that you so helpfully linked to from your blog post.
  4. Does Cumulus Linux currently run on any switches which support 25G, 50G or 100G Ethernet ports? These also seem to be conspicuously absent from the Cumulus Linux HCL.
  5. When will Cumulus Networks offer a fully featured MPLS implementation on their Cumulus Linux control plane?

Upgrading to Junos 12.3 from before 10.4R2 on Juniper EX

Monday, October 19th, 2015

In the release notes for Junos 12.3 ( on Juniper EX series switches, it says:

Upgrading from Junos OS Release 10.4R2 or Earlier

To upgrade to Junos OS Release 12.3 from Junos OS Release 10.4R2 or earlier, first upgrade to Junos OS Release 11.4 by following the instructions in the Junos OS Release 11.4 release notes. See Upgrading from Junos OS Release 10.4R2 or Earlier or Upgrading from Junos OS Release 10.4R3 or Later in the Junos OS 11.4 Release Notes .

Unfortunately, Juniper don’t list any Junos releases older than 12.3R1 for the EX4200 (and possibly other EX series) on their download site.

After poking around the Juniper support site for a bit, I found technical bulletin TSB16151 (, which contains downloads for Junos 11.4R8-S1 on EX2200, EX3200, EX3300, EX4200, EX4500, EX6200, EX8200 and XRE-200.

With this and the jloader files from technical bulletin TSB15524 (, I was able to complete the upgrade successfully.

4GB of RAM on a Juniper J-Series router (J6350)

Wednesday, May 2nd, 2012

Officially the Juniper J-series routers such as the J6350 only supports a maximum 2GB of RAM. The J6350 comes with 1GB of RAM installed and if you want to add more then you have to buy your RAM from Juniper at inflated prices, however as the J-series are standard x86 machines with Netburst era Celeron and Pentium 4 processors you can simply install standard DDR400 RAM if you aren’t worried about being covered by JTAC support.

Not only does installing your own RAM save you a shedload of money compared to the Juniper equivalent part (JXX50-MEM-512M-S), but you can also exceed the “supported” 2GB maximum 4x512MB configuration, which provides additional memory to the control plane. The four memory slots present on a J6350 can take a 1GB DIMM each, however thanks to a 32bit architecture and mapping of the PCI bus into the same address space, you can only actually use 3.5GB of that 4GB.

The J-series routers are picky about what RAM they use however, so I like to stick to Crucial sticks; partly as that’s what Juniper use but mostly because I use Crucial elsewhere for their great customer service and a genuinely quality product. If you want to stick with a 2GB maximum then you can use Crucial part number CT2KIT6464Z40B, which provides 2x512MB sticks. Alternatively, Crucial part number CT2KIT12864Z40B provides 2x1GB sticks, allowing you to max the chassis out at 4GB across all four slots.

Once you’ve got all 4GB of memory installed in the chasis, boot the router up and from the JUNOS operational mode CLI issue the command “show chassis routing-engine” – you should see a total of 3584MB of memory split between 3008MB of control plane memory and 576MB of data plane memory. If you only opted for 2GB of memory then the 2048MB total will be split between 1472MB of control plane memory and 576MB of data plane memory.

Remember, you replace the RAM in your routers at your own risk and doing so will likely void your warranty as well as rending your system unspported by JTAC.