Computer Switch

I like computers.

My career was in computers.  My Applied Math degree from UC Berkeley was  fun to obtain, but it's not an obviously degree that leads to a job.  But the computer skills I used while getting my degree were.

In our home we have a lot of things that connect to the network/internet.   We recently switched to a cellular internet modem solution, which also provides a wireless access point (in both 2 and 5G), but has only two ethernet ports.  I had a ten-port switch attached, but that was too few, so I daisy-chained another ten-port switch.  That ran out of ports when we added solar to the house.

I started looking for a 20-port switch that would help, but found instead a 24-port switch that also supports Power-Over-Ethernet: a Juniper EX2200-24P-4G 24 Port PoE Gigabit Switch.  It was quite affordable on ebay, so I bought it.

Well, during the last part of my work career, two of my co-workers were Network Administrators who dealt with switches like this.  I now have a MUCH greater appreciation for what they did.

Connecting the Switch to my Laptop

When the switch arrived, I plugged it in and hooked up the cellular router and a couple ethernet cables connected to some devices.  Alas.   They didn't connect.  Back to ebay to order a RJ45-to-USB RS232 converter cable, so I could have my laptop talk to my new Juniper switch.

When it arrived and I plugged it in (to the console port on the back, not the ge 0/0/0 port on the front), HURRAH!   Text. But alas.  The switch had not been reset to factory settings, and expected me to know the old root password for whoever owned it before.  Back to the internet.

Resetting the Root Password

With a little search engine investigation, I found a lovely article (Reset root password EX2000 Juniper switch) that described resetting the root password (if you don't know it) using the old Reboot/Spacebar/boot-s trick!  I did that and wella!  I had the root password reset to something known.

Reset Switch to Factory Default Settings

Since I did not know what the switch had been set up as, the next step was to reset it to the factory defaults.  Since I now knew the root password, I could log in.  A little search engine investigation led to an article (Step By Step Factory Reset Wipe a Juniper EX Switch).  You just have to do the old  request system zeroize trick.

Initialization Setup

Now that my fancy 24-port switch was back to factory default, I could turn it from a super fancy Level-3 POE prioritization capable switch to a dumb stupid 24 port do-nothing switch.  I started with the old ezsetup trick.  I had to do some guessing about the Default IP Gateway, but got it right even though I'm not a Network Administrator.  I rebooted the switch.

Warning Alarms

And of course, the warning alarm LED came on.  But I was expecting it, based on my research.  The switch expects to have a computer plugged into the Management port in the back, and will complain if it doesn't.  A little search engine investigation found an article (How to turn off the alarm LED on Juniper Switches).  To have the switch ignore the lack of a Management Computer, you use the old set chassis alarm management-ethernet link-down ignore trick.  I was also getting a "Host 0 Boot from backup root" alarm, This article (Switch boots from backup root partition) introduced me to the old request system snapshot media internal slice alternate trick.

Almost there

Everything was plugged in and working fine.  Almost.

Lynn asked me to play some music on Sunday.  I fired up my Samsung smart-ish TV and looked for the Diskstation entry (which normally appears because my Synology NAS is acting as a DLNA-compliant media server).  It wasn't there.  I had to use Plex and navigate to my music folders to play her tunes.  So not everything was right.  Plus, when I browsed to the Cellular Router to check the devices, while it DID have the right summary count of both wired and wireless devices, when I asked to see the list, there were none.  Strange.

A little search Engine investigation led me to this lovely article (Multicast Problems on the Juniper EX Series) , which explains that "IGMP Snooping is enabled by default".  Well, everyone that's anyone knows that IGMP shouldn't always not be disabled.  Or something.  As the author clearly explains:

Since IGMP snooping is enabled and there are no IGMP join requests, the EX doesn’t bother forwarding the multicast to any ports because it believes nobody wants to receive it. Not so, Juniper!

Using the old delete protocols igmp-snooping trick, I then fired up the TV and there was the Diskstation.  PLUSSING, this seemed to also solve the strange No-Devices problem.

So for $45 and a bit of search investigation, I now have 24 ports, any of which could be POE enabled.