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Aug 19 / thebrotherswisp

TheBrothersWISP 52 – Ubiquiti UCRM vs Aircontrol, BGP to Customers, 100Gb Switch



Greg and Mike go down the tangent hole, and have a good time doing it.

This cast we talk about:
Ubiquti Front Row
Ubiquiti UCRM
Bridgewave has 10Gb AES 256 80ghz link
BGP for redundant customer connections
WISPAPALOOZA Calendar
Midwest IX is looking for a sales leader
Dragonwave Bankruptcy
100G switches
Unimus Beta licenses expiring

Keep contacting us: contactus (at) thebrotherswisp.com or https://facebook.com/thebrotherswisp

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Aug 15 / Greg

Using Cisco EEM To Flap Interfaces For BGP Convergence

I like many people often balance price with need. It’s often difficult to look into my crystal ball and determine what piece of gear I need at a site…do I need an expensive router(both in cost and power) or can I get away with a switch…?

In some scenarios I will use a layer 2 point-to-point(transport) to connect to a remote location. At that site I might connect to one more more BGP peers. If I can just use a switch at that site it can save me a lot of money since I don’t have to put a big beefy router out at the site.

This puts me in a delicate position sometimes. When connecting to BGP peers they will default to sending hello messages every 60 seconds. If they miss three hellos, the peer is considered down and all routes from them are flushed. If these peers are directly connected this usually isn’t an issue since an interface flap will immediately flush all peer learned routes. What if, for example, you are using a switch to connect the peers together. If the transport link goes down, the peer connected to that switch has no idea…so that peer will continue to announce your routes for up to 3 minutes by default, blackholing all of that traffic! While it’s true that you should be able to lower these hello times, some of my peers won’t allow that…what to do…?

If only I could flap the peer interfaces when my transport drops…well, with Cisco Embedded Event Manager, you can.

First, configure tracking of an interface. This will allow the switch to watch the interface, and when it goes up or down, log it:

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!Here I'm tracking Gigabit 1/17 on the switch
track 1 interface Gi1/17 line-protocol
!I configure it here to wait 5 seconds before alerting that the interface has returned.  This can easily be extended.
 delay up 5

The delay command can also have a down delay set so that it has to be down X seconds before being declared down. It would be configured as “delay up X down Y”.

Next I create an EEM script that reacts to the syslog messages that are created when the interface goes down:

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event manager applet transit-flap-down
 event syslog pattern "TRACKING-5-STATE: 1 interface Gi1/17 line-protocol Up->Down"
 action 1.0 cli command "enable"
 action 1.5 syslog msg "transport flap down"
 action 2.0 cli command "conf t"
 action 3.0 cli command "interface gi1/2"
 action 4.0 cli command "shutdown"
 action 5.0 syslog msg "shutdown BGP Peer1 gi1/2"
 action 5.1 cli command "end"

Here’s the oposite script that watches for the tranport interface to return, then bring the peer interface back up:

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event manager applet transit-flap-up
 event syslog pattern "TRACKING-5-STATE: 1 interface Gi1/17 line-protocol Down->Up"
 action 1.0 cli command "enable"
 action 1.5 syslog msg "transport flap up"
 action 2.0 cli command "conf t"
 action 3.0 cli command "interface gi1/2"
 action 4.0 cli command "no shutdown"
 action 5.0 syslog msg "enabled BGP Peer1 gi1/2"
 action 5.1 cli command "end"

So in action, the transport interface goes down, and Gi1/2 is shutdown until it returns. This could shutdown multiple peer interfaces if you had multiple peerings off of this switch. EEM is pretty versatile and can be extremely useful.

Well, happy routing folks!

Jul 31 / Greg

The Ataritik – A Mikrotik HapMini In An Atari Cart

We were at the classic gaming fest in Austin a few days ago, and they had bins full of all kinds of retro games. Some of the bins had classic Atari 2600 carts for a buck…and I figured I could find a reason to buy one. After a second or two of noodling I figured a HapMini would likely fit nicely inside…and I was right!

There’s a screw hiding under the labels. I used a heat gun to peel it off.

Looks like it will fit…

Not really much to it

The HapMinis open up quite easily.

The supports I nipped of with some pliers so the board would sit flatish

Dry fit looks good.

I 3d printed a face plate just to clean up the look a bit.

I brushed it with acetone to strengthen the part.

I used puffy double stick tape to lock it in place.

Taped in place

Reassembled

I used a little hot glue to attach the face plate to the Mikrotik.

Ahhh, lovely blinking lights.

Boooyaaaaa

Anyone want a Pac-tik?

This was a fun quick/dirty mod that is going to be a lot of fun keeping in my laptop bag. I think it will get some fairly positive reactions when I pull it out to fix a network or demonstrate an idea. This is one of those “stop and smell the roses” projects I never take time to do anymore. Hopefully I’ll be getting my hands dirty some more soon. Have fun and happy routing 🙂

Jul 31 / thebrotherswisp

TheBrothersWISP Special – New MT Chips and Bridging / wireless and UI design



This is a special cast with Thrift dropping some knowledge bombs on: Wilson, Mike, and Tomas.

This cast we talk about:
New chips Mikrotik is using in the CRS3xx line.
In particular, these two: CRS317 and CRS326
Here’s a bit of information on what Marvell’s eBridge functionality means
Here’s a bit on Carrier Ethernet
Mikrotik’s bridge hardware offloading
NV2 AP Sync

Keep contacting us: contactus (at) thebrotherswisp.com or https://facebook.com/thebrotherswisp

Here’s the video:(if you don’t see it, hit refresh)

Jul 23 / thebrotherswisp

TheBrothersWISP 51 – UBNT Signed Firmware, New FCC Spectrum, VMware Vs Native VLAN



We have the lovely Greg, the sleepy Tomas, and the sassy Mike. We talk the talk, though it’s too hot for anyone to walk the walk.

This cast we talk about:
RF elements link calculator for horns
Ubiquiti blocking cambium elevate code
Native VTLAN on a trunked port doesn’t seem to work on VMWare
Mike bitches about people in FB groups LOL
MM using 40km SM optics and modeconditioning patch cables was a bust – try 2km 100mb optics
LTE Questions
MT hardware offload bridging released, then pulled
FCC Net Neutrality (brief)
FCC 3550 – 3700 (brief)
FCC 3700 – 4200 (brief)
bob and chuck
Unimus 1.0

Keep contacting us: contactus (at) thebrotherswisp.com or https://facebook.com/thebrotherswisp

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Jul 10 / thebrotherswisp

TheBrothersWISP 50 – Elevate On Mikrotik, New Mikrotik Bridging, iBGP Full Mesh Or Nah



It’s Greg, Tomas(of course), and Miller catching up on a few network related thing-o’s.

This cast we talk about:
UBNT switch through the FCC, has built in wireless
UBNT ONT NanoG
Note – Cambium ePMP exploit out/update fools
Mike and company do a DNS video
Cambium Elevate on MikroTik
MikroTik new bridging in 6.40rc
ShouldIBlockICMP – NO

Keep contacting us: contactus (at) thebrotherswisp.com or https://facebook.com/thebrotherswisp

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Jun 25 / thebrotherswisp

TheBrothersWISP 49 – Mesh Networking, Get Started In Automation, Customer Service



Greg grills the Slovakian Robot(Tomas) on some random things.

This cast we talk about:
Some automation getting started tips(plink, expect scripts, ansible)
Success stories from Unimus thus far
Speed and quality of services to customers
PPPoE VPN issues Tomas worked out
Favorite thing you are watching on TV right now

Keep contacting us: contactus (at) thebrotherswisp.com or https://facebook.com/thebrotherswisp

Keep contacting us: contactus (at) thebrotherswisp.com or https://facebook.com/thebrotherswisp

Click the link below to view the article!