(TIL) Today I Learned...

Started by Seittit, January 13, 2015, 03:50:21 AM

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LynK

#15
January 21, 2015, 03:52:22 PM
TIL - my new ASAx config suffers from the any4 bug....


TILx2 - Polycom phones will work with cisco auto qos:
Code Select
auto qos voip device cisco-phone
Sys Admin: "You have a stuck route"
            Me: "You have an incorrect Default Gateway"

Seittit

#16
January 21, 2015, 04:07:22 PM
Quote from: LynK on January 21, 2015, 03:52:22 PM
TILx2 - Polycom phones will work with cisco auto qos:
Code Select
auto qos voip device cisco-phone

That makes sense, as the auto qos macro does the following switchport configurations:

Code Select
If QoS was not already enabled, enables QoS globally.

•If VLAN-based QoS was configured for the port, reverts to the default port-based QoS (done for all ports on switching modules with 1p1q0t/1p3q1t ports).

•If the port is configured with the switchport command, sets the port trust state to trust CoS.

•If the port is not configured with the switchport command, sets the port trust state to trust DSCP.

•Creates and applies a trust-CoS or trust-DSCP QoS policy to ports on switching modules with non-Gigabit Ethernet 1q4t/2q2t ports, which do not support port trust.

I'm not a voice guy (thankfully), but I believe the only layer 2 Cisco-proprietary protocol used in VoIP phone configuration is CDP. Since the macro doesn't enable/disable CDP it should work on any device (even a desktop). I say that, but it may be different between Catalyst switches.

icecream-guy

#17
January 22, 2015, 07:28:11 AM
Today I learned what Entropy Labels are...*<|:-{)}
:professorcat:

My Moral Fibers have been cut.

Seittit

#18
January 22, 2015, 07:49:37 AM
Today I learned how to build an OTV domain. Really awesome stuff, will enable our business to have an disaster recovery solution in the event of another hurricane.

mynd

#19
January 22, 2015, 10:02:02 AM
Today I learned, PSTN supports a QoS equivalent

QuoteGETS (Government Emergency Telecommunications Services) is used by government and other designated personnel during crises or emergencies to provide priority processing for local and long distance calls on the public switched telephone network.

deanwebb

#20
January 22, 2015, 02:02:43 PM
Today I learned that there are some features on Cisco gear that consider all addresses to be classful, even if you've got them subnetted.

Plays hell with our network if you consider it to be one big 10.0.0.0/8...
Take a baseball bat and trash all the routers, shout out "IT'S A NETWORK PROBLEM NOW, SUCKERS!" and then peel out of the parking lot in your Ferrari.
"The world could perish if people only worked on things that were easy to handle." -- Vladimir Savchenko
Вопросы есть? Вопросов нет! | BCEB: Belkin Certified Expert Baffler | "Plan B is Plan A with an element of panic." -- John Clarke
Accounting is architecture, remember that!
Air gaps are high-latency Internet connections.

LynK

#21
January 22, 2015, 02:28:11 PM
Quote from: mynd on January 22, 2015, 10:02:02 AM
Today I learned, PSTN supports a QoS equivalent

QuoteGETS (Government Emergency Telecommunications Services) is used by government and other designated personnel during crises or emergencies to provide priority processing for local and long distance calls on the public switched telephone network.


you see this in hospitals too. pretty neat eh?
Sys Admin: "You have a stuck route"
            Me: "You have an incorrect Default Gateway"

LynK

#22
January 22, 2015, 02:29:13 PM
Today I learned that the new cisco 4K branch routers are equal to/less than the G2 ISRs, and they have almost a 10 year life span.
Sys Admin: "You have a stuck route"
            Me: "You have an incorrect Default Gateway"

config t

#23
January 22, 2015, 08:01:05 PM
TIL..

This job gives me a natural high.

I had this wonky issue where a phone was pulling an IP but it wouldn't register in call manager. After some troubleshooting I discovered the SVI wouldn't route off site so I looked in the distro and found a duplicate route.

Lesson learned here.. even if it doesn't first appear like it's a routing issue. It might still be a routing issue. Check. Everything.
:matrix:

Please don't mistake my experience for intelligence.

wintermute000

#24
January 22, 2015, 09:14:18 PM
that a 1% packet loss rate on a 600ms link = 190kb/s maximum individual TCP connection speed due to the laws of physics (without optimisations/WAN acceleration of course)

sgtcasey

#25
January 23, 2015, 12:19:45 AM
TIL I learned to not add an EIGRP summary command to the distribution to router link when there is already one on the router to WAN link.
Taking the sh out of IT since 2005!

deanwebb

#26
January 23, 2015, 09:46:12 AM
TIL that TFTP still works.

I feel dirty for doing it, but it still works when FTP is failing for whatever reason it's failing for.
Take a baseball bat and trash all the routers, shout out "IT'S A NETWORK PROBLEM NOW, SUCKERS!" and then peel out of the parking lot in your Ferrari.
"The world could perish if people only worked on things that were easy to handle." -- Vladimir Savchenko
Вопросы есть? Вопросов нет! | BCEB: Belkin Certified Expert Baffler | "Plan B is Plan A with an element of panic." -- John Clarke
Accounting is architecture, remember that!
Air gaps are high-latency Internet connections.

Seittit

#27
January 23, 2015, 08:05:37 PM
show parser macro

details all macro commands sent

deanwebb

#28
January 23, 2015, 08:55:10 PM
TIL how to make a Hitler Rants video... made two related to networking...

https://www.youtube.com/watch?v=YimI1j9BnKU - data center security breach
https://www.youtube.com/watch?v=xodb32luSM0 - problem with the NAC project.
Take a baseball bat and trash all the routers, shout out "IT'S A NETWORK PROBLEM NOW, SUCKERS!" and then peel out of the parking lot in your Ferrari.
"The world could perish if people only worked on things that were easy to handle." -- Vladimir Savchenko
Вопросы есть? Вопросов нет! | BCEB: Belkin Certified Expert Baffler | "Plan B is Plan A with an element of panic." -- John Clarke
Accounting is architecture, remember that!
Air gaps are high-latency Internet connections.

hizzo3

#29
January 26, 2015, 12:13:25 PM
TIL, don't use anything not brand name, made in China on a box you care about.

My Xen box caught fire over the weekend... Quite literally. I was using one of those made in China Molex to SATA power adapters, and this weekend it decided to short. Luckily I was using a name brand PS that cut the power, which killed the flame. I haven't gone through for damage control yet, but likely I just lost the DVD drive.
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