Register a SA Forums Account here!
JOINING THE SA FORUMS WILL REMOVE THIS BIG AD, THE ANNOYING UNDERLINED ADS, AND STUPID INTERSTITIAL ADS!!!

You can: log in, read the tech support FAQ, or request your lost password. This dumb message (and those ads) will appear on every screen until you register! Get rid of this crap by registering your own SA Forums Account and joining roughly 150,000 Goons, for the one-time price of $9.95! We charge money because it costs us $3,400 per month for bandwidth bills alone, and since we don't believe in shoving popup ads to our registered users, we try to make the money back through forum registrations.
«387 »
  • Post
  • Reply
Sepist
Dec 25, 2005

FUCK BITCHES, ROUTE PACKETS


Gravy Boat 2k

Is all the traffic on one vlan? If it's spread around you can split the spanning-tree priorities upstream so that one uplink switch is the root for half the VLANs and the other switch the other half.

This is taking a lot of assumptions though. There are other things to consider like downstream traffic & routing

Adbot
ADBOT LOVES YOU

tortilla_chip
Jun 13, 2007


MC-LAG or stop running a single topology spanning tree.

cheese-cube
May 28, 2007

OMNIA SUNT COMMUNIA





mythicknight posted:

I have an access switch stack that has a single link to two different core switches. My problem is it seems to be pushing all traffic up one link right now, and its saturated. Anything I can do to tell it to use both? Port channel wouldnt work I think since each link is going to a different device upstream. Not sure why we didn't run multiple links for each connection but here we are

A lot of the config is over my head, but the interfaces seem to be configured identically. Trunks, vlans, etc.



Maybe escalate to a network person.

mythicknight
Jan 28, 2009


Sepist posted:

Is all the traffic on one vlan? If it's spread around you can split the spanning-tree priorities upstream so that one uplink switch is the root for half the VLANs and the other switch the other half.

This is taking a lot of assumptions though. There are other things to consider like downstream traffic & routing

Mainly on one vlan for this stack. Though this did put me on the path of checking the core switches spanning tree, and they are indeed set to have everything downstream funneled to one, which is then going across to the other core switch to get out the WAN. This seems horribly inefficient to me so I'm probably going to reprioritize the other core just for this floor's stack and see what happens. Either the stack link is the issue and it'll keep happening, or its the cross link upstream and this'll bypass that. Or things will explode.

cheese-cube posted:



Maybe escalate to a network person.

I happily would, but they are all on vacation

It's just me and another guy, and we just do the UC/voip side of things. On one hand, this is a good learning experience. On the other this is terrifying.

Eletriarnation
Apr 6, 2005

People don't appreciate the substance of things...
objects in space.


Pillbug

mythicknight posted:

I have an access switch stack that has a single link to two different core switches. My problem is it seems to be pushing all traffic up one link right now, and its saturated. Anything I can do to tell it to use both? Port channel wouldnt work I think since each link is going to a different device upstream. Not sure why we didn't run multiple links for each connection but here we are

A lot of the config is over my head, but the interfaces seem to be configured identically. Trunks, vlans, etc.

tortilla_chip posted:

MC-LAG or stop running a single topology spanning tree.

Yep, this is a key limitation with STP and traditional L2 switching - redundant links get shut down, not used. If your switch and the two it's uplinking to support multi-channel link aggregation and they are also connected that could be an option, but that's really kind of a redesign. Otherwise you need to do a different redesign to push routing to your access layer and enable L3 ECMP or you need to just run some more links to your core switches.

Methanar
Sep 26, 2013

It always was

Yeah there's no trivial easy way to fix the issue as described.

Best you can do is make the one saturated link bigger with a port channel.


The other options are multiple spanning tree or using L3.

Thanks Ants
May 21, 2004

Bless You Ants, Blants



Fun Shoe

If you arenít comfortable with what youíre doing then do not gently caress with spanning tree settings, especially on a Friday.

CrazyLittle
Sep 11, 2001







Clapping Larry

Thanks Ants posted:

If you arenít comfortable with what youíre doing then do not gently caress with spanning tree settings, especially on a Friday.

... Unless you enjoy working on Saturday.

cheese-cube
May 28, 2007

OMNIA SUNT COMMUNIA





CrazyLittle posted:

... Unless you enjoy working on Saturday.

And get paid overtime...

mythicknight
Jan 28, 2009


Yeah, after talking with our (IT) management we're just gonna leave it alone for now and wait out the user complaints till the whole team is here to take a look at it.

If it gets to the point that someone wants something done now, we'll try reprioritizing that vlan to use the other core and see what happens.

Longer term fix is adding more links going up to each core. Read a bit about MCLAG and it sounds nice, and might work on the equipment there. We already do it at another site with vPCs, so why we dont do it at the affected site is...

Heres a horrible phone drawing to make more sense of it. Thanks for the tips all.

Thanks Ants
May 21, 2004

Bless You Ants, Blants



Fun Shoe

Are C1 and C2 stacked or linked in some other way that makes them a virtual chassis or similar?

mythicknight
Jan 28, 2009


Just a port channel between those boxes currently.

Ahdinko
Oct 27, 2007

WHAT A LOVELY DAY


What model switches are at your core? That will answer if you can do vPC/MC-LAG at all.
Otherwise if the upstream links from the stack is your point of contention, the easy option is to stick a second cable in between C1 and the stack and then port channel it. Changing your root bridge wouldn't help if that's the problem.

If you don't have the extra cabling because its far away and uses fiber or whatever, you could steal the cable going to the other core. Its a lovely non redundant design but if it saves you a week or two of big production issues then it may be worth doing.

Ahdinko fucked around with this message at Jun 1, 2018 around 22:08

Partycat
Oct 25, 2004

Rule Number Dos:
A lot of you maggot people are gonna see some things that you're not used to seein'. I'm talking about nudies! That's right! Botticelli may show a titty or two and Michelangelo may show a mans willy dong long prong... but you are not, I repeat, you are not to titter !

Plaster Town Cop

Port channels do not load balance traffic - it is selected per an algorithm with on a lot of equipment isnít adjustable . In some cases you can add 7 more cables and accomplish nothing .

abigserve
Sep 13, 2009

this is a better avatar than what I had before


mythicknight posted:

I have an access switch stack that has a single link to two different core switches. My problem is it seems to be pushing all traffic up one link right now, and its saturated. Anything I can do to tell it to use both? Port channel wouldnt work I think since each link is going to a different device upstream. Not sure why we didn't run multiple links for each connection but here we are

A lot of the config is over my head, but the interfaces seem to be configured identically. Trunks, vlans, etc.

As mentioned spanning-tree will be blocking one of the links and there isn't anything (practical) you can do about it. The least disruptive option is to convert each link into a portchannel (so one portchannel per switch) then add additional links as required. You'll still end up only using 50% of the capacity but at least it'll be 50% of a much bigger number.

Ahdinko
Oct 27, 2007

WHAT A LOVELY DAY


Partycat posted:

Port channels do not load balance traffic - it is selected per an algorithm with on a lot of equipment isnít adjustable . In some cases you can add 7 more cables and accomplish nothing .

Even src-mac load balancing will help unless all the traffic on their access stack is from a single host. Plus i think 95% of cisco switches you can buy in the last 8+ years have adjustable load balancing

Ahdinko fucked around with this message at Jun 2, 2018 around 10:53

TooLShack
Jun 3, 2001

SMILE, BIRTHDAY BOY!

I'm load balancing across 3 different PTP radios, but like Ahdinko said if it's different connections it will load them across the port channel. It's really awesome for my needs since the radio I use can drop due to rain fade and interference, so I have redundancy and load balancing.

Partycat
Oct 25, 2004

Rule Number Dos:
A lot of you maggot people are gonna see some things that you're not used to seein'. I'm talking about nudies! That's right! Botticelli may show a titty or two and Michelangelo may show a mans willy dong long prong... but you are not, I repeat, you are not to titter !

Plaster Town Cop

Ahdinko posted:

Even src-mac load balancing will help unless all the traffic on their access stack is from a single host. Plus i think 95% of cisco switches you can buy in the last 8+ years have adjustable load balancing

Yeah maybe if itís all Cisco IOS. And yeah in my experience in typical LAN access, 95% of traffic is host -> router and sticks to one link , which implies that itís not src max out of the box

cheese-cube
May 28, 2007

OMNIA SUNT COMMUNIA





cheese-cube posted:



Maybe escalate to a network person.

tadashi
Feb 20, 2006



It's too bad this thread lends itself to a short title because this is my favorite Cisco "bug" I've discovered recently.


https://quickview.cloudapps.cisco.c.../bug/CSCuu29995

quote:

However there is no Cisco Documentation stating this and so customers have a concern that this cannot be explained during security audits. Hence filing this Documentation defect to document this.

I've certainly seen plenty of undocumented stuff but this is the first time I've seen documentation of a lack of documentation of an issue.

tadashi fucked around with this message at Jun 5, 2018 around 13:41

Eletriarnation
Apr 6, 2005

People don't appreciate the substance of things...
objects in space.


Pillbug

When I worked in TAC, my favorite bugs to file were doc bugs. "Hey, document A says this is supported in version X and document B says it's supported in version Y and document C says it doesn't work at all. Figure out which is right and correct the other two."

Less fun was when the technical writer would come to me as a TAC engineer and ask me which one is correct. "I don't know, I was trying to find that answer when I crawled down this rabbit hole. Go find the developer who wrote it and ask him."

GreenNight
Feb 19, 2006
Turning the light on the darkest places, you and I know we got to face this now. We got to face this now.

That developer in India no longer exists.

Eletriarnation
Apr 6, 2005

People don't appreciate the substance of things...
objects in space.


Pillbug

Never had that happen with an documentation bug, but it did happen for an actual bug once - it was for a relatively niche product and the whole team had been reassigned after it didn't take off, so the only person we could find connected to it was the director. He started out acting like he couldn't help us but once we said "look, the buck stops with Engineering - we will give the case to you if you can't find someone to help with it" we got what we needed.

Kazinsal
Dec 13, 2011



GreenNight posted:

That developer in India no longer exists.

"What, we fired him?"
"No, he's just gone. Vanished off this plane to go to the great business unit in the sky."

Prescription Combs
Apr 20, 2005
   6

quote:

ERROR: Long VLAN name knob is not enabled, vlan-name >32 char is not allowed.

Had a laugh at this one.

Partycat
Oct 25, 2004

Rule Number Dos:
A lot of you maggot people are gonna see some things that you're not used to seein'. I'm talking about nudies! That's right! Botticelli may show a titty or two and Michelangelo may show a mans willy dong long prong... but you are not, I repeat, you are not to titter !

Plaster Town Cop

Look at the deferral notice for the half dozen recent issues of CE software for the telepresence endpoints.

Someone put a Star Wars joke in it where a robot shows up and it says ďMay the FourthĒ .

That someone is probably now relatively fired.

Oops.

ragzilla
Sep 9, 2005
don't ask me, i only work here




Anyone else going to Live next week?

Sepist
Dec 25, 2005

FUCK BITCHES, ROUTE PACKETS


Gravy Boat 2k

I'm skipping live this year, probably won't go until Vegas again

FatCow
Apr 22, 2002
I MAP THE FUCK OUT OF PEOPLE


Nope, holding out for Orlando.

edit:
Oops, this was Orlando. Guess I should have got on that.

FatCow fucked around with this message at Jun 11, 2018 around 01:23

Kazinsal
Dec 13, 2011



Sepist posted:

I'm skipping live this year, probably won't go until Vegas again

Same here.

GreenNight
Feb 19, 2006
Turning the light on the darkest places, you and I know we got to face this now. We got to face this now.

Those free Meraki MS220-8P switches you get from watching a webinar, how much is the license after 3 years?

Thanks Ants
May 21, 2004

Bless You Ants, Blants



Fun Shoe

https://www.cdw.com/product/Cisco-M...-switch/3067946

GreenNight
Feb 19, 2006
Turning the light on the darkest places, you and I know we got to face this now. We got to face this now.

Thanks. Not completely terrible but eh.

less than three
Aug 9, 2007

Fire Sights and LED Lights

ESC 2010 Never Forget

Fallen Rib

The 3 year is $100 which was low enough to not with replacing it.

https://m.cdw.com/product/Cisco-Mer...-switch/3059936

Adbot
ADBOT LOVES YOU

ate shit on live tv
Feb 15, 2004

LBGT United
Did nothing wrong.

Anyone else have fun with the massive fiber cut in the Secaucus, NJ area yesterday morning? Something like 2000+ fibers had to be respliced, work still ongoing.

  • 1
  • 2
  • 3
  • 4
  • 5
  • Post
  • Reply
«387 »