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Occasional Contributor
Posts: 5
Registered: ‎10-01-2013
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ISL Trunk between 6510 and 5300 - Brocade Best Practice?

Hello,

im just wondering what is the best practice advised from Brocade to connect the above stated switches?
We want to use a Bandwidth of 4 x 8Gig for ISL's.

My opinion is, that it is better to connect the 6510 with one big ISL-Trunk using Ports 0-3 and terminating at one Portgroup at the 5300 (lets say 0-3 aswell). I know that the 6510 has just 1 ASIC, so it doesn't matter where to connect the ISL's.

A colleague of mine has a differnet opinion.
He is saying: It's better to connect 2 times 2 x 8Gig ISL Trunks on different Portgroups on the 6510 and terminate on different Portgroups on the 5300 aswell. In his opinion, it is better to distribute the ISL-Trunks on differnt Portgroups. Not because the 6510 has just one ASIC but because of the termination on the 5300 on differnt ASIC's. So if one ASIC would die, you still would have at least the 1 ISL-Trunk alive. Same with Portgroups on both Switches, if one Portgroup dies you still would have a second portgroup which is delivering traffic.

I kind of understand his opinion, but the fact that the 6510 has just one ASIC keep's me in my opinion, that channeling the 4 links to one bis ISL-Trunk is the better option.

What do you guys think?

Regards,
Ralph

External Moderator
Posts: 4,907
Registered: ‎02-23-2004

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

--->>>A colleague of mine has a differnet opinion.

 

and you are right, the colleague think wrong.

 

there is no matter from ASIC side who the trunk Group is configured / created /assigned

 

Additional, the best practicies is to create a Trunk Group in the same octet

 

i.e. 0-7 or 8-15 and so on.

 

 

TechHelp24
Occasional Contributor
Posts: 5
Registered: ‎10-01-2013

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

Thanks for your quick reply.

 

And what about the reliability of the ASIC's on the 5300?

If the 4 x 8Gig Trunkgroup is terminating on one sigle ASIC and this ASIC is going die, the trunk is dead.

Why not arguing with this opinion?

 

Regards,

Ralph

External Moderator
Posts: 4,907
Registered: ‎02-23-2004

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

ralph,

 

you main question was related to:

 

--->>>My opinion is, that it is better to connect the 6510 with one big ISL-Trunk using Ports 0-3....

 

and accordly I post the answer.

 

5300 is designed a bit different.

 

with in Total 9 GoldenEye Asic, 5 for Front-End and 4 for Back-End, each ASIC maintan 16 Ports from a Front-End side.

 

The ASIC is Front-End communicate with all 4 back-End ASIC, vice-versa the Back-End ASIC communicate back with the remain Front-End ASIC

 

From a Name are you germany resident ? if yes, send me a email with you phone number I'll try to explain in a Call

 

abongiorno@techhelp24.net

TechHelp24
Occasional Contributor
Posts: 5
Registered: ‎10-01-2013

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

Hey,

 

i am aware of the asic layout of the 5300, thats not my point.

My point is: would it make more sense in terms of reliability to connect 2 ISL-Trunks (each 2 x 8G) from the 6510 to the 5300 ?

The reason because i have to consider this is: availability.

When the ASIC in the 6510 is going to die, then the switch is gonna be useless because all ports are affected.

 

But lets imagine only one ASIC is going to die on the 5300. If i would have the 4 x 8G ISL Trunk connected to that ASIC, the only connection to the 6510 is going down. But when i split that one big trunk into 2 x 8G trunks and separate them to different ASIC's, there is the possibility to let 1 ASIC die, and the link from the 5300 to the 6510 would  be still available, even tho its just half the bandwidth.

 

I am just trying to take everything into consideration. What is the Pro's and what is the Con's of these 2 designs?

 

Regards,

Ralph

External Moderator
Posts: 4,907
Registered: ‎02-23-2004

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

[ Edited ]

Ralph,

 

what you want do discuss ?

 

->And what about the reliability of the ASIC's on the 5300?

->i am aware of the asic layout of the 5300, thats not my point.

 

continue:

 

-->>The reason because i have to consider this is: availability.

-->>When the ASIC in the 6510 is going to die, then the switch is gonna be useless because all ports are affected.

 

Is the ASIC defective, then you have to replace the entire switch, no matter if the ISL is connected to one or other octet group.

 

--->>>But lets imagine only one ASIC is going to die on the 5300. If i would have the 4 x 8G ISL Trunk connected to that ASIC, the only connection to the 6510 is going down.

 

NO!!!! it is not.

 

5300 ASIC design is like a spiderweb.

 

The ASIC on 5300 mantain 16 Port, but this not say mantain Port from number x to number y

 

with other word, the ASIC layout is Dynamic and not Static, theoretically, ONE Single ASIC can handle all 80 Port.

 

what is want to say, get the ASIC defective, the other ASIC cuntinue to handle the Port, but the switch get in oversubscription.

 

I hope this clarified a bit more you question

 

 

TechHelp24
Occasional Contributor
Posts: 5
Registered: ‎10-01-2013

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

Hello,

 

alright, now I see what is your point. I thought if the one ASIC who handles the 4x8Gig ISL Trunk dies, the Trunk goes down.

Now that makes sense. Would you generally recommend using 1 big ISL-Trunk instead of 2 if the Switch ASIC design is redundant like the one from the 5300?

 

Regards,

Ralph

Regular Contributor
Posts: 164
Registered: ‎05-11-2011

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

Sorry TechHelp24,

 

but you are totally wrong.

I have attached the ASIC-Layout for the B5300.

 

For trunking we have several criteria which have to be met. And one is:

All trunkmembers have to terminate on the same protgroup.

A portgroup only belongs to one ASIC. Otherwise the ASIC can not guarantee the IOD of the frames on a trunk.

So when the ASIC where the trunk is connected goes down, the whole trunk is down.

 

It is in Ralph's decision what can happen.

How often did you face outages of one ASIC? Once a day, a week, a year?

Mostly you will face outages of SFP or Fibercables. And then one big trunk is the better solution,

because an outage for 3 of 4 trunkmembers will not force an Fabric Rebuild.

 

 

Kind Regards
Ralf
External Moderator
Posts: 4,907
Registered: ‎02-23-2004

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

I know the design.


At this point, since you are the opinion I'm wrong as you say, would be love when you explain me "EXACTELY" what you see in this design.

 

Thanks for you support.

 

 

TechHelp24
Regular Contributor
Posts: 164
Registered: ‎05-11-2011

Re: ISL Trunk between 6510 and 5300 - Brocade Best Practice?

Hi TechHelp24,

 

you state:

The ASIC on 5300 mantain 16 Port, but this not say mantain Port from number x to number y

 

Not correct. Port 0 to 7 are on one ASIC. Port 8 to 15 are on the same ASIC.  So each Portgroup is on the same ASIC.

Otherwise the Ports will not build a trunk. Perform portbuffershow and you will see which Ports are belonging to the same ASIC.

 

with other word, the ASIC layout is Dynamic and not Static, theoretically, ONE Single ASIC can handle all 80 Port.

No, defnetly not.

 

what is want to say, get the ASIC defective, the other ASIC cuntinue to handle the Port, but the switch get in oversubscription.

No, totally wrong. A physical Port belongs to an ASIC. There is nothing dynamic. Perform portbuffershow and you will see the boundaries of the ASIC and the Ports.

 

 

Kind Regards
Ralf

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