IRF 2 on A7500

[manuel.bitzi]

Hi Sindibade

MAD is not necesary but recomanded to recover and avoid a split brain.

I'dont use LDAP MAD because I had problems in the past and the third device (connected by LA) has to support LDAP MAD too. I use BFD MAD => it is simple and works great. BFD-MAD uses a third link (i.e. a cheap cupper link) between the IRF members to shut down a possible second master in the IRF.

See the manual for the configuration steps.

br

Manuel

[sindibade_1]

I think that i have the same problem with LACP MAD, because i use the E5500G at the access layer and E5500G LA doesn't support LACP MAD.

but in my case if i use just BFD MAD will using LA on uplinks betwen A7506 and E5500G switchs can't make a problem when a virtual switch split occur?

regards

[manuel.bitzi]

The access switch does not affect the BFD MAD. BFD MAD will detect a split brain and deactivates the second master untill the splitbrain is solved. Then it activates the second irf-member and forces a resync.

br

Manuel

[sindibade_1]

Best regards

[RajRaj]

Implementing BFD MAD and LACP MAD is recommended to avoid split brain scenario.

[mnantel]

The switching fabric is always active on all SRPUs that are not in a failed state, on all members of an IRF pair (and later on an IRF quad) of 7500s.

On a 7506 chassis, each 384Gbps SRPU will provide 24Gbps (half-duplex) of bandwidth per slot. Redundant SRPUs are therefore required to avoid 2:1 oversubscription for 48 port Gbps or quad 10Gbps LPUs.

On a 7510 chassis, each 384Gbps SRPU will provide 12Gbps (HDX) of bandwidth per slot. Each 768Gbps SRPU will provide 24Gbps (HDX) of bandwidth per slot. If you the simple math, you can have anywhere from 4:1 oversubscription with single 384Gbps SRPU up to 1:1 with dual 768Gbps SRPUs.

As a general rule of thumb, don't bother selling SA modules and aim to sell SC and above due to the routing limitations highlighted by another poster. It was suggested to me that LPUs revert to the common lowest denominator when combining module types with regards to table capacities so in any scenario be mindful of your expected requirements in that regard when building 7500 chassis designs.

When answering non-blocking requirements, the 7500 family is to this date going to provide that for 48 ports gig linecards and 4 port 10Gbps linecards. Current backplane architecture (2 XGBUS per slot with each 4 XAUI clocked at 3.125Gbps) does not suggest future capacity upgrade will be possible for this chassis. We have the 9500, 12500 and now the new 10500 for customers with higher 10Gbps density requirements.