VOSS switch redundancy

[Alex221]

Hello all,

We are planning a hardware refresh and have purchased four 7520-48Y-8C-FabricEngine switches (version 9.0.5.1).

Two of these will be utilized as Core switches, while the other two will serve as Data Center (DC) switches. The DC switches will be connected to all servers and storage devices. The Core switches are configured with vIST.

I attempted to establish SMLT between interfaces 1/49 and 1/50 on the Core switches, but I cannot use SPBM on those interfaces. If I configure ISIS on 1/49 and 1/50, then SMLT becomes unavailable. I understand that stacking is not possible on VOSS switches, which means we cannot configure both Core switches as a single logical unit.

One potential solution I am considering is to create a second vIST between the DC switches.

Could you please advise if there is any way to maintain the current design, or should I go ahead and create a second vIST?

Thanks,
Alex

[Phil_]

Hi Alex,

Why don't you use IS-IS NNI links(You don't need MLTs or SMLTS for IS-IS links. MLTs are only recommended if multiple physical connections go from one node to the same other node.) between the core switches and the DC switches? Using vIST requires a fabric anyway. You could also establish a vIST in the DC environment without the need for a crosslink between the two DC switches.

My recommendation is to configure the following:

Core 1:

Spoiler

enable
conf t
interface gigabitEthernet 1/49,1/50
isis
isis spbm 1
isis enable
no shutdown
exit
save config

Core 2:

Spoiler

enable
conf t
interface gigabitEthernet 1/49,1/50
isis
isis spbm 1
isis enable
no shutdown
exit
save config

DC 1:

Spoiler

enable
conf t
interface gigabitEthernet 1/49,1/50
isis
isis spbm 1
isis enable
no shutdown
exit
save config

# +vIST Configuration

DC 2:

Spoiler

enable
conf t
interface gigabitEthernet 1/49,1/50
isis
isis spbm 1
isis enable
no shutdown
exit
save config

# +vIST Configuration

Best regards,
Philipp