Question on using passive stacking cables on two or more SR2148P switches.

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Hi, is there anything special I have to do when using passive stacking cables between two or more SR2148P switches? Every time I plug in two switches the connections go down. I don't know if this is because the switches are trying to route the connection to the gateway via the passive cable. If so, should I set the gateway from one switch to another? Thanks.
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Juan Fuentes

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Posted 2 years ago

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Mike Kouri, Official Rep

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Yes; don't do that. Stacking switches to form one logical unit is not supported.
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Juan Fuentes

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Thanks Mike, so I'm guessing ports 49 - 52 are reserved for fiber connectors only then? Thanks for the quick reply.
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Mike Kouri, Official Rep

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I had to go find one on someone's desk. Yes, those are standard SFP sockets for use (typically) for long-distance runs back to a centralized switch or the corporate backbone, when twisted pair cables will be too short. Other than the physical characteristics, they are just four more "ethernet" ports for you to use as you wish.
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John Haithwaite

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Set them up as Trunk Ports. Personally I would set them up in pairs and use a couple of 0.5m fibre patch cables with 1Gb SFP modules to get a 2Gb link using LACP or similar. Trunks can then pass all the VLANs etc.
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BJ, Champ

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No LACP support...yet
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Jay Auger

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I've got 8x SR2148P's connected using 2x DACs (direct-attached-copper/twinax) each to a pair of Brocade VDX 6740's. They are configured as LAGs on each end.  Here's a sample config from both sides:

AEROHIVE SWITCH:

SR2148P#sh run | inc agg
agg 1
interface eth1/49 agg 1
interface eth1/50 agg 1
interface agg1 switchport mode trunk
interface agg1 switchport trunk native vlan 110
interface agg1 switchport trunk allow vlan 17 - 20
interface agg1 switchport trunk allow vlan 25 - 26
interface agg1 switchport trunk allow vlan 78
interface agg1 switchport trunk allow vlan 110
interface agg1 switchport trunk allow vlan 911
interface agg1 switchport trunk allow vlan 915
no interface agg1 client-report enable
interface agg1 qos-classifier uplink-portchannel
interface agg1 qos-marker uplink-portchannel

BROCADE CORE:

BROCADE-VDX6740# show running-config interface Port-channel 64
interface Port-channel 64
 no vlag ignore-split
 description SR2148P/agg1
 switchport
 switchport mode trunk
 switchport trunk allowed vlan add 17-20,25-26,78,110,911
 no switchport trunk tag native-vlan
 switchport trunk native-vlan 110
 spanning-tree shutdown
 no shutdown
!
BROCADE-VDX6740# sh run int te 1/0/18
interface TenGigabitEthernet 1/0/18
 description SR2148P/eth1/49
 channel-group 64 mode on type standard
 no fabric isl enable
 no fabric trunk enable
 fabric neighbor-discovery disable
 storm-control ingress broadcast limit-bps 1000000 monitor
 no shutdown
!
BROCADE-VDX6740# sh run int te 2/0/18
interface TenGigabitEthernet 2/0/18
 description SR2148P/eth1/50
 channel-group 64 mode on type standard
 no fabric isl enable
 no fabric trunk enable
 fabric neighbor-discovery disable
 storm-control ingress broadcast limit-bps 1000000 monitor
 no shutdown
!

~~~~~~~~

Juan, In your situation if you're connecting multiple SR2148P's together using multiple cables, then you could be having spanning-tree blocking a port on you.

Jay