Connecting a SG200 (access) to 2 SG300 (core/distribution) with redundancy and load balancing

[luca.smeriglio]

Hello,

I've read the Cisco design guide but couldn't find a proper configuration example for this scenario, sorry if this seems quite basic...

1)

I have two SG300-10SFP I'd like to use as Core (collapsed core/distribution) and a few SG200-50P as access switches.

As I understand it, to get redundancy, I need to connect the two SG300 together and every SG200 to both SG300.

But this will create a loop and spanning tree will block one of two links, isn't it ?

How can I get a redundant, LOAD BALANCED and loop free scenario with this basic architecture ?

(couldn't find info on etherchanel on these SMB models)

Any links to some real life configuration examples with two SG300 as Core and SG200 as Access would help A LOT :-)

2)

The SG300 in L3 mode seems limited to only 10 static routes.

Our routing table is bigger than that, should we keep the SG300 in L2 mode and use a router (on a stick) instead ?

Sorry for these basic questions

Many thanks for your help !

Have a great Day :-)

Luca

[Austin Sabio · Accepted solution]

Link aggregation is supported on both SG200 and SG300. 

SG200-Datasheet

Port grouping

Support for IEEE 802.3ad Link Aggregation Control Protocol (LACP) ●  Up to 4 groups ●  Up to 8 ports per group with 16 candidate ports for each (dynamic) 802.3ad link aggregation

http://www.cisco.com/c/en/us/products/collateral/switches/small-business-200-series-smart-switches/data_sheet_c78-634369.html

How? SG200-CLI Reference -Link Aggregation Page 199.

http://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbss/sf200e/command_line_reference/OL-22850.pdf

SG300-Datasheet

Port grouping

Support for IEEE 802.3ad Link Aggregation Control Protocol (LACP) ●  Up to 8 groups ●  Up to 8 ports per group with 16 candidate ports for each (dynamic) 802.3ad link aggregation

http://www.cisco.com/c/en/us/products/collateral/switches/small-business-smart-switches/data_sheet_c78-610061.html

How? SG300--CLI Reference -Port Channel Page 736

http://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/sf30x_sg30x/administration_guide/CLI_300.pdf

Also, I would definitely recommend a router for layer-3 full feature set but SG300 can do the job statically. 

IPv4 routing

Wirespeed routing of IPv4 packets Up to 512 static routes and up to 128 IP interfaces

http://www.cisco.com/c/en/us/products/collateral/switches/small-business-smart-switches/data_sheet_c78-610061.html

Please rate if helpful to benefit others. Good luck!

[luca.smeriglio]

Hello, thank you for your detailed and helpful answer, very appreciated !

OK for LAG/LACP and load balancing, but it's still not 100% clear about the loop free scenario.

If we connect the 2 SG300 (a and b) together, and one SG200 to SG300-a and SG300-b, this will create a loop, wouldn'it ? (see attached image)

How can we avoid that loop ?

Many thanks for your help !

Luca

[Austin Sabio]

Portchannel across multiple switches design is not possible/supported. Portchannels need to be on the same switch. However, certain platform allows this design such as Nexus VPC or 6500s with VSS.