Packet tracer topology

[som3awy]

I have a few questions and I hope someone helps me. If you have a topology such as the one above, how would you configure the distribution switches 1 and 2 and will all uplinks to the distribution switches be active??  

Thanks in advance.

[Deepak Kumar]

Hi,

This is Packet Tracer so there is some limitations as you cannot configure the stack between your distribution switches. So now you are having only few choices as use the routed port (L3) between your access switch and distribution switch with static or dynamic routing protocol so you can avoid the STP limitations. 

Regards,

Deepak Kumar

[georgehewittuk1]

Hi,

Beacuse of loops causing broadcast storms/mayhem! -  Having all "uplinks" on layer 2 in packet tracer running on the same broadcast domain is not possibly/advised. STP (spanning tree protocol) protects layer 2 networks from this and you can read about this below. But in short it ultimately makes one route to everywhere based on the cost (most efficient path) but this can be set manually in configuration.

https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/5234-5.html

You could technically utilise all links by having different VLANs use different links to maximise bandwidth effeciency. And of course those uplinks are always relevent for redundancy anyway. You can read about this in the later literations of STP.

Hope this helps.

Thanks

George

[Joseph W. Doherty]

You could set you STP topology so that your distribution cross link (in red in your diagram) would block first. This also assumes you don't have the same VLAN across multiple edge switches. (BTW: I'm not suggesting such is a best practice design.)

[som3awy]

Would a basic config. for this be something like, on both dist. switches, create 3 SVIs for VLANs 10, 20 and 30, apply HSRP and set the ports connecting the switches to trunk ports.

Also, if for example dist. switch 1 is acting as the active router for VLAN 10, how would traffic flow if I ping PC4 (VLAN 30) from PC1 (VLAN10) ? And what would the difference be if the red link between the dist. switch was a L3 instead of a L2?

[Joseph W. Doherty]

Yes, you could use trunks, but again assuming you limit VLAN 10 to SW0, VLAN 20 to SW1 and VLAN 30 to SW2, you could also use access ports to the downstream switches.

With the above, if PC1 tried to ping PC4, it would go to its active HSRP GW, which would route it, on the same L3 switch, to VLAN 30, and then the ping would go to SW2 and then to PC4.

The RED link woudn't come into play (assuming all else is "up") if it was L3 or blocked at L2.