Introduction to Gateway Redundancy


(Rene Molenaar) #1

This topic is to discuss the following lesson:


(Jason W) #2

Can you run virtual gateway redundancy (HSRP, VRRP, GLBP) over access – to – distribution lines that are running etherchannel as well?


(Andrew P) #3

Jason,
This depends on how the access layer connects to the distribution layer. A single Etherchannel is not supported between one physical switch and two different physical switches (unless those two switches using Stackwise, VSS, or vPC). By this, I meaning the following is NOT allowed:


                        ---------Distribution SW1 
Access ---- Etherchannel                         --------VRRP
                        ---------Distribution SW2

You can, however, have Etherchanel across two links that connect two switches together. So, in the case below, Access SW1 is using multiple physical links bundled as Etherchannel to Dist SW1 and another set of multiple physical links bundled to Dist SW2.

Access SW1---Etherchannel #1-----Dist SW1
                                          --------VRRP
Access SW1---Etherchannel #2-----Dist SW2

In this case, you could setup HSRP/VRRP/GLBP between Dist SW1 and SW2 for gateway redundancy (assuming the Dist switches support layer 3).