A fairly simple approach to providing uplink resilience. There are methods like EAPS or MLAG to give you uplink resilience, but sometimes you just need something simple.
A redundant physical (or “Redundant Phy”) is essentially two uplinks to upstream switches and to avoid a loop, the downstream switch (i.e. the one with the redundant phy enabled) monitors and keeps one uplink in a blocking state until such a time that the active link fails, in which case the surviving link becomes traffic.
configure ports primaryPort redundant secondaryPort {link [on | off]}So as an example, let’s say you have two ports 24 and 25 used for the uplink. You’d put port 24 as the primaryPort and port 25 as the secondaryPort.
It is important to remember that you must have the necessary VLANs tagged on BOTH ports to avoid any issues.
The option for “Link” which can be on or off, could be important to you, it doesn’t affect the way the resilience works or effect traffic flow, but what it does give you is better visibility. I normally set the “Link” to “on”, as we monitor uplinks we’d know if the secondary/backup link was to fail and we can remediate it. If you set it to “off” you may not know when it fails until you need to use it!
https://extremeportal.force.com/ExtrArticleDetail?an=000078855