I have a issue in my network. In terms of OSI I am OK in the physical layer. My link is OK because I tested connecting a computer on a fiber link, and I was able to surf the Internet, but when I make a connection between two Cisco switches, I just have CDP – there is no propagation of VLANs.
There is something even stranger. I have a successful ping in a way. Example: I have a Switches A and B connected through that link. I can ping from B to A and get an answer, but ping doesn't work if I ping from A to B.
It seems very weird to me. I believe it is a VLAN problem, but I do not understand because I can't successfully ping both ways.
I verified that I have the same configurations on both switch ports. I have switchport mode trunk and the native VLAN is 1. I think that the problem is because of a broadcast storm, but I do not know how to verify that. The other situation that I have in my network is this is a multivendor network. My "core" switch is a 3Com. I have Cisco switches, HP switches and TP-Link switches with RSTP.
Should I have a same version of STP in all switches? Could it be a physical problem? Could I have problems with the fiber link? In the moment when the fail occurred, a person was working near to the rack where the fiber ends. I have two transceivers, and I always test between gigabit ethernet ports.
Best Answer
You should really run the same version of STP on all the switches. That means converting the Cisco switches to the same STP version as the other switches. Cisco has many documents about PVST and MST interactions if you search for them, and there is this one: Configuration example to migrate Spanning Tree from PVST+ to MST