Not sure exactly what your environment looks like, but we encountered something similar when trunking Cisco-DELL and Cisco-Juniper switches. We run RSTP on DELL and Juniper switches, but RPVST+ on Cisco. In the beginning we just allow those VLANS we need between Cisco-DELL/Juniper switches, then encountered unexpected err-disable / link drop things. Later we figured Cisco always carry default VLAN (VLAN-1) untagged through trunk ports. Hence we manually "explicitly" add/allow Native-VLAN-1 (untagged) on all trunk ports in all switches. Problem solved.
On Fri, Apr 6, 2018 at 11:59 AM, Mark Milhollan <m...@pixelgate.net> wrote: > Sounds like the Juniper is leaking a "default" BPDU as it resets the > various internal chip configurations, which the Cisco receives thus > triggering the err-disable. > > > /mark -- -- Michel~
