The IEEE 802.1Q specification defines a standards-based mechanism not only to provide VLAN tagging but also for Class of Service (CoS) across Ethernet networks. Because the sound quality of an IP phone call can deteriorate if the data is sent without any sort of protection, the switch supports Quality of Service (QoS) based on IEEE …
Monthly Archive: April 2017
Apr 07
Where Cisco catalyst switch stores VLAN information?
The short answer is: VLANs 1-1005 are stores in valn.dat file stored in FLASH VLANs 1006-4094 are stored in running-config and moved to starup-config after configuration is saved. The full story is a bit more complicated and involves VTP as well. Here are details. VLAN or VTP configuration changes in CatOS are written to NVRAM …