Unicast flooding issue with 3750g
The Cisco Catalyst WS-C3750X-12S-S 3750 v2 Series are next-generation energy-efficient Layer 3 Fast Ethernet stackable switches. These new switches support Cisco EnergyWise technology, which helps you manage the power consumption of your network, thereby reducing energy costs and carbon footprint.
Sniffing on an host interface connected to my 3750g I get many unicast packet destined to different hosts and not coming from the machine where I started the sniffing task. Doing some investigations I realized that several mac addresses was disappearing too fast from the mac address table: c3750G-48T-ST#show mac-address-table address 00:26:9e:3c:7e:6a Mac Address Table ——————————————- Vlan Mac Address Type Ports —- ———– ——– —– 1 0026.9e3c.7e6a DYNAMIC Po10 Total Mac Addresses for this criterion: 1 and after between 10 and 20 seconds: c3750G-48T-ST#show mac-address-table address 00:26:9e:3c:7e:6a Mac Address Table ——————————————- Vlan Mac Address Type Ports —- ———– ——– —– c3750G-48T-ST# The aging time is the default one: c3750G-48T-ST#show mac-address-table aging-time vlan 1 Global Aging Time: 300 Vlan Aging Time —- ———- 1 300 It does not look like a problem of spanning tree,Cheap Canada Goose Outlet Parkas Youth as the topology does not change that often: c3750G-48T-ST#show spanning-tree vlan 1 detail
from Topology change flag not set,
detected flag not set Number of topology changes 313 last change occurred 13:42:30 ago from Port-channel1 Times: hold 1,
topology change 35, notification 2 Timers: hello 0,Kids Canada Goose Outlet topology change 0,Canada Goose Outlet Vest For Youth notification 0,
Men Canada Goose Outlet aging 300 WS-C3750V2-48PS-S