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1.1 Ethernet Switching

EtherChannel 101

An etherchannel is a logical port that consists of multiple links bundled into a single logical link. To have a working etherchannel you must use static config or a negotiation protocol (LACP or PAgP). All ports in an EtherChannel must operate at the same speed and duplex. When an EtherChannel …

VLANs

1. Supported VLANs Supported VLANs: 1-4094 Optional parameters: To verify: 1.1 Normal Range vs Extended Range Normal Range VLANs: 1-1005* – Supported by VTP v1,v2,v3 in all modes. Extended Range VLANs: 1006-4094 – Only supported in Transparent mode by VTPv1 and v2, and in all modes by VTP v3. * …

Private VLANs

Private VLANs partitions a regular VLAN domain into subdomains. Such a subdomain is created when a primary VLAN is paired with a secondary VLAN. Only a switch in VTP Transparent mode supports Private VLANs 1. Primary VLAN To set a VLAN as Primary VLAN, use: After the secondary VLANs are …

VTP 101

1. How it works VTP (VLAN Trunking Protocol) is used to advertise VLAN information between connected switches in a network. VTP messages are sent only on trunk ports. VTP advertises the VLAN_ID, VLAN_NAME, VLAN_TYPE and VLAN_STATE information for each VLAN. VTP doesn’t send any information regarding port assignment to VLANs. …

802.1s – MSTP

The number of STP or RSTP instances that can run on a switch is limited. It is usually enough for most implementations but if you need to run STP on more VLANs, then MSTP is the solution. MSTP maps multiple VLANs to the same STP instance. Even when PVST or …

802.1w – RSTP

Rapid Spanning Tree is an updated version of the original Spanning Tree protocol, standardized as 802.1w. It includes many of the Cisco proprietary features of PVST+. RSTP is backwards compatible with 802.1d STP but it has a few new features. To enable RSTP, use: 1. New features in RSTP 1.1 …

802.1d – STP

1. BPDUs – Bridge Protocol Data Units BPDUs are sent as 802.3 frames with a source address equal to the MAC address of the sending switch port and with a destination address of 01:80:C2:00:00:00. The LLC header has the DSAP and SSAP fields set to 0x42. Protocol ID is set …