Category Archives: L2 switch

L2 Security

Interface command “switchport port-security” allows a single MAC to be learned on that port. Interface command “switchport port-security maximum x” to allow ‘x’ mac to learn on that port. To define static sticky MAC on an interface, use “switchport port-security … Continue reading

Posted in L2 switch | Leave a comment

Wireless LAN

IEEE 802.11 – standards for Wireless LAN ( WLAN). Every wireless connection is in half-duplex mode because transmitting and receiving stations use the same frequency The IEEE 802.11 standards use the CSMA/CA method to avoid collisions.

Posted in L2 switch | Leave a comment

IP Phone

Power over Ethernet (POE): PoE devices like IP phones receive power from the connected switch. The switch can provide power in two different methods: Cisco Inline power (ILP): Cisco proprietary. IEEE 802.3af: Based on IEEE standard.

Posted in IOS, L2 switch | Tagged , , | Leave a comment

Software and hardware redundancy

Software Redundancy: Multilayer switches act as gateway for end users. First Hop Redundancy protocols (FHRP) are available to provide redundancy to end users. FHRP includes;

Posted in IOS, L2 switch | Tagged , , , , , | Leave a comment

Hierarchical Network Design

Three Layer Model: Access layer: Where end users are connected. For intra-vlan routing. Distribution Layer: where access layer switches are aggregated. For inter-VLAN routing Core Layer: where distribution layer switches are aggregated. Center to all users.

Posted in IOS, L2 switch | Tagged , , , , | Leave a comment

Advanced STP: RSTP and MSTP

Rapid Spanning Tree Protocol IEEE 802.1w defines RSTP. Works based on 802.1d principal concept. BPDU version field set to 2. Root bridge is elected as in 802.1d Port Roles:

Posted in IOS, L2 switch | Tagged , , | Leave a comment

STP: 802.1d and PVST

Traditional Spanning Tree Protocol: To avoid bridging loops in L2 network with redundant paths. Defined in IEEE 802.1d standard. Bridge Protocol Data Unit (BPDU)s’ are used to communicate among all switches(bridges). SRC MAC = Mac address of the port on … Continue reading

Posted in IOS, L2 switch | Tagged , , , , , | 2 Comments

Etherchannel: PAgP and LACP

Can bundle up to 8 interfaces to a port-channel. Maximum number of port-channels in C3560 can be 48.

Posted in IOS, L2 switch | Tagged , , | Leave a comment

VLAN trunking protocol (VTP)

Reduce admin work by distributing VLAN information from VTP server to clients. Works only on trunk interface. Packets are sent either in ISL frames or IEEE802.1q frames. VTP packets are addressed to the destination MAC address: 01-00-0C-CC-CC-CC

Posted in IOS, L2 switch | Tagged , | Leave a comment

Private VLAN: Concept and Cisco IOS/F10 configuration

Why we need private VLAN: All hosts in a single VLAN can communicate with each other via L2. There may be situations where we need hosts in a vlan shouldn’t communicate with each other in the same VLAN. Example: In … Continue reading

Posted in Force10, IOS, L2 switch | Tagged , , , | 3 Comments