CCNA Training

  CCNA 200-301 v1.1 Curriculum Domain Weight Network Fundamentals 20% Network Access 20% IP Connectivity 25% IP Services 10% Security Fundamentals 15% 1. Network Fundamentals (20%) OSI and TCP/IP models Routers, Layer 2/Layer 3 switches Firewalls, IPS, wireless APs, controllers IPv4 and IPv6 addressing Subnetting Cabling (UTP, fiber) MAC address table ARP Wireless basics Virtualization Cloud networking basics 2. Network Access (20%) VLANs Trunking (802.1Q) Inter-VLAN routing EtherChannel (LACP) Rapid PVST+ PortFast BPDU Guard Root Guard CDP and LLDP Wireless LAN architecture WLAN configuration SSH, HTTPS, TACACS+, RADIUS 3. IP Connectivity (25%) Routing table interpretation Longest prefix match Administrative distance Static routes Default routes Floating static routes Single-area OSPFv2 DR/BDR election Router ID First Hop Redundancy Protocols (FHRPs) 4. IP Services (10%) NAT/PAT DHCP DNS NTP SN...

 In Open Shortest Path First (OSPF) , DR (Designated Router) and BDR (Backup Designated Router) are elected to reduce the amount of OSPF traffic on multi-access networks like Ethernet. Why are DR and BDR needed? Imagine 5 routers connected to the same Ethernet switch. Example: Ethernet LAN (Multi-access) Switch +-----+-----+ | | | R1 R2 R3 | | | R4 R5 All five routers are connected to the same Ethernet switch and are on the same subnet Without a DR: Every router forms a neighbor relationship with every other router. Number of adjacencies = n(n−1)/2 For 5 routers: R1 ↔ R2 R1 ↔ R3 R1 ↔ R4 R1 ↔ R5 R2 ↔ R3 R2 ↔ R4 R2 ↔ R5 R3 ↔ R4 R3 ↔ R5 R4 ↔ R5 That's 10 adjacencies . With a DR: R2 | R3 ---- DR ---- R4 | R5 | R1 Each router forms a full adjacency only with the DR (and BDR), greatly reducing overhead. DR and BDR election The election is based on: ...

Cisco CCNA Port Security Lab that you can practice in Cisco Packet Tracer , Cisco Modeling Labs (CML) , or on real equipment. Topology PC1 | Fa0/1 +---------+ | Switch | +---------+ PC1 → Switch Fa0/1 IP Address (optional): PC1: 192.168.1.10/24 Step 1: Configure the Interface Switch> enable Switch # configure terminal Switch(config) # interface fastethernet0/1 Switch(config-if) # switchport mode access Step 2: Enable Port Security Switch(config-if) # switchport port-security Step 3: Allow Only One MAC Address Switch(config-if) # switchport port-security maximum 1 Step 4: Learn the MAC Address Automatically Switch(config-if) # switchport port-security mac-address sticky The switch learns the first connected device's MAC address and saves it as a secure MAC. Step 5: Configure the Violation Mode Switch(config-if) # switchport port-security violation shutdown Other options are: protect restrict shutdown (default and most common...

  GRE is to run dynamic routing protocols across another network . For example: Branch Router -------- Internet -------- HQ Router | | OSPF OSPF Normally, the internet won't carry routing protocol packets between your routers. A GRE tunnel creates a virtual point-to-point link: Branch Router ===== GRE Tunnel ===== HQ Router Now both routers behave as if they're connected by a dedicated cable, allowing protocols like OSPF or EIGRP to exchange routes. Common uses of GRE Running dynamic routing protocols across an IP network (its most common use). Transporting multicast and broadcast traffic , which plain IP forwarding often doesn't support. Connecting branch offices over an existing IP network. Carrying different Layer 3 protocols inside IP. Creating overlay networks between routers. Example Suppose a company has: Headquarters in one city Branch office in another An internet ...

 Routing loops when same pattern of ip address appear in tracert  192.168.1.10 path  Swtiching loops  - Broadcast mac ffff.ffff.fffff  and also  link utilization is high and network is down.. 

 fast.com Sampling 10 times and take average..