passing the cisco ccna is easy with that material
EIGRP can load-balance across 6 unequal-cost links
Roter(config)#router eigrp 10
Roter(config-router)#maximum paths <1-6>
By default EIGRP has a maximum hop count of 100, but you can change this with:
Roter(config)#router eigrp 10
Roter(config-router)#metric maximum-hops <1-255>
Maximum hop count is used to limit the scope of the AS
EIGRP doesn’t use hop count in the path metric calculation
Only Bandwidth and Delay are used by default.
MTU size must be configured but it is not used in path selection. It is used in commands involving redistribution
Neighborship table: referred as the neighbor table, contains info about routers with whom neighborship relations have been formed.
Topology table: stores the route advertisements about every route in the internetwork received from each neighbor.
Route table: stores the routes that are currently used to make routing decisions.
There would be different table sets for each protocol that EIGRP is currently using.
Diffusing Update Algorithm is responsible for selecting and maintaining information about the best paths to each remote network.
This algorithm allows the following:
DUAL provides EIGRP with probably the fastest route convergence time.
EIGRP uses a Cisco proprietary protocol called Reliable Transport Protocol (RTP) to manage the communications between EIGRP – enabled routers.
The mechanism designed by Cisco leverages multicasts (224.0.0.10) and unicasts to deliver messages and track the receipt of the data.
EIGRP uses multicast to communicate with its neighbors. If EIGRP don’t receive a reply from a neighbor, it will switch to unicast to resend the same data. If it still doesn’t get a reply after 16 unicasts, the neighbor is declared dead.
This technique is called reliable multicast. Routers keep track of the info they send by assigning a sequence number to each packet. This is a way to detect the arrival of old, redundant, or out of sequence information.
This is an advanced distance-vector routing protocol, or even a hybrid protocol
Powerful features:
Different tables for each routed protocol
Routers become neighbors -> Hello packets
EIGRP support discontinuous networks but not by default
- show vtp password
- show vtp status
- show vlan brief
- domain name, password, and configuration revision (CR) must be the same on every switch
If CR (configuration revision) value is different, 2 solutions: change the domain name on the server => CR=0. Or, create or delete VLANs on the switch with the smaller CR until the value passes the value on the other switches
1. Change to VTP Server Mode
S(config)#vtp mode server
2. Domain name (case sensitive)
S(config)#vtp domain EasyCCNA
3. VTP password
S(config)#vtp password PaRoLA
4. Change mode to client or transparent
S(config)#vtp mode [client / transparent]
- one subinterface for each VLAN connected to a trunk port on the switch:
R(config)#int f0/1
R(config-if)#no ip address
R(config-if)#no shutdown
R(config-if)#int f0/1.3
R(config-subif)#encapsulation dot1q <1-4094 VLAN ID> 3
R(config-subif)#ip address 192.168.10.17 255.255.255.240
- the host in each VLAN must be assigned an address from their subnet range, and the default gateway would be the IP assigned to the router’s subinterface in tha VLAN ( 192.168.10.17 255.255.255.240)
S(config)#int f0/1
S(config-if)#switchport trunk allowed vlan ?
* WORD (VLAN IDs of the allowed VLANs)
* add (add VLANs to the current list)
* all
* except ( all VLANs except the following)
* none
* remove (remove VLANs from the current list
By default ALL VLANs are allowed
S(config-if)#switchport trunk allowed vlan remove 4
To go back to the default:
S(config-if)#switchport trunk allowed vlan all
or
S(config-if)#no switchport trunk allowed vlan
