Link Aggregation & HSRP Flashcards
Combine several physical links between switches to be a single logical link to increase the overall speed of switch-to-switch communication
Link aggregation
Advantages of link aggregation / etherchannel
Performs load balancing within the aggregated links
Provides redundancy within the aggregated links
What are the etherchannel protocols types ?
LACP (open standard)
PagP (Cisco proprietary)
Etherchannel Restrictions
Interface types cannot be mixed eg, Fast ethernet and Gigabit ethernet
What are the PagP modes
On
Desirable
Auto
What are the LACP modes ?
On
Active
Passive
Channel Establishment
Active/Passive - Active
Yes - LACP
Channel Establishment
On - Desirable
No - PagP
Channel Establishment
Passive/on - Passive
No - LACP
Channel Establishment
Auto/Desirable - Desirable
Yes - PagP
What is the command to check the status of Etherchannel configuration
S1#show etherchannel summary
Command to verify the interface status
S1#show interface port-channel <>
Troubleshooting Etherchannel
Each interface must have the same speed, duplex mode, native and allowed vlans on trunk, assigned to same vlan.
Cisco proprietary FHRP designed to allow for transparent failover of a first-hop IPv4 device
HSRP
Open Standard FHRP. dynamically assigns responsibility for one or more virtual routers to the VRRP routers on IPv4 LAN
VRPP
Cisco proprietary FHRP which protects data traffic from failed router or circuit allowing load balancing between a group of redundant routers
GLBP ( Gateway Load Balancing Protocol)
HSRP Priority
Determine active router
Default priority 100
range to 0 to 255 and router with highest priority will become active
Ability of HSRP router to trigger the re-election process
Preemption
HSRP verification
show standby
When a range of ports is being configured for EtherChannel, which mode will configure LACP on a port only if the port receives LACP packets from another device?
Passive
Advantages of Etherchannel
Provides consistency in
the configuration of the physical links
Spanning tree protocol views the physical links in ehterchannel as one logical link
Which two channel group modes would place an interface in a negotiating state using PAgP?
Desirable
Auto
What are two load-balancing methods in the EtherChannel technology?
Source IP to destination IP
Source MAC to Destination MAC
