Etherchannel L2 vs L3
Share this page:PAgP (Port Aggregation Protocol) - Cisco Prop. DESIRABLE or AUTO or NONEGOTIATE
*in case the link is configured as ACCESS, or the “switchport nonegotiate” command
- Protocol Value: 0x0104
- Same multicast group MAC like CDP
LACP (Link Aggregation Control Protocol) - 802.3ad - ACTIVE or PASSIVE
- Multicast MAC: 01-80-C2-00-00-02
- During Detection transmits packets every second
LACP>
Check the DEFAULT PARAMETERS:
2#show lacp 1 internal
Flags: S - Device is requesting Slow LACPDUs
F - Device is requesting Fast LACPDUs
A - Device is in Active mode P - Device is in Passive mode
Channel group 1
LACP port Admin Oper Port Port
Port Flags State Priority Key Key Number State
Gi3/0/19 SA bndl 32768 0x1 0x1 0x7F 0x3D
Gi3/0/20 SA bndl 32768 0x1 0x1 0x80 0x3D
“ON” - Doesnt use LACP or PaGP. BOTH sides MUST BE ON!!!
#do show etherch protocol
Channel-group listing:
———————-
Group: 13
-———
Protocol: - (Mode ON)
You can configure MAX 16 PORTS, out of which:
MAXIMUM 8 ACTIVE PORTS, and the other HOT STANDBY (activate if one of the first 8 fail). Which ones belong to
the ACTIVE group depends on the LACP PRIORITY, that can be configured:
(config-if)#lacp port-priority 1 <— LOWER IS BETTER!!! (default is 32768)
L3 ETHERCHANNEL: Configure the Port-Channel interface statically, and all L3 configuration under it
Summary: 32 Po32(RU) - Gi1/0/23(P) Gi1/0/24(P)
L2 ETHERCHANNEL: LOGICAL INTERFACE CREATED AUTOMATICALLY. Best Practice (CONFIGURATION):
- Default Interface
- Channel Protocol and Group on physical interface (this creates Port Channel)
- Configure TRUNKING ENCAPSULATION under the PORT CHANNEL directly
- SHUT -> NO SHUT on PHYSICAL INTERFACES
Summary: 24 Po24(SU) PAgP Gi1/0/21(P) Gi1/0/22(P)
* “show interface trunk” Will show only Port Channel, but “show interface XX switchport” will show that the INT IS TRUNK
LOAD BALANCE the Etherchannel>
*CONFIGURED in the Global Config mode:
** (config)#port-channel load-balance ?**
** dst-ip Dst IP Addr**
** dst-mac Dst Mac Addr**
** src-dst-ip Src XOR Dst IP Addr**
** src-dst-mac Src XOR Dst Mac Addr**
** src-ip Src IP Addr**
** src-mac Src Mac Addr**
** #show etherchannel load-balance**
**EtherChannel Load-Balancing Configuration:**
** dst-mac**
EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Destination MAC address
IPv4: Destination MAC address
IPv6: Destination MAC address