The industry standard LACP is used for link aggregation between multiple network nodes to ensure redundancy and availiability. This lab will discuss and demonstrate the configuration and verification of LACP EtherChannel.
In the world of EtherChannel technology there are two types of dynamic channel-group protocols, Port Aggregation Protocol (PAgP) which is a Cisco Proprietary protocol and Link Aggregation Control Protocol (LACP) which is the IEEE standard.
LACP uses two types of port modes; active and passive. LACP active mode unconditionally forms a LACP dynamic ether-channel whereas passive will only accept LACP negotiation attempts from a device set to active.
LACP is commonly used for Server NIC teaming with Broadcom or Intel NIC’s that support 802.3ad (LACP). This ensure that the server has two connections to a switch rather it is a stacked switch for redundancy or a blade chassis whereas the links are on different blades. If one nic goes down, connectivity to the server is not lost.
In this lab you will familiarize yourself with the following commands;
|channel-group # mode active||This command when executed in interface configuration mode sets the channel-group number and LACP mode to aggressively attempt to form a LACP EtherChannel. If negotiations fail, the EtherChannel will not pass traffic.|
|channel-group # mode passive||This command when executed in interface configuration mode sets the channel-group number and LACP mode to listen for LACP packets but not aggressively and unconditionally form an EtherChannel using LACP.|
|show etherchannel summary||This command when executed from user or privileged mode will display a summary of local EtherChannel(s) properties such as the channel-group number, ports in the channel group, and the role the ports the play.|
|show etherchannel detail||This command when executed from user or privileged mode will display detailed information relating to the EtherChannel(s) local to the device.|
Step 1 . – Configure SW1’s Fa0/10, Fa0/11 and Fa0/12 interfaces to aggressively attempt to form a LACP EtherChannel.
For this you’ll use the channel-group # mode active command in interface or interface range configuration mode as shown below;
SW1 con0 is now available Press RETURN to get started. SW1>enable SW1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. SW1(config)#interface range f0/10 - 12 SW1(config-if-range)#no shut SW1(config-if-range)#channel-group 1 mode active Creating a port-channel interface Port-channel 1 SW1(config-if-range)#end SW1#
Step 2. – Configure SW2’s Fa0/10, Fa0/11 and Fa0/12 interfaces to form a PAgP EtherChannel only when a device attempts to negotiate a LACP EtherChannel only.
For this you’ll use the channel-group # mode passive command in interface or interface range configuration mode as shown below;
SW2 con0 is now available Press RETURN to get started. SW2>enable SW2#configure terminal Enter configuration commands, one per line. End with CNTL/Z. SW2(config)#interface range f0/10 - 12 SW2(config-if-range)#no shut SW2(config-if-range)#channel-group 1 mode passive Creating a port-channel interface Port-channel 1 SW2(config-if-range)#end SW2#
Step 3. – Verify that interfaces Fa0/10, Fa0/11 and Fa0/12 on SW1 formed a LACP EtherChannel correctly.
To verify the EtherChannel LACP configuration you can use either the show etherchannel summary or show etherchannel detail command in user or privileged mode as shown below;
SW1#show etherchannel summary Flags: D - down P - bundled in port-channel I - stand-alone s - suspended H - Hot-standby (LACP only) R - Layer3 S - Layer2 U - in use f - failed to allocate aggregator M - not in use, minimum links not met u - unsuitable for bundling w - waiting to be aggregated d - default port Number of channel-groups in use: 1 Number of aggregators: 1 Group Port-channel Protocol Ports ------+-------------+-----------+----------------------------- 1 Po1(SU) LACP Fa0/10(P) Fa0/11(P) Fa0/12(P) SW1#
Step 4. – Verify IP communication over the newly formed LACP Ether-Channel by pinging R2’s Fa0/1 IP Address from R1 as shown below;
R1#ping 10.1.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.1.1.2, timeout is 2 seconds: .!!!! Success rate is 80 percent (4/5), round-trip min/avg/max = 1/2/4 ms R1#