Basics of VLACP and LACP

When deploying any data solution. It is always a good practice to review your switch capacity and functionality. From features provided with the running OS, hardware tweaks, to understanding where, and how your switch will be connected.

Sometime last year, I helped implement around 300 end-points for a township here in FL. The main building “City-hall” was handling the core switches connecting 5 other buildings through single mode fiber links, and across town we had configured a secondary recovery site for failover, using multimode fiber links connected back to City-hall.

I developed this list to help you understand the basics of  VLACP and LACP.

• Knowing your  Network Topology
• Best Practice
• VLACP and LACP
• Configuration examples

Knowing your Network Topology

Analyzing your customer’s data infrastructure to deliver an optimum product should always be your goal. One of those feature is the Link Aggregation Control Protocol, provided by the Avaya 3500s line of switches, and for Cisco this feature was introduce and implemented in the 10000 line of routers allowing the combination up to 4 gigabit Ethernet ports, to channel one 64 Gig port (running software version 12.2 (31)SB2.

Best Practice

For best practice we implemented VLACP in the Avaya 3500s Switches to allow for end-to-end failure detention between City-hall and the recovery site. You have to understand that while using Ethernet Networks has been extended to detect remote link failures through features such as Remote Fault Indication, and Far End Fault Indication mechanism. The limitations of these functions is to determine whenever there is a break in your topology, failing to monitor your data end to end, especially when your data leaves your LAN.

VLACP and LACP

VLACP is used whenever there is a router between your switches. For local IDFs connectivity you will configure LACP. Having the 802.ad Link Aggregation allows for combining two or more links together,  providing a great failover feature in case of a down link in your network. For some Cisco networks you will have to configure it in your router.

Configuration examples

Cisco LACP Redundancy Example=

• #config term
• #lacp system-priority 33000 (Remember that the standby priority port value will be lower)
• #interface range fastethernet 5/6 -7 (suppose that 5/6 priority is = 32768)
• #channel-protocol lacp
• #channel-group 1 mode active (Check both sides of your link)
• #interface fastethernet 5/6
• #lacp port-priority 33000
• #interface port-channel 1
• #lcap fast-switchover
• #lacp max-bundle 1
• #end

Avaya VLACP Example

• #lacp enable
• #vlacp macaddress 180.c200.f
• #vlacp hold_time 0
• #interface fastethernet all
• #vlacp port (ports) timeout short
• #vlacp port (ports) enable
• #exit

How about you, how do you configure your ports?. Active or passive?

Or what other methods do you normally use whenever configuring redundancy?