Executive Summary:

Our network was experiencing performance issues and a lack of redundancy due to a single point of failure in the connectivity between switches and servers. To address these issues, we implemented Link Aggregation Control Protocol (LACP) to aggregate multiple physical links into a single logical link. This approach improved network performance, increased bandwidth, and enhanced redundancy, thereby minimizing the risk of downtime caused by a single link failure.

Introduction:

The network topology in question consisted of several switches and servers connected using individual physical links. This setup led to performance bottlenecks and a lack of redundancy due to the reliance on single links for connectivity. To address these issues, we proposed implementing LACP, an IEEE 802.3ad standard, to aggregate multiple physical links between switches and servers, creating a single logical link with higher bandwidth and improved redundancy.

Implementation Steps:

1. Identifying appropriate links for aggregation: We analyzed the existing network topology and selected appropriate links between switches and servers that could be aggregated to form logical links. This included ensuring that the links had the same speed and duplex settings.
2. Configuring LACP on switches: We configured LACP on the switches by creating Link Aggregation Groups (LAGs) and assigning the selected physical links to the LAGs. The configuration on Cisco switches involved the following steps:

interface range GigabitEthernet 0/1-2
channel-group 1 mode active

For Arista switches, the configuration was similar:

interface Ethernet 1-2
channel-group 1 mode active

3. Configuring LACP on servers: We configured LACP on the servers by creating LAGs and assigning the selected physical links to the LAGs. The configuration varied depending on the server operating system. For Linux servers, we used the ifenslave package to configure bonding:

auto bond0
iface bond0 inet static
address 192.168.1.10
netmask 255.255.255.0
gateway 192.168.1.1
bond-mode 802.3ad
bond-miimon 100
bond-lacp-rate 1
bond-slaves eth0 eth1

For Windows servers, we used the built-in NIC Teaming feature to create LACP teaming.

4. Verifying the proper operation of the aggregated links: We verified the LACP configuration on switches and servers, ensuring that the LAGs were active and operational. On Cisco and Arista switches, we used the show etherchannel summary and show lacp commands to verify the LAG status.

show etherchannel summary
show lacp

On Linux and Windows servers, we checked the bonding status using the appropriate tools, such as /proc/net/bonding/bond0 for Linux and the NIC Teaming UI for Windows.

Outcome:

After implementing LACP and aggregating the selected links, we observed improved network performance, increased bandwidth, and enhanced redundancy. The risk of downtime caused by a single link failure was minimized due to the availability of multiple links in the LAGs. This implementation allowed the network to better handle traffic loads and provided a more resilient infrastructure, ensuring seamless connectivity between switches and servers.