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ENHANCED LOAD BALANCING OF DATA TRAFFIC USING HSRP AS FIRST HOP GATEWAY PROTOCOL IN NORMAL STP CE CLOUD

IP.com Disclosure Number: IPCOM000235488D
Publication Date: 2014-Mar-04
Document File: 5 page(s) / 55K

Publishing Venue

The IP.com Prior Art Database

Related People

Rahul Mishra: AUTHOR

Abstract

Load sharing of data traffic with a reduced number of HSRP hello messages is achieved. This can be implemented by having two virtual IP addresses (VIPs) and two virtual media access control addresses (VMACs) per group instead of having one VIP and VMAC per group. VIP1/VMAC1 will be used by the active HSRP router for Address Resolution Protocol (ARP) replies and the source MAC (SMAC) of the HSRP hello message. VIP2/VMAC2 will be used by the standby HSRP router for ARP reply and SMAC of the HSRP hello message.

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ENHANCED LOAD BALANCING OF DATA TRAFFIC USING HSRP AS FIRST HOP GATEWAY PROTOCOL IN NORMAL STP CE CLOUD

AUTHOR:

Rahul Mishra

CISCO SYSTEMS, INC.

ABSTRACT

    Load sharing of data traffic with a reduced number of HSRP hello messages is achieved. This can be implemented by having two virtual IP addresses (VIPs) and two virtual media access control addresses (VMACs) per group instead of having one VIP and VMAC per group. VIP1/VMAC1 will be used by the active HSRP router for Address Resolution Protocol (ARP) replies and the source MAC (SMAC) of the HSRP hello message. VIP2/VMAC2 will be used by the standby HSRP router for ARP reply and SMAC of the HSRP hello message.

DETAILED DESCRIPTION

    The Hot-Standby Router Protocol (HSRP) is often used to improve resiliency in networks, but this can cause a decrease in network efficiency. With normal HSRP only one router that is active can forward traffic (can do a layer 3 lookup and route a packet). Multiple HSRP (MHSRP) was later developed, which uses two groups per interface.

    Techniques are presented herein in which only one HSRP group is needed for load sharing between two devices. The idea is to get traffic layer 3 forwarded from an active router as well as a standby router using a single HSRP group from one local area network (LAN) segment. With a single group, only one HSRP "hello" message will be sent on a LAN segment from the active router and one from the standby router. The same can be done with twice the number of groups but that requires more "hello" messages getting exchanged via the underlying LAN hence consuming more bandwidth as well as CPU usage (control plane processing by network stack as well as HSRP process). With two virtual MAC addresses (VMAC) and 2 virtual IP addresses (VIP) (both VIP/VMAC can be user configurable with a keyword indicating which to use on Copyright 2014 Cisco Systems, Inc.

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active and which to use on standby), one VMAC will be programmed on active to forward data traffic and the other VMAC will be programmed on standby to forward data traffic.

    The diagram below shows a typical datacenter topology having core, aggregation and access layers. Aggregation multilayer switches Agg1 and Agg2 would be running HSRP. The Aggregation to Core connection is layer 3. Thus, the core layer is completely layer 3 connected to two aggregation switches through a layer 3 link. Hosts h1 and h2 are connected to access switch Acc1 in same layer 2 domain. Access switch Acc1 is the access layer where host h1 and h2 will be connected using links in same VLAN. Access switch Acc1 is Access layer connected to the Aggregation layer through a layer 2 link to aggregation devices Agg1 and Agg2.

Agg1 Agg2

HSRP 1 HSRP 1

VIP1 vMAC1 x VIP1 VMAC1 x VIP2 VMAC2 VIP2 VMAC2

Copyright 2014 Cisco Systems, Inc.

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    In the above configuration, only HSRP 1 is used, which means there is only one group running with two VIPs and VMACs. Without this approach, two groups would be neede...