Gateway Load Balancing Protocol (GLBP) provides redundancy for IP systems, making certain that user traffic immediately and transparently rebounds from first hop router failures, while permitting packet load discussing between several redundant hubs. GLBP provides load balancing over multiple hubs (gateways) utilizing a single virtual Ip and multiple virtual MAC addresses. Each host is set up with similar virtual Ip, and all sorts of hubs within the virtual router group take part in sending packets. GLBP people communicate between one another through hello messages sent every 3 seconds towards the multicast address 224…102, User Datagram Protocol (UDP) port 3222 (source and destination).
This selection was built-into ‘cisco’ IOS Software Release 12.2(15) T. Use ‘cisco’ Feature Navigator to obtain the latest details about platform support and ‘cisco’ IOS Software image support.
Before setting up the GLBP feature, be sure that the hubs supports multiple MAC addresses around the physical connects. Several Ethernet (LANCE and QUICC) remotes in low-finish items are only able to possess a single unicast MAC address within their address filter. To ensure this, problem the show connects command, and be sure that the displayed hardware is neither LANCE nor QUICC. These remotes don’t support association of multiple MAC addresses using the interface.
Configuration Example: GLBP works by utilizing just one virtual Ip, that is set up because the default gateway around the hosts. The various hubs that assume the sending role use different virtual MAC addresses for the similar virtual Ip that packets are submitted through the hosts.
The next sample configuration creates two hubs R1 and R2 as GLBP, gateways serving the 172.16.1. network with 172.16.1.1 because the virtual gateway address.This is actually the default gateway that might be set up on all of the hosts within the 172.16.1. network. The configuration could be: R1(config)#interface vlan110 R1(config-if)#ip 172.16.1.10 255.255.255. R1(config-if)#glbp 1 ip 172.16.1.1 R1(config-if)#glbp 1 preempt R1(config-if)#glbp 1 priority 150 R2(config)#interface vlan110 R2(config-if)#ip 172.16.1.11 255.255.255. R2(config-if)#glbp 1 ip 172.16.1.1
Other helpful instructions could be: glbp authentication= The authentication string is distributed in plain text in most GLBP messages. Exactly the same authentication string should be set up on all of the hubs which are set up to become people of the identical GLBP group, to make sure interoperation. A router will ignore all GLBP messages which contain the incorrect authentication string. glbp forwarder preempt=Utilize to configure a router to consider over as AVF for any GLBP group whether it has greater priority compared to current AVFRouter to consider over as AVF for any GLBP group whether it has greater priority compared to current AVF glbp timer= Time between hello packets sent through the GLBP gateway and also the time the virtual gateway and virtual forwarder details are considered valid. glbp timers redirect=Time throughout that the AVG for any GLBP group is constantly on the redirect clients to some secondary active virtual forwarder (AVF), glbp weighting=To specify the first weighting worth of the GLBP gateway, glbp weighting track=Using the “glbp weighting track” and “track object-number interface type number ” instructions to configure parameters to have an interface to become monitored. If the interface on the router goes lower, the weighting for that router could be reduced with a specified value.
Verifying GLBP: CommandsExplaination
Router# show glbpDisplays GLBP information Router# show glbp brief Shows a short status of GLBP groups Router# show glbp 1 Shows details about GLBP group 1 Router# show glbp fastethernet /0Displays GLBP info on interface fastethernet / Router# show glbp fastethernet / 1Displays GLBP group 1 info on interface fastethernet / Debugging GLBP: Instructions Explaination
Router# debug condition glbp Shows GLBP condition messages Router# debug glbp errorsDisplays all GLBP error messages Router# debug glbp eventsDisplays all GLBP event messages Router# debug glbp packetsDisplays messages about packets sent and received A document from ‘cisco’ Support Community was produced by TCC and modified by Ashish Shirkar. Original assets from —
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