© 2006 Cisco Systems, Inc. All rights reserved. BCMSN v3.05-1 Implementing High Availability in a Campus Environment Optimizing HSRP. - презентация

1 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Implementing High Availability in a Campus Environment Optimizing HSRP

2 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v HSRP Optimization Options These options can be configured to optimize HSRP: HSRP standby priority HSRP standby preempt Hello message timers HSRP interface tracking

3 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Configuring HSRP Standby Priority The router with the highest priority in an HSRP group becomes the active router. The default priority is 100. In the case of a tie, the router with the highest configured IP address will become active.

4 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Configuring HSRP Standby Preempt Preempt enables a router to resume the forwarding router role.

5 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Configuring the Hello Message Timers The holdtime parameter value should be at least three times the value of the hellotime parameter.

6 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v HSRP Interface Tracking

7 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v HSRP Interface Tracking (Cont.)

8 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Configuring HSRP Tracking Switch(config-if)#standby [group-number] track type number [interface-priority] Configures HSRP tracking Switch(config)#interface vlan 10 Switch(config-if)#standby 1 track GigabitEthernet 0/7 50 Switch(config-if)#standby 1 track GigabitEthernet 0/8 60 Example of HSRP tracking Note: Preempt must be configured on all participating devices within the HSRP group.

9 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Tuning HSRP Configure hellotime and holdtime to millisecond values. Configure preempt delay timer so that preempt occurs only after the distribution switch has fully rebooted and established full connectivity to the rest of the network.

10 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v To load balance routers, assign them to multiple groups on the same subnet. Multiple HSRP Groups

11 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Addressing HSRP Groups Across Trunk Links To load balance routers and links: –Per VLAN, configure the HSRP active router and the spanning tree root to be the same multilayer switch.

12 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v About the HSRP Debug Command debug standby events debug standby terse

13 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Debugging HSRP Example of HSRP debug showing standby group number mismatch DSW111#debug standby *Mar 4 19:08:08.918: HSRP: Vl1 Grp 1 Hello out Active pri 150 vIP *Mar 4 19:08:09.287: HSRP: Vl1 Grp 2 Hello in Active pri 50 vIP *Mar 4 19:08:09.287: HSRP: Vl1 API active virtual address found *Mar 4 19:08:09.891: HSRP: Vl1 API Duplicate ARP entry detected for *Mar 4 19:08:09.891: HSRP: Vl1 Grp 1 Hello out Active pri 150 vIP *Mar 4 19:08:10.294: HSRP: Vl1 Grp 2 Hello in Active pri 50 vIP *Mar 4 19:08:10.294: HSRP: Vl1 API active virtual address found *Mar 4 19:08:10.294: HSRP: Vl1 API Duplicate ARP entry detected for *Mar 4 19:08:10.294: HSRP: Vl1 Grp 1 Hello out Active pri 150 vIP *Mar 4 19:08:10.294: HSRP: Vl1 Grp 2 Hello in Active pri 50 vIP *Mar 4 19:08:10.294: HSRP: Vl1 API active virtual address found *Mar 4 19:08:10.898: HSRP: Vl1 API Duplicate ARP entry detected for *Mar 4 19:08:10.898: HSRP: Vl1 Grp 1 Hello out Active pri 150 vIP *Mar 4 19:08:10.965: HSRP: Vl1 Grp 2 Hello in Active pri 50 vIP *Mar 4 19:08:11.300: HSRP: Vl1 API active virtual address found

14 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v Summary Preempt, timers, and interface tracking are options that can be configured to optimize HSRP. HSRP preempt can be tuned by adjusting timers that can thereby reduce failover time. To facilitate load sharing, a single interface on a router can be a member of multiple HSRP groups. Specific debug commands are used to view HSRP state changes. Debug can be used to discover the virtual IP address and the priority of the active and standby routers.

15 © 2006 Cisco Systems, Inc. All rights reserved. BCMSN v