Chapter 31: Virtual Router Redundancy Protocol
368
Section VII: Routing
VRRP on the Switch
VRRP is disabled by default. When a virtual router is created on the
switch, it is enabled by default, but the VRRP module must be enabled
before it is operational. The VRRP module or a specific virtual router can
be enabled or disabled afterwards by using the ENABLE VRRP and
DISABLE VRRP commands.
A virtual router must be created on at least two switches before it operates
correctly. To create a virtual router for an IP address over an Ethernet
interface, so that the switch participates in the virtual router, use the
CREATE VRRP command.
To destroy a virtual router on the LAN, it must be removed from all
participating switches. To remove a virtual router so that the switch no
longer participates in it, use the DESTROY VRRP command.
If the switch in the master role for the virtual router becomes unavailable,
the master role is taken by the switch with the highest priority
amongst the
available switches. The priority is a value from 1 to 255, with a default of
100. The highest value of 255 is reserved for the switch that owns the
virtual router’s IP address. The new master takes over all the
responsibilities of the original master. Hosts on the LAN can continue
sending packets to the same virtual MAC address with which they
associate the configured first hop IP address, even though the switch that
owns the IP address is not currently available. When the preferred switch
that owns the IP address becomes available again, it resumes the role of
master.
By default, when a switch becomes available with a higher priority than the
master, it takes over as master. This is referred to as
preempt
mode and
can be set on or off. Even with preempt mode off, the switch that owns the
IP address always becomes the master when available. If two switches
are configured with the same priority, the one with the highest IP address
has higher priority. Preempt mode must be the same for all switches in the
virtual router. Set the priority and preempt mode when you create the
virtual router; modify it later by using the SET VRRP command.
The frequency with which the master sends advertisement packets must
be set to the same value for all switches in the virtual router. The default
advertisement interval of 1 second is recommended for most networks.
This is set with the ADINTERVAL parameter in the CREATE VRRP and
SET VRRP commands.
Each of the switches in the virtual router can be configured for plaintext
authentication or none. No authentication is suitable when there is minimal
security risk, and the configuration is so simple (for example, two switches
on a LAN) that there is little chance of configuration errors. Plaintext
password authentication protects against accidental misconfiguration and
Содержание AT-S63
Страница 14: ...Figures 14 ...
Страница 18: ...Tables 18 ...
Страница 28: ...28 Section I Basic Operations ...
Страница 58: ...Chapter 1 Overview 58 ...
Страница 76: ...Chapter 2 AT 9400Ts Stacks 76 Section I Basic Operations ...
Страница 96: ...Chapter 5 MAC Address Table 96 Section I Basic Operations ...
Страница 114: ...Chapter 8 Port Mirror 114 Section I Basic Operations ...
Страница 116: ...116 Section II Advanced Operations ...
Страница 146: ...Chapter 12 Access Control Lists 146 Section II Advanced Operations ...
Страница 176: ...Chapter 14 Quality of Service 176 Section II Advanced Operations ...
Страница 196: ...196 Section III Snooping Protocols ...
Страница 204: ...Chapter 18 Multicast Listener Discovery Snooping 204 Section III Snooping Protocols ...
Страница 216: ...Chapter 20 Ethernet Protection Switching Ring Snooping 216 Section III Snooping Protocols ...
Страница 218: ...218 Section IV SNMPv3 ...
Страница 234: ...234 Section V Spanning Tree Protocols ...
Страница 268: ...268 Section VI Virtual LANs ...
Страница 306: ...Chapter 27 Protected Ports VLANs 306 Section VI Virtual LANs ...
Страница 320: ...320 Section VII Internet Protocol Routing ...
Страница 360: ...Chapter 30 BOOTP Relay Agent 360 Section VII Routing ...
Страница 370: ...Chapter 31 Virtual Router Redundancy Protocol 370 Section VII Routing ...
Страница 372: ...372 Section VIII Port Security ...
Страница 402: ...Chapter 33 802 1x Port based Network Access Control 402 Section VIII Port Security ...
Страница 404: ...404 Section IX Management Security ...
Страница 436: ...Chapter 36 PKI Certificates and SSL 436 Section IX Management Security ...
Страница 454: ...Chapter 38 TACACS and RADIUS Protocols 454 Section IX Management Security ...
Страница 462: ...Chapter 39 Management Access Control List 462 Section IX Management Security ...
Страница 504: ...Appendix B SNMPv3 Configuration Examples 504 Security Model Security Level Storage Type SNMPv3 Parameters Continued ...
Страница 532: ...Appendix D MIB Objects 532 ...