Chapter 7: LACP Port Trunks
106
Section I: Basic Operations
LACP System Priority
It is possible for two devices interconnected by an aggregate trunk to
encounter a conflict when they form the trunk. For example, the two
devices might not support the same number of active ports in an
aggregate trunk or might not agree on which ports are to be active and
which are to be in standby.
If a conflict does occur, the two devices need a mechanism for resolving
the problem and deciding whose LACP settings are to take precedence.
This is the function of the system LACP priority value. A hexadecimal
value of from 1 to FFFF, this parameter is used whenever the devices
encounter a conflict creating a trunk. The lower the number, the higher the
priority. The settings on the device with the higher priority take precedence
over the settings on the other device. If both devices have the same
system LACP priority value, the settings on the switch with the lowest
MAC address take precedence.
This parameter can prove useful when connecting an aggregate trunk
between the AT-9400 Switch and another 802.3ad-compliant device that
does not have the same LACP trunking capabilities. If the other device’s
capability is less than that of the AT-9400 Switch, you should give that
device the higher priority so its settings are used by both devices when
forming the trunk.
For example, an aggregate trunk of six links between an AT-9400 Switch
and an 802.3ad-compliant device that supported up to four active links at
one time could possibly result in a conflict. The AT-9400 Switch would try
to use all six links as active, because it can handle up to eight active links
in a trunk at one time, while the other device would want to use only four
ports as active. By giving the other 802.3ad device the higher priority, the
conflict is avoided because the AT-9400 Switch would use only four active
links, as directed by the other 802.3ad-compliant device. The other ports
would remain in the standby mode.
Summary of Contents for AT-S63
Page 14: ...Figures 14 ...
Page 18: ...Tables 18 ...
Page 28: ...28 Section I Basic Operations ...
Page 58: ...Chapter 1 Overview 58 ...
Page 76: ...Chapter 2 AT 9400Ts Stacks 76 Section I Basic Operations ...
Page 96: ...Chapter 5 MAC Address Table 96 Section I Basic Operations ...
Page 114: ...Chapter 8 Port Mirror 114 Section I Basic Operations ...
Page 116: ...116 Section II Advanced Operations ...
Page 146: ...Chapter 12 Access Control Lists 146 Section II Advanced Operations ...
Page 176: ...Chapter 14 Quality of Service 176 Section II Advanced Operations ...
Page 196: ...196 Section III Snooping Protocols ...
Page 204: ...Chapter 18 Multicast Listener Discovery Snooping 204 Section III Snooping Protocols ...
Page 216: ...Chapter 20 Ethernet Protection Switching Ring Snooping 216 Section III Snooping Protocols ...
Page 218: ...218 Section IV SNMPv3 ...
Page 234: ...234 Section V Spanning Tree Protocols ...
Page 268: ...268 Section VI Virtual LANs ...
Page 306: ...Chapter 27 Protected Ports VLANs 306 Section VI Virtual LANs ...
Page 320: ...320 Section VII Internet Protocol Routing ...
Page 360: ...Chapter 30 BOOTP Relay Agent 360 Section VII Routing ...
Page 370: ...Chapter 31 Virtual Router Redundancy Protocol 370 Section VII Routing ...
Page 372: ...372 Section VIII Port Security ...
Page 402: ...Chapter 33 802 1x Port based Network Access Control 402 Section VIII Port Security ...
Page 404: ...404 Section IX Management Security ...
Page 436: ...Chapter 36 PKI Certificates and SSL 436 Section IX Management Security ...
Page 454: ...Chapter 38 TACACS and RADIUS Protocols 454 Section IX Management Security ...
Page 462: ...Chapter 39 Management Access Control List 462 Section IX Management Security ...
Page 532: ...Appendix D MIB Objects 532 ...