1066
OSPF Commands
Route Preferences
Normally, OSPF select routes in the following order:
• Local
• Static
• Intra-area
• Inter-area
• External
• RIP
PowerConnect OSPF allows the administrator to change the preference for
selecting intra, inter, and external routes according to the following rules:
a
External route preferences apply to all ospf external routes like type1,
type2, nssa-type1, nssa-type2 equally.
b
Multiple route types may be configured with equal preference values.
c
Configuring a route preference of 255 makes the route ineligible to be
selected as the best route to its destination. That is, a route type with
a preference of 255 shall never be used for forwarding.
The RIP preference is not used in IPv6 routing.
OSPF Equal Cost Multipath (ECMP)
A device running the IP routing protocol OSPF maintains multiple equal-cost
routes to all destinations. The multiple routes are of the same type (intra-
area, inter-area, type 1 external or type 2 external), cost, and have the same
associated area. However, each route is defined by a separate advertising
router and next hop.
With ECMP, a device forwards traffic to a specified destination through
multiple paths thereby taking advantage of the bandwidth of both links.
ECMP routes are configured statically or learned dynamically as follows:
• Configured Statically: If an operator configures multiple static routes to
the exact same destination but with different next hops, those routes are
treated as a single route with two next hops.
2CSPC4.XModular-SWUM200.book Page 1066 Thursday, March 10, 2011 11:18 AM
Summary of Contents for PowerEdge M420
Page 161: ...Command Groups 161 ...
Page 162: ...162 Command Groups ...
Page 216: ...216 Layer 2 Commands ...
Page 290: ...290 Auto VoIP Commands ...
Page 310: ...310 Data Center Bridging Commands ...
Page 316: ...316 DHCP Layer 2 Relay Commands Example console config dhcp l2relay vlan 10 340 345 ...
Page 324: ...324 DHCP Management Interface Commands ...
Page 340: ...340 DHCP Snooping Commands ...
Page 354: ...354 Dynamic ARP Inspection Commands ...
Page 405: ...Ethernet Configuration Commands 405 Name test ...
Page 406: ...406 Ethernet Configuration Commands ...
Page 426: ...426 Ethernet CFM Commands ...
Page 486: ...486 IPv6 Access List Commands ...
Page 497: ...IPv6 MLD Snooping Commands 497 Vlan Ipv6 Address Ports ...
Page 498: ...498 IPv6 MLD Snooping Commands ...
Page 512: ...512 IP Source Guard Commands ...
Page 524: ...524 iSCSI Optimization Commands ...
Page 532: ...532 Link Dependency Commands ...
Page 572: ...572 Port Aggregator Commands ...
Page 756: ...756 VLAN Commands ...
Page 762: ...762 Voice VLAN Commands ...
Page 796: ...796 802 1x Commands ...
Page 798: ...798 Layer 3 Commands ...
Page 842: ...842 DHCP Server and Relay Agent Commands ...
Page 868: ...868 DVMRP Commands ...
Page 888: ...888 IGMP Commands ...
Page 896: ...896 IGMP Proxy Commands ...
Page 938: ...938 IP Routing Commands ...
Page 1012: ...1012 IPv6 Routing Commands ...
Page 1016: ...1016 Loopback Interface Commands ...
Page 1048: ...1048 Multicast Commands ...
Page 1064: ...1064 IPv6 Multicast Commands RP Address 3001 1 origin BSR ...
Page 1142: ...1142 OSPF Commands ...
Page 1202: ...1202 OSPFv3 Commands ...
Page 1212: ...1212 Router Discovery Protocol Commands ...
Page 1228: ...1228 Routing Information Protocol Commands ...
Page 1260: ...1260 Virtual Router Redundancy Protocol Commands ...
Page 1262: ...1260 Utility Commands ...
Page 1272: ...1270 Auto Install Commands ...
Page 1306: ...1304 Captive Portal Commands ...
Page 1316: ...1314 CLI Macro Commands ...
Page 1334: ...1332 Clock Commands ...
Page 1340: ...1338 Command Line Configuration Scripting Commands ...
Page 1362: ...1360 Configuration and Image File Commands ...
Page 1363: ...Configuration and Image File Commands 1361 ...
Page 1364: ...1362 Configuration and Image File Commands ...
Page 1412: ...1408 Password Management Commands ...
Page 1436: ...1432 RMON Commands ...
Page 1476: ...1472 Sflow Commands ...
Page 1536: ...1532 Syslog Commands ...
Page 1602: ...1598 Telnet Server Commands ...
Page 1604: ...1600 Terminal Length Commands ...
Page 1618: ...1614 User Interface Commands ...
Page 1638: ...1634 Web Server Commands ...
Page 1680: ...1676 Appendix A List of Commands ...
Page 1681: ......
Page 1682: ...www dell com support dell com Printed in the U S A ...