Establish a Session................................................................................................................................................... 165Route Reflectors.............................................................................................................................................................166BGP Attributes................................................................................................................................................................167Best Path Selection Criteria.................................................................................................................................... 167Weight........................................................................................................................................................................169Local Preference.......................................................................................................................................................169Multi-Exit Discriminators (MEDs)...........................................................................................................................170Origin...........................................................................................................................................................................171AS Path...................................................................................................................................................................... 172Next Hop................................................................................................................................................................... 172Multiprotocol BGP.......................................................................................................................................................... 172Implement BGP with Dell Networking OS................................................................................................................... 173Additional Path (Add-Path) Support...................................................................................................................... 173Advertise IGP Cost as MED for Redistributed Routes.........................................................................................173Ignore Router-ID in Best-Path Calculation.............................................................................................................174Four-Byte AS Numbers............................................................................................................................................ 174AS4 Number Representation...................................................................................................................................174AS Number Migration...............................................................................................................................................176BGP4 Management Information Base (MIB)........................................................................................................ 177Important Points to Remember...............................................................................................................................177Configuration Information..............................................................................................................................................178BGP Configuration..........................................................................................................................................................178Enabling BGP............................................................................................................................................................ 179Configuring AS4 Number Representations........................................................................................................... 182Configuring Peer Groups......................................................................................................................................... 184Configuring BGP Fast Fall-Over.............................................................................................................................186Configuring Passive Peering................................................................................................................................... 188Maintaining Existing AS Numbers During an AS Migration................................................................................. 188Allowing an AS Number to Appear in its Own AS Path....................................................................................... 189Enabling Graceful Restart....................................................................................................................................... 190Enabling Neighbor Graceful Restart....................................................................................................................... 191Filtering on an AS-Path Attribute............................................................................................................................ 191Regular Expressions as Filters.................................................................................................................................193Redistributing Routes...............................................................................................................................................194Enabling Additional Paths........................................................................................................................................ 195Configuring IP Community Lists.............................................................................................................................195Configuring an IP Extended Community List........................................................................................................196Filtering Routes with Community Lists.................................................................................................................. 197Manipulating the COMMUNITY Attribute.............................................................................................................198Changing MED Attributes....................................................................................................................................... 199Changing the LOCAL_PREFERENCE Attribute.................................................................................................. 199Configuring the local System or a Different System to be the Next Hop for BGP-Learned Routes............ 200Changing the WEIGHT Attribute............................................................................................................................201Enabling Multipath....................................................................................................................................................201Filtering BGP Routes................................................................................................................................................201Contents 7
