Configuration Guide User guide

FastIron Configuration Guide xxxiii
53-1002494-02
Optional BGP4 configuration tasks . . . . . . . . . . . . . . . . . . . . . . . 1365
Changing the Keep Alive Time and Hold Time . . . . . . . . . . . 1365
Changing the BGP4 next-hop update timer . . . . . . . . . . . . . 1365
Enabling fast external fallover. . . . . . . . . . . . . . . . . . . . . . . . 1366
Changing the maximum number of paths for
BGP4 load sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1366
Customizing BGP4 load sharing . . . . . . . . . . . . . . . . . . . . . . 1368
Specifying a list of networks to advertise. . . . . . . . . . . . . . . 1368
Changing the default local preference . . . . . . . . . . . . . . . . . 1370
Using the IP default route as a valid next hop for
a BGP4 route . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1370
Advertising the default route. . . . . . . . . . . . . . . . . . . . . . . . . .1371
Changing the default MED (Metric) used for
route redistribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1371
Enabling next-hop recursion . . . . . . . . . . . . . . . . . . . . . . . . . .1371
Changing administrative distances . . . . . . . . . . . . . . . . . . . .1374
Requiring the first AS to be the neighbor AS . . . . . . . . . . . . .1376
Disabling or re-enabling comparison of the
AS-Path length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1376
Enabling or disabling comparison of the router IDs . . . . . . .1376
Configuring the Layer 3 switch to always compare
Multi-Exit Discriminators (MEDs) . . . . . . . . . . . . . . . . . . . . . .1377
Treating missing MEDs as the worst MEDs . . . . . . . . . . . . . .1377
Route reflection parameter configuration . . . . . . . . . . . . . . 1378
Configuration notes for BGP4 autonomous systems . . . . . 1381
Aggregating routes advertised to BGP4 neighbors . . . . . . . 1384
Configuring BGP4 graceful restart . . . . . . . . . . . . . . . . . . . . . . . . 1385
Configuring BGP4 graceful restart . . . . . . . . . . . . . . . . . . . . 1385
Configuring timers for BGP4 graceful restart (optional) . . . 1385
BGP null0 routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1386
Configuration steps for BGP null 0 routing. . . . . . . . . . . . . . 1387
Configuration examples for BGP null 0 routing . . . . . . . . . . 1388
Show commands for BGP null 0 routing. . . . . . . . . . . . . . . . 1389
Modifying redistribution parameters . . . . . . . . . . . . . . . . . . . . . . 1391
Redistributing connected routes. . . . . . . . . . . . . . . . . . . . . . 1391
Redistributing RIP routes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1392
Redistributing OSPF external routes. . . . . . . . . . . . . . . . . . . 1392
Redistributing static routes . . . . . . . . . . . . . . . . . . . . . . . . . . 1393
Disabling or re-enabling re-advertisement of all learned
BGP4 routes to all BGP4 neighbors . . . . . . . . . . . . . . . . . . . 1393
Redistributing IBGP routes into RIP and OSPF. . . . . . . . . . . 1393
Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1394
Specific IP address filtering. . . . . . . . . . . . . . . . . . . . . . . . . . 1394
AS-path filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1395
BGP4 filtering communities . . . . . . . . . . . . . . . . . . . . . . . . . 1399
Defining IP prefix lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1401
Defining neighbor distribute lists . . . . . . . . . . . . . . . . . . . . . 1402
Defining route maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1403
Using a table map to set the rag value. . . . . . . . . . . . . . . . . .1411
Configuring cooperative BGP4 route filtering. . . . . . . . . . . . .1411