Public AS number is 1-64511
Private autonomous system (AS) numbers which range from 64512 to 65535 are used to conserve globally unique AS numbers.
from:http://www.cisco.com/warp/public/459/32.html
Shutdown neighbor command
router(config-router)#neighbor ip-address shutdown
錯誤訊息：
5w0d: %TCP-6-BADAUTH: Invalid MD5 digest from 10.15.96.250(31190) to 10.15.96.249(179)
A：二邊password 不對
大段的Route對方沒有收到，改切小段才行，原本放/20，但不知是否末段被用了，才不行
改切成 /21 /22 /23 /24 切完後debug ip bgp update event所得到的訊息
router_35#
6d11h: %SYS-5-CONFIG_I: Configured from console by vty0 (xxx.xxx.xxx.xxx)
6d11h: BGP(0): route xxx.xxx.32.0/21 up
6d11h: BGP(0): Increasing convergence goal from 4 to 5
6d11h: BGP(0): Reset update-group 1 versions from 4 to (cand xxx.xxx.xxx.141) 4
6d11h: BGP(0): nettable_walker xxx.xxx.32.0/21 route sourced locally
6d11h: BGP(0): Begin update run for versions 5->5 for 1 update groups
6d11h: BGP(0): update-group 1 leader is xxx.xxx.xxx.141
6d11h: BGP(0): xxx.xxx.xxx.141 send UPDATE (format) xxx.xxx.32.0/21, next xxx.xxx.xxx.142, metric 0, path
6d11h: BGP(0): updgrp 1 – xxx.xxx.xxx.141 enqueued 1 updates, average/maximum size (bytes) 52/52
6d11h: BGP(0): End update run for versions 5->5 (0ms), 1/1/0 updates formatted/enqueued/replicated, formatting was not aborted, enqueuing was not aborted, 1 attrs – 1 nets visited