INE R&S ATC005 - VTP Prune Eligible List, VTP Transparent, VTP Troubleshooting, Trunk Allowed List, Extended VLANs

預設VLANs 2 –1001 are "prune eligible"
如何確認呢? show int fa0/2 switchport
會有一行Pruning VLANS Enable: 2-1001

VLANs not in the “prune eligible list” cannot be pruned
- i.e. traffic will always be sent/received for them

若於Trunk Port上設定
switchport trunk pruning vlan remove X
表示VLAN X就不在Prune eligible清單中(一定會被FWD)
can't be pruning -> 表示FWD

若網路中有一台Router/VM有Trunk(若不支援VTP)
會讓VTP Prune功能失效...全部VLAN FWD
解決方式: 在界接的SW Trunk Port上設定...switchport trunk allowed vlan X,Y,Z

若VTP Client(Switch) Revision為10
Disconnected Network
將SW VTP Client改為VTP Server--->ADD/Delete VLAN-->Revision若為12
將SW VTP Server改為VTP Client
Connected Network
全部網路的VLAN Database將會全部受影響.........真可怕.......
解決方式: VTP Transparent everywhere

VTP Transparent
VTP v1: VTP Domain Name & version 要相同才可以FWD VTP INFO
VTP v2: 即使VTP Domain Name 不同仍可以FWD VTP INFO
http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_46_se/configuration/guide/swvtp.html#wp1035121

當使用VTP Transparent時, 要特別小心...可能需要關閉VTP Pruning功能...

SW1自己為VTP Transparent.....也有VLAN 10.....這樣就會造成SW1與SW4的VLAN 10無法通訊
從SW4上會發現VLAN 10 STP在....但show interface pruning.........
解決方法: 於SW3關閉VTP Pruning功能......

Extended VLANs

- Normal VLAN range is 1 –1005
- Extended VLANs is range 1006 -4094
- Requires VTP Transparent mode