cisco思科IOU/IOL不支持哪些特性？

思科的IOU/IOL是很强大，但它也并不是万能的，也有一些特性不支持，实验没法做。与GNS3想比，各有千秋吧。

综合网友们的调测意见，下面罗列了一些：

Not supported/working on Layer 3 IOL (Linux)

1. Multicast with BSR
2. NTP Authentication
3. PPPoE (working on 12.4, and 15.2(2.3)T)
4. Routing loops (IOL will crash)

Not supported/working on Layer 2 IOL (Linux)

1. 802.1q Tunneling
2. Cisco ISL trunks
3. DHCP Snooping
4. HSRP address not pingable
5. L2 PortChannel (not working on 12.2, working on 15.0)
6. L3 PortChannel
7. NVI NAT (classic NAT works on TPGEN images only)
8. PVLAN
9. QinQ
10. Routing loops (IOL will crash)
11. SPAN/RSPAN/ERSPAN
12. VTP version 2 (VTP version 1 works)

Not supported/working on Layer 3 IOU (Solaris)

1. VTP version 2 (VTP version 1 works)

Not supported/working on Layer 2 IOU (Solaris)

1. VTP version 2 (VTP version 1 works)