CISOC 2821 安装2个 HWIC-4ESW（就是4口以太网的模块）的问题

Question

CISOC 2821 原来有一个HWIC-4ESW（就是4口以太网的模块），工作正常。 关机，添加多一块HWIC-4ESW模块，用串口连接机器，可以看到正确检测到两块HWIC-4ESW。
启动完后，发现网络连接不正常，用控制台PING机器本身的IP地址，如vlan1的IP地址为10.10.10.254，该VLAN包括fast0/3/3接口，链接fast0/3/3的设备的IP地址为10.10.10.250，在控制台上ping 10.10.10.254正常，但ping 10.10.10.250不正常？
把新加的模块拆除后网络恢复正常，对调两个模块也工作正常。

请问是什么原因，需要怎么配置？

Answer 1

Prerequisites for Installing Two Ethernet Switch Network Modules in a Single Chassis:
A maximum of two Ethernet switch network modules can be installed in a single chassis. If two Ethernet switch network modules of any type are installed in the same chassis, the following configuration requirements must be met:
• Both Ethernet switch network modules must have an optional Gigabit Ethernet expansion board installed.
• An Ethernet crossover cable must be connected to the two Ethernet switch network modules using the optional Gigabit Ethernet expansion board ports.
• Intrachassis stacking for the optional Gigabit Ethernet expansion board ports must be configured.
Note: Without this configuration and connection, duplications will occur in the VLAN databases, and unexpected packet handling may occur.
参考：ttp://www.cisco.com/en/US/docs/ios/lanswitch/configuration/guide/lsw_hwic_ethsw_ic.pdf