二级网络改造实施方案1．改造前网络结构图..................................................................................................22．改造步骤简述..........................................................................................................33．中心端局域网部分..................................................................................................33.1方案一：双系统在线模式...............................................................................43.1.1改造前局域网结构.................................................................................43.1.2改造期间局域网结构.............................................................................53.1.2.1结构模式1....................................................................................53.1.2.2结构模式2....................................................................................73.1.2.3结构模式3....................................................................................83.1.3改造后局域网结构.................................................................................93.2方案二：依次替换每台Cisco7505...............................................................103.2.1切换步骤...............................................................................................103.2.2局域网端口连接表...............................................................................113.2.3局域网连线图.......................................................................................123.2.4路由器HSRP组...................................................................................133.3方案三：同时替换两台Cisco7505...............................................................144．广域网部分............................................................................................................144.1关于SPA-2XOC3-ATM模块.........................................................................144.2中心端ATM模块的配置...............................................................................157606配置举例...............................................................................................164.3二级网骨干路由器改造前后接口对应表.....................................................185．分行改造部分........................................................................................................215.1改造步骤.........................................................................................................215.2Cisco3725路由器接口示意图......................................................................235.3Cisco3825路由器接口示意图......................................................................246．分行改造结束后部分............................................................................................257．回退步骤................................................................................................................257.1省分行部分.....................................................................................................257.1.1情况1：多于2个的分行无法完成切换.............................................257.1.2情况2：2个以内的分行无法完成切换.............................................267.2辖属分行局域网部分.....................................................................................268．测试方案..................
