第四章 PIM SSM实现域间组播.doc

第四章 pim ssm实现域间组播在网络中实现ssm有以下优点：1、 不需要管理组播地址2、 防止了不明的组播源服务的攻击3、 便于安装、管理4、 用于internet的广播应用（iptv）非常理想pim ssm默认情况下使用232.0.0.0/8的组播地址，路由器识别出是加入在这个范围内的组播组，均采用ssm的方式来运行。这个案例将会测试ssm的基本运行情况，ssm不再以来与rp来完成组播树的建设，因此在一个纯ipm ssm的环境下，不需要配置rp地址，启用ssm使用全局命令ip pim ssm default使用的拓扑如下：r1的具体配置hostname r1no ip domain lookupip multicast-routing interface loopback0 ip address 1.1.1.1 255.255.255.255interface serial1/0 ip address 12.1.1.1 255.255.255.0 ip pim sparse-modeclock rate 64000interface serial2/0 ip address 13.1.1.1 255.255.255.0 ip pim sparse-moderouter ospf 1 router-id 1.1.1.1network 0.0.0.0 255.255.255.255 area 0ip pim ssm default r2的具体配置hostname r2no ip domain lookupip multicast-routing interface loopback0 ip address 2.2.2.2 255.255.255.255interface ethernet0/0 ip address 10.1.1.2 255.255.255.0 ip pim sparse-modeinterface serial1/0 ip address 24.1.1.2 255.255.255.0 ip pim sparse-modeclock rate 64000interface serial2/0 ip address 12.1.1.2 255.255.255.0 ip pim sparse-moderouter ospf 1 router-id 2.2.2.2network 0.0.0.0 255.255.255.255 area 0ip pim ssm defaultr3的具体配置hostname r3no ip domain lookupip multicast-routing interface loopback0 ip address 3.3.3.3 255.255.255.255interface ethernet0/0 ip address 10.1.1.3 255.255.255.0 ip pim sparse-modeinterface serial1/0 ip address 13.1.1.3 255.255.255.0 ip pim sparse-modeclock rate 64000interface serial2/0 ip address 35.1.1.3 255.255.255.0 ip pim sparse-mode serial restart-delay 0router ospf 1 router-id 3.3.3.3network 0.0.0.0 255.255.255.255 area 0ip pim ssm defaultr4的具体配置hostname r4no ip domain lookupip multicast-routing interface loopback0 ip address 4.4.4.4 255.255.255.255interface serial2/0 ip address 24.1.1.4 255.255.255.0 ip pim sparse-moderouter ospf 1 router-id 4.4.4.4network 0.0.0.0 255.255.255.255 area 0ip pim ssm defaultr5的具体配置hostname r5no ip domain lookupip multicast-routing interface loopback0 ip address 5.5.5.5 255.255.255.255interface serial1/0 ip address 35.1.1.5 255.255.255.0 ip pim sparse-modeclock rate 64000router ospf 1 router-id 5.5.5.5network 0.0.0.0 255.255.255.255 area 0ip pim ssm default注意一点的就是：末节客户端主机支持igmpv3，即可加入到ssm网络中，如果不支持igmpv3，还有另外3种解决方案：1：igmpv3 lite主机信令，即在客户端安装一个程序库使之支持部分igmpv3（这一部分正是ssm所需要的）。2：urd主机信令，以来urp web服务器及cisco路由器在末跳（最接近客户位置）截获客户（s，g）信道订阅（同时客户端使用igmpv2加入组）。3：dns解析，ssm mapping 建立组播加入组和源的映射关系。（新版本ios似乎已经取消这个功能）。我们把r4作为一个支持igmpv3的客户端主机，加入到（5.5.5.5,232.1.1.1）这个源组里：ip igmp static-group 232.1.1.1 source 5.5.5.5r2# sh ip mrou ip multicast routing tableflags: d - dense, s - sparse, b - bidir group, s - ssm group, c - connected, l - local, p - pruned, r - rp-bit set, f - register flag, t - spt-bit set, j - join spt, m - msdp created entry, x - proxy join timer running, a - candidate for msdp advertisement, u - urd, i - received source specific host report, z - multicast tunnel, z - mdt-data group sender, y - joined mdt-data group, y - sending to mdt-data groupoutgoing interface flags: h - hardware switched, a - assert winner timers: uptime/expires interface state: interface, next-hop or vcd, state/mode(5.5.5.5, 232.1.1.1), 00:00:15/00:03:15, flags: st incoming interface: ethernet0/0, rpf nbr 10.1.1.3 outgoing interface list: serial1/0, forward/sparse, 00:00:15/00:03:15(*, 224.0.1.40), 00:33:07/stopped, rp 0.0.0.0, flags: dcl incoming interface: null, rpf nbr 0.0.0.0 outgoing interface list:serial1/0, forward/sparse, 00:33:07/00:00:52r3#sh ip mrou ip multicast routing tableflags: d - dense, s - sparse, b - bidir group, s - ssm group, c - connected, l - local, p - pruned, r - rp-bit set, f - register flag, t - spt-bit set, j - join spt, m - msdp created entry, x - proxy join timer running, a - candidate for msdp advertisement, u - urd, i - received source specific host report, z - multicast tunnel, z - mdt-data group sender, y - joined mdt-data group, y - sending to mdt-data groupoutgoing interface flags: h - hardware switched, a - assert winner timers: uptime/expires interface state: interface, next-hop or vcd, state/mode(5.5.5.5, 232.1.1.1), 00:00:22/00:03:08, flags: st incoming interface: serial2/0, rpf nbr 35.1.1.5 outgoing interface list: ethernet0/0, forward/sparse, 00:00:22/00:03:08(*, 224.0.1.40), 00:31:35/stopped, rp 0.0.0.0, flags: dcl incoming interface: null, rpf nbr 0.0.0.0 outgoing interface li