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TOPO

组播源PC1

定时发送i am the xxth message to 239.255.255.249 到组播组239.255.255.249

配置RouterB

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# root @ routerB in / [15:15:39]
$ iptables -t nat -D POSTROUTING 1 #关闭NAT，清空nat表

# root @ routerB in / [15:15:42]
$ iptables -t nat -nvL  # 查看nat表已清空
Chain PREROUTING (policy ACCEPT 8 packets, 569 bytes)
 pkts bytes target     prot opt in     out     source               destination

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

# root @ routerB in / [15:51:02]
$ ip link set eth0 multicast off  # 关闭eth0的组播功能，确保组播走的是gre隧道

# root @ routerB in / [15:51:17]
$ ip link set eth1 multicast off  # 关闭eth1的组播功能，确保组播走的是gre隧道

# root @ routerB in / [15:51:23]
$ ip addr show eth0  # 看到 <> 内已经没了MULTICAST
2: eth0: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:e2:69:24:0b:30 brd ff:ff:ff:ff:ff:ff
    inet 20.1.1.2/24 brd 20.1.1.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::2e2:69ff:fe24:b30/64 scope link
       valid_lft forever preferred_lft forever

# root @ routerB in / [16:18:55]
$ ip addr show eth1  # 看到 <> 内已经没了MULTICAST
3: eth1: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:e2:69:24:0b:31 brd ff:ff:ff:ff:ff:ff
    inet 30.1.1.1/24 brd 30.1.1.255 scope global eth1
       valid_lft forever preferred_lft forever
    inet6 fe80::2e2:69ff:fe24:b31/64 scope link
       valid_lft forever preferred_lft forever

# root @ routerB in / [16:50:09]
$ cat /etc/quagga/ospfd.conf  # 配置ospf
hostname Router_B
password testpassword
enable password testpassword
router ospf
	ospf router-id 20.1.1.2
	network 30.1.1.0/24 area 0
	network 20.1.1.0/24 area 0
debug ospf event
log file /usr/local/etc/ospfd.log

# root @ routerB in / [16:50:14]
$ systemctl restart quagga.service  # 重启quagg(ospf)

# root @ routerB in / [17:00:36]
$ ip r  # 查看路由表
20.1.1.0/24 dev eth0  proto kernel  scope link  src 20.1.1.2
30.1.1.0/24 dev eth1  proto kernel  scope link  src 30.1.1.1

配置gre

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#routerA
remoteip=30.1.1.2
localip=20.1.1.1
greip=10.10.10.1
grepeerip=10.10.10.2
grename=gre1
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#routerC
remoteip=20.1.1.1
localip=30.1.1.2
greip=10.10.10.2
grepeerip=10.10.10.1
grename=gre1
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#routerA and routerC
lsmod|grep ip_gre || modprobe ip_gre
#ping -c1 ${remoteip} || { echo "make sure the network is ok plz"; exit 1; }
ip addr show ${grename} && { echo "${grename} is already exist"; exit 1; }

ip tunnel add ${grename} mode gre remote ${remoteip} local ${localip} ikey 1 okey 1 ttl 255;
ip addr add ${greip} dev ${grename} peer ${grepeerip};
ip link set ${grename} multicast on up; #mtu 1400; # 注意一定要multicast on
ip addr show ${grename};

查看gre隧道接口

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# root @ routerA in / [16:53:20]
$ ip addr show gre1
7: gre1@NONE: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1472 qdisc noqueue state UNKNOWN group default qlen 1
    link/gre 20.1.1.1 peer 30.1.1.2
    inet 10.10.10.1 peer 10.10.10.2/32 scope global gre1
       valid_lft forever preferred_lft forever
    inet6 fe80::200:5efe:1401:101/64 scope link
       valid_lft forever preferred_lft forever
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# root @ routerC in / [16:54:38]
$ ip addr show gre1
16: gre1@NONE: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1472 qdisc noqueue state UNKNOWN group default qlen 1
    link/gre 30.1.1.2 peer 20.1.1.1
    inet 10.10.10.2 peer 10.10.10.1/32 scope global gre1
       valid_lft forever preferred_lft forever
    inet6 fe80::200:5efe:1e01:102/64 scope link
       valid_lft forever preferred_lft forever

测试隧道连接

routerA ping -I 10.10.10.1 10.10.10.2 -c2 通路
routerC ping -I 10.10.10.2 10.10.10.1 -c2 通路

配置router A和C的ospf

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# root @ routerA in / [16:56:48]
$ cat /etc/quagga/ospfd.conf
hostname Router_A
password testpassword
enable password testpassword
router ospf
	ospf router-id 10.10.10.1  # 这里用gre隧道的ip
	network 10.1.1.0/24 area 0
	network 10.10.10.0/24 area 0  # 使用隧道的网段
debug ospf event
log file /usr/local/etc/ospfd.log

# root @ routerA in / [17:05:03]
$ systemctl restart quagga.service
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# root @ routerC in / [17:06:07]
$ cat /etc/quagga/ospfd.conf
hostname Router_C
password testpassword
enable password testpassword
router ospf
    ospf router-id 10.10.10.2  # 这里用gre隧道的ip
    network 10.2.1.0/24 area 0
    network 10.10.10.0/24 area 0  # 使用隧道的网段
debug ospf event
log file /usr/local/etc/ospfd.log

# root @ routerC in / [17:06:19]
$ systemctl restart quagga.service

查看ospf生成的路由

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# root @ routerA in / [17:05:10]
$ ip r
default via 20.1.1.2 dev eth1
10.1.1.0/24 dev eth0  proto kernel  scope link  src 10.1.1.1
10.2.1.0/24 via 10.10.10.2 dev gre1  proto zebra  metric 20  # 这条由zebra生成的就是
10.10.10.2 dev gre1  proto kernel  scope link  src 10.10.10.1
20.1.1.0/24 dev eth1  proto kernel  scope link  src 20.1.1.1
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# root @ routerC in / [17:06:24]
$ ip r
default via 30.1.1.1 dev eth1
10.1.1.0/24 via 10.10.10.1 dev gre1  proto zebra  metric 20  # 这条由zebra生成的就是
10.2.1.0/24 dev eth0  proto kernel  scope link  src 10.2.1.1
10.10.10.1 dev gre1  proto kernel  scope link  src 10.10.10.2
30.1.1.0/24 dev eth1  proto kernel  scope link  src 30.1.1.2
192.168.255.0/24 dev eth3  proto kernel  scope link  src 192.168.255.1
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# root @ routerB in / [17:00:38]
$ ip r  # routerB确实没有获取到gre相关路由
20.1.1.0/24 dev eth0  proto kernel  scope link  src 20.1.1.2
30.1.1.0/24 dev eth1  proto kernel  scope link  src 30.1.1.1

测试ospf路由通路

PC1 ping 10.2.1.2 通路
PC2 ping 10.1.1.2 通路

配置pimd

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# root @ routerA in / [17:09:14]
$ diff -rauN /etc/pimd.conf.bak /etc/pimd.conf
--- /etc/pimd.conf.bak	2021-10-18 16:43:11.313255253 +0800
+++ /etc/pimd.conf	2021-10-19 15:41:13.738745717 +0800
@@ -132,7 +132,7 @@
 #group-prefix 224.0.0.0 masklen 4

 # Static rendez-vous point
-#rp-address 192.168.10.1 224.0.0.0/4  # 自选举方式
+rp-address 10.10.10.1 224.0.0.0/4  # 自选举太慢，手动指定汇聚点(这里用gre接口ip,也可用routerA的eth0的ip 10.1.1.1)

 # Switch to shortest-path tree after first packet, but only after 100 sec.
 spt-threshold packets 0 interval 100

# root @ routerA in / [17:20:01]
$ systemctl restart pimd.service
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# root @ routerC in / [17:10:07]
$ diff -rauN /etc/pimd.conf.bak /etc/pimd.conf
--- /etc/pimd.conf.bak	2021-09-27 14:49:18.706881067 +0800
+++ /etc/pimd.conf	2021-10-19 15:40:35.242644448 +0800
@@ -112,7 +112,9 @@

 # By default, all non-loopback multicast capable interfaces are enabled.
 # If you want to use loopback, set the interface multicast flag on it.
-#phyint eth0 disable
+phyint eth3 disable  # 关闭不想要进行组播的端口

 # IGMP default query interval and querier timeout.  The latter should
 # per RFC always be (robustness * interval) + (query-response / 2), for
@@ -132,7 +134,7 @@
 #group-prefix 224.0.0.0 masklen 4

 # Static rendez-vous point
-#rp-address 192.168.10.1 224.0.0.0/4  # 自选举方式
+rp-address 10.10.10.1 224.0.0.0/4  # 自选举太慢，手动指定汇聚点(这里用gre接口ip,也可用routerA的eth0的ip 10.1.1.1)

 # Switch to shortest-path tree after first packet, but only after 100 sec.
 spt-threshold packets 0 interval 100

# root @ routerC in / [17:22:37]
$ systemctl restart pimd.service

查看组播路由

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# root @ routerA in / [17:22:13]
$ pimd -r
Virtual Interface Table ======================================================
Vif  Local Address    Subnet              Thresh  Flags      Neighbors
---  ---------------  ------------------  ------  ---------  -----------------
  0  10.1.1.1         10.1.1/24                1  DR NO-NBR
  1  20.1.1.1         20.1.1/24                1  DR NO-NBR
  2  10.10.10.1       10.10.10.1/32            1  PIM        10.10.10.2
  3  10.1.1.1         register_vif0            1

 Vif  SSM Group        Sources

Multicast Routing Table ======================================================
----------------------------------- (*,G) ------------------------------------
Source           Group            RP Address       Flags
---------------  ---------------  ---------------  ---------------------------
INADDR_ANY       239.255.255.249  10.10.10.1       WC RP
Joined   oifs: ..j.
Pruned   oifs: ....
Leaves   oifs: ....
Asserted oifs: ....
Outgoing oifs: ..o.
Incoming     : ...I

TIMERS:  Entry    JP    RS  Assert VIFS:  0  1  2  3
           200    55     0       0        0  0 200  0
----------------------------------- (S,G) ------------------------------------
Source           Group            RP Address       Flags
---------------  ---------------  ---------------  ---------------------------
10.1.1.2         239.255.255.249  10.10.10.1       SPT CACHE SG
Joined   oifs: ..jj
Pruned   oifs: ....
Leaves   oifs: ....
Asserted oifs: ....
Outgoing oifs: ..oo
Incoming     : I...

TIMERS:  Entry    JP    RS  Assert VIFS:  0  1  2  3
           165    20     0       0        0  0 140  0
Source           Group            RP Address       Flags
---------------  ---------------  ---------------  ---------------------------
10.10.10.1       239.255.255.249  10.10.10.1       RP SG
Joined   oifs: ....
Pruned   oifs: ..p.
Leaves   oifs: ....
Asserted oifs: ....
Outgoing oifs: ....
Incoming     : ...I

TIMERS:  Entry    JP    RS  Assert VIFS:  0  1  2  3
           205    55     0       0        0  0  0  0
--------------------------------- (*,*,G) ------------------------------------
Number of Groups: 1
Number of Cache MIRRORs: 1
------------------------------------------------------------------------------


# root @ routerA in / [17:24:23]
$ ip mroute show  # 看到PC1发的组播239.255.255.249数据从eth0进来，从gre1出去
(10.1.1.2, 239.255.255.249)      Iif: eth0       Oifs: gre1 pimreg
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# root @ routerC in / [17:26:09]
$ pimd -r
Virtual Interface Table ======================================================
Vif  Local Address    Subnet              Thresh  Flags      Neighbors
---  ---------------  ------------------  ------  ---------  -----------------
  0  10.2.1.1         10.2.1/24                1  DR NO-NBR
  1  30.1.1.2         30.1.1/24                1  DR NO-NBR
  2  192.168.255.1    192.168.255              1  DISABLED
  3  10.10.10.2       10.10.10.2/32            1  DR PIM     10.10.10.1
  4  10.2.1.1         register_vif0            1

 Vif  SSM Group        Sources

Multicast Routing Table ======================================================
----------------------------------- (*,G) ------------------------------------
Source           Group            RP Address       Flags
---------------  ---------------  ---------------  ---------------------------
INADDR_ANY       239.255.255.249  10.10.10.1       WC RP
Joined   oifs: .....
Pruned   oifs: .....
Leaves   oifs: l....
Asserted oifs: .....
Outgoing oifs: o....
Incoming     : ...I.

TIMERS:  Entry    JP    RS  Assert VIFS:  0  1  2  3  4
             0    55     0       0        0  0  0  0  0
----------------------------------- (S,G) ------------------------------------
Source           Group            RP Address       Flags
---------------  ---------------  ---------------  ---------------------------
10.10.10.1       239.255.255.249  10.10.10.1       SPT CACHE SG
Joined   oifs: ....j
Pruned   oifs: ....p
Leaves   oifs: l....
Asserted oifs: .....
Outgoing oifs: o....
Incoming     : ...I.

TIMERS:  Entry    JP    RS  Assert VIFS:  0  1  2  3  4
           195    55     1       0        0  0  0  0  0
--------------------------------- (*,*,G) ------------------------------------
Number of Groups: 1
Number of Cache MIRRORs: 1
------------------------------------------------------------------------------


# root @ routerC in / [17:26:10]
$ ip mroute show  # 看到组播239.255.255.249数据从gre1进来，从eth0出去发给PC2
(10.10.10.1, 239.255.255.249)    Iif: gre1       Oifs: eth0 pimreg

接收端PC2

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# zh @ li in ~ [17:35:30]
$ ./rcver 239.255.255.249 enp2s0
---MESSAGE FROM:10.2.1.1:44853---
[i am the 32822th message to 239.255.255.249]

---MESSAGE FROM:10.2.1.1:44853---
[i am the 32821th message to 239.255.255.249]
...