FRR学习第二天

今天学习使用 frr 搭建一个 bgp 网络环境，练习如下功能：

1. 两个 frr 路由器建立邻居关系
2. 将 igp 路由注入 bgp
3. bgp 路由注入 igp
4. 实现两个网络通过动态路由互通

实验拓扑

配置主机

主机 1

#bgp 配置
router bgp 7675
 bgp router-id 192.168.59.128
 neighbor 192.168.59.129 remote-as 7676
 !
!
#配置一个 host
sudo ip netns add ns1 
sudo ip link add veth1 type veth peer name eth0 netns ns1
sudo ip netns exec ns1 ip link set eth0 up
sudo ip netns exec ns1 ip link set lo up
sudo ip netns exec ns1 ip addr add 2.2.2.2/24 dev eth0
sudo ip netns exec ns1 ip route add default via 2.2.2.254 dev eth0
sudo ip link set veth1 up
sudo ip link add br1 type bridge
sudo ip link set br1 up
sudo ip link set veth1 master br1
sudo ip addr add 2.2.2.254/24 dev br1
#打开转发开关
ubuntu@ubuntu:~$ sudo -i
root@ubuntu:~# echo 1 > /proc/sys/net/ipv4/ip_forward

主机 2

#bgp 配置
router bgp 7676
 bgp router-id 192.168.59.129
 neighbor 192.168.59.128 remote-as 7675
 !
!
#配置一个 host
sudo ip netns add ns1 
sudo ip link add veth1 type veth peer name eth0 netns ns1
sudo ip netns exec ns1 ip link set eth0 up
sudo ip netns exec ns1 ip link set lo up
sudo ip netns exec ns1 ip addr add 3.3.3.3/24 dev eth0
sudo ip netns exec ns1 ip route add default via 3.3.3.254 dev eth0
sudo ip link set veth1 up
sudo ip link add br1 type bridge
sudo ip link set br1 up
sudo ip link set veth1 master br1
sudo ip addr add 3.3.3.254/24 dev br1
#打开转发开关
ubuntu@ubuntu:~$ sudo -i
root@ubuntu:~# echo 1 > /proc/sys/net/ipv4/ip_forward

将 IGP 路由注入到 BGP

主机 1

ubuntu(config-router)# network 2.2.2.0/24 

主机 2

ubuntu(config-router)# network 3.3.3.0/24

查看配置结果

主机 1

ubuntu# show ip route 
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
       F - PBR, f - OpenFabric,
       > - selected route, * - FIB route, q - queued route, r - rejected route

K>* 0.0.0.0/0 [0/100] via 192.168.217.2, ens33, 18:24:23
C>* 2.2.2.0/24 is directly connected, br1, 00:35:11
B>* 3.3.3.0/24 [20/0] via 192.168.59.129, ens34, 00:00:15
K>* 169.254.0.0/16 [0/1000] is directly connected, ens34, 18:24:23
C>* 192.168.59.0/24 is directly connected, ens34, 18:24:23
C>* 192.168.217.0/24 is directly connected, ens33, 18:24:23

主机 2

ubuntu# show ip route 
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
       F - PBR, f - OpenFabric,
       > - selected route, * - FIB route, q - queued route, r - rejected route

K>* 0.0.0.0/0 [0/100] via 192.168.217.2, ens33, 13:16:46
B>* 2.2.2.0/24 [20/0] via 192.168.59.128, ens34, 00:45:36
C>* 3.3.3.0/24 is directly connected, br1, 01:07:35
K>* 169.254.0.0/16 [0/1000] is directly connected, ens33, 18:22:49
C>* 192.168.59.0/24 is directly connected, ens34, 18:22:49
C>* 192.168.217.0/24 is directly connected, ens33, 18:22:49
ubuntu# 

从上面可以看出，两个主机分别有了对等体发布的路由，对等体发布的路由会自动注入 igp 路由中。标号为 B >。

测试

主机 1

ubuntu@ubuntu:~$ sudo ip netns exec ns1 ping 3.3.3.3 -c 2
PING 3.3.3.3 (3.3.3.3) 56(84) bytes of data.
64 bytes from 3.3.3.3: icmp_seq=1 ttl=62 time=0.372 ms
64 bytes from 3.3.3.3: icmp_seq=2 ttl=62 time=0.339 ms

--- 3.3.3.3 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 32ms
rtt min/avg/max/mdev = 0.339/0.355/0.372/0.025 ms
ubuntu@ubuntu:~$ 

主机 2

ubuntu@ubuntu:~$ sudo ip netns exec ns1 ping 2.2.2.2 -c 2
PING 2.2.2.2 (2.2.2.2) 56(84) bytes of data.
64 bytes from 2.2.2.2: icmp_seq=1 ttl=62 time=0.564 ms
64 bytes from 2.2.2.2: icmp_seq=2 ttl=62 time=0.359 ms

--- 2.2.2.2 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 3ms
rtt min/avg/max/mdev = 0.359/0.461/0.564/0.104 ms
ubuntu@ubuntu:~$