红帽全球峰会6.7. 在命名空间内执行高级 ICMP 测试 (ML2/OVS)
您可以使用 tcpdump 和 ping 命令的组合对 Red Hat Openstack Platform (RHOSP) ML2/OVS 网络进行故障排除。
先决条件
- RHOSP 部署，使用 ML2/OVS 作为网络服务(neutron)默认机制驱动程序。
流程
使用
tcpdump命令捕获 ICMP 流量：示例
ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b tcpdump -qnntpi any icmp
# ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b tcpdump -qnntpi any icmpCopy to Clipboard Copied! Toggle word wrap Toggle overflow 在一个单独的命令行窗口中，对外部网络执行 ping 测试：
示例
ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b ping www.example.com
# ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b ping www.example.comCopy to Clipboard Copied! Toggle word wrap Toggle overflow 在运行 tcpdump 会话的终端中，观察 ping 测试的详细结果。
输出示例
tcpdump: listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes IP (tos 0xc0, ttl 64, id 55447, offset 0, flags [none], proto ICMP (1), length 88) 172.24.4.228 > 172.24.4.228: ICMP host 192.168.200.20 unreachable, length 68 IP (tos 0x0, ttl 64, id 22976, offset 0, flags [DF], proto UDP (17), length 60) 172.24.4.228.40278 > 192.168.200.21: [bad udp cksum 0xfa7b -> 0xe235!] UDP, length 32tcpdump: listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes IP (tos 0xc0, ttl 64, id 55447, offset 0, flags [none], proto ICMP (1), length 88) 172.24.4.228 > 172.24.4.228: ICMP host 192.168.200.20 unreachable, length 68 IP (tos 0x0, ttl 64, id 22976, offset 0, flags [DF], proto UDP (17), length 60) 172.24.4.228.40278 > 192.168.200.21: [bad udp cksum 0xfa7b -> 0xe235!] UDP, length 32Copy to Clipboard Copied! Toggle word wrap Toggle overflow
注意
当您对流量执行 tcpdump 分析时，您会看到对路由器接口的响应数据包标题，而不是虚拟机实例。这是预期的行为，因为 qrouter 在返回数据包上执行目标网络地址转换 (DNAT)。
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