Neutron 路由器未回复 arp 请求

Question

Neutron Router 可以 ping 通实例，但实例无法 ping 通路由器或外部网络。该实例通过 nova 外部的 DHCP 位于提供商网络上。

以下是从路由器到实例的 ping

[root@rishi2 ~(keystone_admin)]# ip netns exec qrouter-c038097c-62bf-4eba-851c-f0ac060801bb ping 192.168.70.8
PING 192.168.70.8 (192.168.70.8) 56(84) bytes of data.
64 bytes from 192.168.70.8: icmp_seq=1 ttl=64 time=2.47 ms
64 bytes from 192.168.70.8: icmp_seq=2 ttl=64 time=0.340 ms

以下是arp和ip路由表

[root@rishi2 ~(keystone_admin)]# ip netns exec qrouter-c038097c-62bf-4eba-851c-f0ac060801bb ip r
default via 172.16.2.1 dev qg-b1e2ea82-67
10.10.10.0/24 dev qr-ee12b390-25  proto kernel  scope link  src 10.10.10.1
10.10.20.0/24 dev qr-88d204dd-45  proto kernel  scope link  src 10.10.20.1
172.16.2.0/24 dev qg-b1e2ea82-67  proto kernel  scope link  src 172.16.2.224
192.168.70.0/24 dev qg-b1e2ea82-67  scope link
192.168.70.0/24 dev qr-7f4d988f-bf  proto kernel  scope link  src 192.168.70.1
192.168.80.0/24 dev qg-b1e2ea82-67  scope link
192.168.80.0/24 dev qr-f44f0b41-53  proto kernel  scope link  src 192.168.80.1



[root@rishi2 ~(keystone_admin)]# ip netns exec qrouter-c038097c-62bf-4eba-851c-f0ac060801bb ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
7: qr-88d204dd-45: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether fa:16:3e:5f:fa:e0 brd ff:ff:ff:ff:ff:ff
    inet 10.10.20.1/24 brd 10.10.20.255 scope global qr-88d204dd-45
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fe5f:fae0/64 scope link
       valid_lft forever preferred_lft forever
8: qr-ee12b390-25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether fa:16:3e:c4:24:99 brd ff:ff:ff:ff:ff:ff
    inet 10.10.10.1/24 brd 10.10.10.255 scope global qr-ee12b390-25
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fec4:2499/64 scope link
       valid_lft forever preferred_lft forever
9: qg-b1e2ea82-67: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether fa:16:3e:6a:82:3b brd ff:ff:ff:ff:ff:ff
    inet 172.16.2.224/24 brd 172.16.2.255 scope global qg-b1e2ea82-67
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fe6a:823b/64 scope link
       valid_lft forever preferred_lft forever
13: qr-f44f0b41-53: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether fa:16:3e:22:1d:b1 brd ff:ff:ff:ff:ff:ff
    inet 192.168.80.1/24 brd 192.168.80.255 scope global qr-f44f0b41-53
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fe22:1db1/64 scope link
       valid_lft forever preferred_lft forever
14: qr-7f4d988f-bf: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether fa:16:3e:73:f5:93 brd ff:ff:ff:ff:ff:ff
    inet 192.168.70.1/24 brd 192.168.70.255 scope global qr-7f4d988f-bf
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fe73:f593/64 scope link
       valid_lft forever preferred_lft forever
[root@rishi2 ~(keystone_admin)]#

有什么想法为什么中子路由器不响应 arp 吗？

[root@rishi2 ~(keystone_admin)]# ip netns exec qrouter-c038097c-62bf-4eba-851c-f0ac060801bb tcpdump -n -i qr-f44f0b41-53
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on qr-f44f0b41-53, link-type EN10MB (Ethernet), capture size 65535 bytes
02:24:28.322541 ARP, Request who-has 192.168.70.1 tell 192.168.70.8, length 42
02:24:29.317836 ARP, Request who-has 192.168.70.1 tell 192.168.70.8, length 42
02:24:29.679404 IP 172.16.2.66 > 224.0.0.22: igmp v3 report, 1 group record(s)
02:24:30.317832 ARP, Request who-has 192.168.70.1 tell 192.168.70.8, length 42
02:24:31.715735 IP 172.16.2.151.54985 > 224.0.0.252.hostmon: UDP, length 24
02:24:31.715722 IP 172.16.2.151.netbios-ns > 172.16.2.255.netbios-ns: NBT UDP PACKET(137): QUERY; REQUEST; BROADCAST
02:24:32.135843 IP 172.16.2.151.54985 > 224.0.0.252.hostmon: UDP, length 24
02:24:32.320279 ARP, Request who-has 192.168.70.1 tell 192.168.70.8, length 42
02:24:32.479140 IP 172.16.2.151.netbios-ns > 172.16.2.255.netbios-ns: NBT UDP PACKET(137): QUERY; REQUEST; BROADCAST
02:24:33.276089 IP 172.16.2.151.netbios-ns > 172.16.2.255.netbios-ns: NBT UDP PACKET(137): QUERY; REQUEST; BROADCAST
02:24:33.319842 ARP, Request who-has 192.168.70.1 tell 192.168.70.8, length 42

Answer 1

Neutron 路由器无法在同一网络的子网之间路由。当子网分离并保留在不同的网络上时 - 路由器工作正常。

由此可能还不清楚根本原因。

Answer 2

就我而言，我禁用了 DHCP 代理。我真的不知道我的实例如何收到 IP 地址。

我认为路由器使用 DHCP 代理来响应 ARP 请求。也许我配置错误？

我对 Openstack 还很陌生。

重新启用 DHCP 代理解决了我的问题，路由器现在能够响应外部 ARP 请求。