[Openstack-operators] Problems understanding/running the flat network mode

Christian Wittwer wittwerch at gmail.com
Sat Aug 13 10:16:19 UTC 2011


Hi,
I'm currently building a small proof of concept using OpenStack 2011.2
on Ubuntu 10.04.3 LTS. The setup looks like this.

os-controller
Physical server with one interface, runs nova-network and nova-scheduler.

root at os-controller:/etc/network# ifconfig
br100     Link encap:Ethernet  HWaddr 00:22:19:6d:87:3a
          inet addr:10.2.3.7  Bcast:10.2.3.255  Mask:255.255.254.0
          inet6 addr: fe80::222:19ff:fe6d:873a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:104693 errors:0 dropped:0 overruns:0 frame:0
          TX packets:48841 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:8637793 (8.6 MB)  TX bytes:5173040 (5.1 MB)

eth0      Link encap:Ethernet  HWaddr 00:22:19:6d:87:3a
          inet6 addr: fe80::222:19ff:fe6d:873a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:513207 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1241603 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:47340200 (47.3 MB)  TX bytes:1578854262 (1.5 GB)
          Interrupt:16 Memory:f8000000-f8012800

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:902486 errors:0 dropped:0 overruns:0 frame:0
          TX packets:902486 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:76554927 (76.5 MB)  TX bytes:76554927 (76.5 MB)

virbr0    Link encap:Ethernet  HWaddr 26:29:f0:4b:12:4a
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

root at os-controller:/etc/network# brctl show
bridge name     bridge id               STP enabled     interfaces
br100           8000.0022196d873a       no              eth0
virbr0          8000.000000000000       yes

os-compute1
Physical server with one interface, runs nova-compute.

root at os-compute1:/etc/nova# ifconfig
br100     Link encap:Ethernet  HWaddr 00:22:19:54:01:ef
          inet addr:10.2.3.101  Bcast:10.2.3.255  Mask:255.255.254.0
          inet6 addr: fe80::222:19ff:fe54:1ef/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1270917 errors:0 dropped:0 overruns:0 frame:0
          TX packets:494417 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1559046135 (1.5 GB)  TX bytes:44115042 (44.1 MB)

eth0      Link encap:Ethernet  HWaddr 00:22:19:54:01:ef
          inet6 addr: fe80::222:19ff:fe54:1ef/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1269412 errors:0 dropped:0 overruns:0 frame:0
          TX packets:496714 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1581861586 (1.5 GB)  TX bytes:46244418 (46.2 MB)
          Interrupt:16 Memory:da000000-da012800

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:21 errors:0 dropped:0 overruns:0 frame:0
          TX packets:21 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2024 (2.0 KB)  TX bytes:2024 (2.0 KB)

virbr0    Link encap:Ethernet  HWaddr b2:ea:48:a0:07:1b
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B)  TX bytes:252 (252.0 B)

vnet0     Link encap:Ethernet  HWaddr fe:16:3e:3c:ba:2a
          inet6 addr: fe80::fc16:3eff:fe3c:ba2a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:581 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3522 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500
          RX bytes:24618 (24.6 KB)  TX bytes:474829 (474.8 KB)

vnet1     Link encap:Ethernet  HWaddr fe:16:3e:06:43:11
          inet6 addr: fe80::fc16:3eff:fe06:4311/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:240 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1471 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500
          RX bytes:10296 (10.2 KB)  TX bytes:210510 (210.5 KB)

root at os-compute1:/etc/nova# brctl show
bridge name     bridge id               STP enabled     interfaces
br100           8000.0022195401ef       no              eth0
                                                        vnet0
                                                        vnet1
virbr0          8000.000000000000       yes

The nova.conf looks like this.

--dhcpbridge_flagfile=/etc/nova/nova.conf
--dhcpbridge=/usr/bin/nova-dhcpbridge
--logdir=/var/log/nova
--state_path=/var/lib/nova
--lock_path=/var/lock/nova
--verbose
--s3_host=10.2.3.7
--rabbit_host=10.2.3.7
--cc_host=10.2.3.7
--ec2_url=http://10.2.3.7:8773/services/Cloud
--fixed_range=192.168.27.0/24
--network_size=253
--FAKE_subdomain=ec2
--routing_source_ip=10.2.3.7
--verbose
--sql_connection=mysql://root:secret@10.2.3.7/nova
--network_manager=nova.network.manager.FlatManager

The private network I've chosen is 192.168.27.0/24.

root at os-controller:/etc/network# nova-manage network list
network                 netmask         start address   DNS
192.168.27.0/29         255.255.255.248 192.168.27.2    8.8.4.4

I can startup a instance, it gets a ip from that pool, but I'm unable
to ping it.

root at os-controller:/etc/network# euca-describe-instances
RESERVATION     r-of7is1i0      BUIS    default
INSTANCE        i-0000000c      ami-20f7c97c    192.168.27.2
192.168.27.2    running None (foo, os-compute1)       0
m1.tiny 2011-08-13T09:34:59Z nova
RESERVATION     r-t9tq3f2q      BUIS    default
INSTANCE        i-0000000d      ami-20f7c97c    192.168.27.3
192.168.27.3    running None (foo, os-compute1)       0
m1.tiny 2011-08-13T09:53:29Z nova

I think there needs to be more configuration done? I had a look at the
database, the gateway for that network is 192.168.27.1.
But where do I have to configure that ip? On the os-controller? Or an
additional route, because I don't have one on both of my nodes.

root at os-compute1:/etc/nova# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0
10.2.2.0        0.0.0.0         255.255.254.0   U     0      0        0 br100
0.0.0.0         10.2.2.1        0.0.0.0         UG    100    0        0 br100

Can somebody help me?

Chris



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