ilearnopenstack: How to configure external connectivity for a cirros VM using openvswitch, in openstack installed on oracle virtual box

Hi Everyone, This post details about the internals of network connectivity of a VM to the external world. The VM is built on cirros image. The openstack is deployed as all in one on a centos VM. The openstack flavor is liberty.

We will see the changes in OVS bridge as we proceed further.

1) Initially there is no VM, and no network created.

[root@os ~(admin)]# nova list;

+----+------+--------+------------+-------------+----------+

+----+------+--------+------------+-------------+----------+

[root@os ~(admin)]# neutron net-list

[root@os ~(admin)]# neutron subnet-list

[root@os ~(admin)]# neutron router-list

[root@os ~(admin)]# brctl show

bridge name bridge id STP enabled interfaces

[root@os ~(admin)]#

Initially when there is no router, no network:

[root@os ~(admin)]# ovs-vsctl show

7a2fa294-0a32-4a8b-ac76-7a4456632c1c

Bridge br-int

fail_mode: secure

Port br-int

Interface br-int

type: internal

Port patch-tun ==============> interconnection with br-tun

Interface patch-tun

type: patch

options: {peer=patch-int}

Bridge br-ex

Port br-ex

Interface br-ex

type: internal

Bridge br-tun

fail_mode: secure

Port patch-int

Interface patch-int

type: patch

options: {peer=patch-tun}

Port br-tun

Interface br-tun

type: internal

ovs_version: "2.4.0"

[root@os ~(admin)]# ip netns list

[root@os ~(admin)]#

2) Lets create an internal network and and attach a subnet to it. The network type would be "VXLAN"

[root@os ~(admin)]# neutron net-create internal_net

Created a new network:

+---------------------------+--------------------------------------------------+

| Field | Value |

+---------------------------+--------------------------------------------------+

| admin_state_up | True |

| id | 3bdec66c-db6c-4367-93fb-d3ce2d8bbe87 |

| mtu | 0 |

| name | internal_net |

| provider:network_type | vxlan |

| provider:physical_network | |

| provider:segmentation_id | 45 |

| router:external | False |

| shared | False |

| status | ACTIVE |

| subnets | |

| tenant_id | e8c1a7908399409fa678e19cb3183b7b |

+---------------------------+--------------------------------------+

[root@os ~(admin)]# neutron subnet-create internal_net 10.10.10.0/24 --name inetrnal_subnet --enable-dhcp --gateway 10.10.10.254

Created a new subnet:

+-------------------+------------------------------------------------+

| Field | Value |

+-------------------+------------------------------------------------+

| allocation_pools | {"start": "10.10.10.1", "end": "10.10.10.253"} |

| cidr | 10.10.10.0/24 |

| dns_nameservers | |

| enable_dhcp | True |

| gateway_ip | 10.10.10.254 |

| host_routes | |

| id | 9e01b1eb-5d21-41f3-b8a2-13e98da4f835 |

| ip_version | 4 |

| ipv6_address_mode | |

| ipv6_ra_mode | |

| name | inetrnal_subnet |

| network_id | 3bdec66c-db6c-4367-93fb-d3ce2d8bbe87 |

| subnetpool_id | |

| tenant_id | e8c1a7908399409fa678e19cb3183b7b |

+-------------------+------------------------------------------------+

[root@os ~(admin)]# ip netns

qdhcp-3bdec66c-db6c-4367-93fb-d3ce2d8bbe87 =======================>> DHCP created

[root@os ~(admin)]# ip netns exec qdhcp-3bdec66c-db6c-4367-93fb-d3ce2d8bbe87 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

13: tap07381c2d-2f: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN

link/ether fa:16:3e:19:9d:62 brd ff:ff:ff:ff:ff:ff

inet 10.10.10.1/24 brd 10.10.10.255 scope global tap07381c2d-2f ====================> DHCP has IP of 10.10.10.1

valid_lft forever preferred_lft forever

inet6 fe80::f816:3eff:fe19:9d62/64 scope link

valid_lft forever preferred_lft forever

[root@os ~(admin)]# ovs-vsctl show

7a2fa294-0a32-4a8b-ac76-7a4456632c1c

Bridge br-int

fail_mode: secure

Port br-int

Interface br-int

type: internal

Port "tap07381c2d-2f" =========================>> tab port created by dhcp for VM

tag: 1

Interface "tap07381c2d-2f"

type: internal

Port patch-tun

Interface patch-tun

type: patch

options: {peer=patch-int}

Bridge br-ex

Port br-ex

Interface br-ex

type: internal

Bridge br-tun

fail_mode: secure

Port patch-int

Interface patch-int

type: patch

options: {peer=patch-tun}

Port br-tun

Interface br-tun

type: internal

ovs_version: "2.4.0"

[root@os ~(admin)]#

3) Spin a cirros virtual machine.

[root@os ~(admin)]# nova boot cirros --flavor=m1.tiny --image=cirros --nic net-id=3bdec66c-db6c-4367-93fb-d3ce2d8bbe87

+--------------------------------------+------------------------------------------------+

| Property | Value |

+--------------------------------------+------------------------------------------------+

| OS-DCF:diskConfig | MANUAL |

| OS-EXT-AZ:availability_zone | |

| OS-EXT-SRV-ATTR:host | - |

| OS-EXT-SRV-ATTR:hypervisor_hostname | - |

| OS-EXT-SRV-ATTR:instance_name | instance-00000002 |

| OS-EXT-STS:power_state | 0 |

| OS-EXT-STS:task_state | scheduling |

| OS-EXT-STS:vm_state | building |

| OS-SRV-USG:launched_at | - |

| OS-SRV-USG:terminated_at | - |

| accessIPv4 | |

| accessIPv6 | |

| adminPass | Tim3qy2GeWYv |

| config_drive | |

| created | 2018-01-29T14:30:40Z |

| flavor | m1.tiny (5b9347ee-7a3b-4270-ac31-afdfd9c17eb0) |

| hostId | |

| id | 51e724d6-88ff-4033-bd83-0c288da65eb7 |

| image | cirros (1778216e-714d-4571-95a6-6ad83723d5de) |

| key_name | - |

| metadata | {} |

| name | cirros |

| os-extended-volumes:volumes_attached | [] |

| progress | 0 |

| security_groups | default |

| status | BUILD |

| tenant_id | e8c1a7908399409fa678e19cb3183b7b |

| updated | 2018-01-29T14:30:40Z |

| user_id | 808cb4bfeb944a088fe5b3977ac088d0 |

+--------------------------------------+------------------------------------------------+

[root@os ~(admin)]# brctl show

bridge name bridge id STP enabled interfaces

qbra06bbf9c-ca 8000.7a3bbc5fbc73 no qvba06bbf9c-ca

tapa06bbf9c-ca

[root@os ~(admin)]# ovs-vsctl show

7a2fa294-0a32-4a8b-ac76-7a4456632c1c

Bridge br-int

fail_mode: secure

Port br-int

Interface br-int

type: internal

Port "qvoa06bbf9c-ca" ===============> now br-int has connection with linux bridge

tag: 1

Interface "qvoa06bbf9c-ca"

Port "tap07381c2d-2f"

tag: 1

Interface "tap07381c2d-2f"

type: internal

Port patch-tun

Interface patch-tun

type: patch

options: {peer=patch-int}

Bridge br-ex

Port br-ex

Interface br-ex

type: internal

Bridge br-tun

fail_mode: secure

Port patch-int

Interface patch-int

type: patch

options: {peer=patch-tun}

Port br-tun

Interface br-tun

type: internal

ovs_version: "2.4.0"

[root@os ~(admin)]#

4) Lets create a router so the traffic can be routed to outer world.

[root@os ~(admin)]# neutron router-create router

+-----------------------+--------------------------------------+

| Field | Value |

+-----------------------+--------------------------------------+

| admin_state_up | True |

| distributed | False |

| external_gateway_info | |

| ha | False |

| id | 98a84588-9ce7-451a-9693-55eede6451f1 |

| name | router |

| routes | |

| status | ACTIVE |

| tenant_id | e8c1a7908399409fa678e19cb3183b7b |

+-----------------------+--------------------------------------+

[root@os ~(admin)]# ip netns

qdhcp-3bdec66c-db6c-4367-93fb-d3ce2d8bbe87

5) Now add Interface (subnet of the internal network)

[root@os ~(admin)]#neutron router-interface-add router subnet=9e01b1eb-5d21-41f3-b8a2-13e98da4f835

[root@os ~(admin)]# ip netns

qrouter-98a84588-9ce7-451a-9693-55eede6451f1

qdhcp-3bdec66c-db6c-4367-93fb-d3ce2d8bbe87

[root@os ~(admin)]# ip netns exec qrouter-98a84588-9ce7-451a-9693-55eede6451f1 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

18: qr-9a6e1d84-3c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN

link/ether fa:16:3e:12:37:66 brd ff:ff:ff:ff:ff:ff

inet 10.10.10.254/24 brd 10.10.10.255 scope global qr-9a6e1d84-3c==================================> this router port has the gateway IP of subnet created above

valid_lft forever preferred_lft forever

inet6 fe80::f816:3eff:fe12:3766/64 scope link

valid_lft forever preferred_lft forever

[root@os ~(admin)]#

[root@os ~(admin)]# ovs-vsctl show

7a2fa294-0a32-4a8b-ac76-7a4456632c1c

Bridge br-int

fail_mode: secure

Port br-int

Interface br-int

type: internal

Port "qvoa06bbf9c-ca"

tag: 1

Interface "qvoa06bbf9c-ca"

Port "tap07381c2d-2f"

tag: 1

Interface "tap07381c2d-2f"

type: internal

Port "qr-9a6e1d84-3c"

tag: 1

Interface "qr-9a6e1d84-3c" ===============================>> created after router creation

type: internal

Port patch-tun

Interface patch-tun

type: patch

options: {peer=patch-int}

Bridge br-ex

Port br-ex

Interface br-ex

type: internal

Bridge br-tun

fail_mode: secure

Port patch-int

Interface patch-int

type: patch

options: {peer=patch-tun}

Port br-tun

Interface br-tun

type: internal

ovs_version: "2.4.0"

[root@os ~(admin)]# brctl show

bridge name bridge id STP enabled interfaces

qbra06bbf9c-ca 8000.7a3bbc5fbc73 no qvba06bbf9c-ca

tapa06bbf9c-ca

[root@os ~(admin)]#

6) Since we are using ovs, lets configure external bridge, i.e br-ex. For external connectivity. The host virtual machine, where openstack is installed will act as external server for this use case. For this I will dettach the native network interface and attach it to br-ex. Will also flush the IP address of this interface and assign it to br-ex

ifconfig enp0s3 0

dhclient br-ex =====> make sure that br-ex gets the same ip that enp0s3 had, if not assign it manually.
ifconfig br-ex 192.168.56.102/24 up

7) Create a public network

[root@os ~(admin)]# neutron net-create public --provider:network_type vxlan --router:external=true

Created a new network:

+---------------------------+--------------------------------------+

| Field | Value |

+---------------------------+--------------------------------------+

| admin_state_up | True |

| id | 4c7d9cec-6013-488b-8d5d-0ed13c228876 |

| mtu | 0 |

| name | public |

| provider:network_type | vxlan |

| provider:physical_network | |

| provider:segmentation_id | 44 |

| router:external | True |

| shared | False |

| status | ACTIVE |

| subnets | |

| tenant_id | e8c1a7908399409fa678e19cb3183b7b |

+---------------------------+--------------------------------------+

[root@os ~(admin)]#

[root@os ~(admin)]# neutron subnet-create public 192.168.56.0/24 --name pub-subnet --gateway 192.168.56.1 --disable-dhcp --allocation-pool start=192.168.56.200,end=192.168.56.210 =================================>> allocation pool is mandatory here as floating ip will be assigned from this pool

Created a new subnet:

+-------------------+------------------------------------------------------+

| Field | Value |

+-------------------+------------------------------------------------------+

| allocation_pools | {"start": "192.168.56.200", "end": "192.168.56.210"} |

| cidr | 192.168.56.0/24 |

| dns_nameservers | |

| enable_dhcp | False |

| gateway_ip | 192.168.56.1 |

| host_routes | |

| id | 23db7b6d-8196-42e5-8283-9f38cfe9a1cb |

| ip_version | 4 |

| ipv6_address_mode | |

| ipv6_ra_mode | |

| name | pub-subnet |

| network_id | 4c7d9cec-6013-488b-8d5d-0ed13c228876 |

| subnetpool_id | |

| tenant_id | e8c1a7908399409fa678e19cb3183b7b |

+-------------------+------------------------------------------------------+

[root@os ~(admin)]#

8) Set the gateway so the router will use the allocated pool of IPs of external network.

When one network wants to talk to another, add them as interfaces but when both networks wants to connect with external world then set the gateway of the external network in router.

[root@os ~(admin)]# ip netns
qrouter-98a84588-9ce7-451a-9693-55eede6451f1
qdhcp-3bdec66c-db6c-4367-93fb-d3ce2d8bbe87
[root@os ~(admin)]# ip netns qrouter-98a84588-9ce7-451a-9693-55eede6451f1 bash
Command "qrouter-98a84588-9ce7-451a-9693-55eede6451f1" is unknown, try "ip netns help".
[root@os ~(admin)]# ip netns exec qrouter-98a84588-9ce7-451a-9693-55eede6451f1 bash
[root@os ~(admin)]# ifconfig
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

qg-75980405-14: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.56.200 netmask 255.255.255.0 broadcast 192.168.56.255
inet6 fe80::f816:3eff:fe3c:22d4 prefixlen 64 scopeid 0x20<link>
ether fa:16:3e:3c:22:d4 txqueuelen 0 (Ethernet)
RX packets 15 bytes 1715 (1.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 13 bytes 1074 (1.0 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

qr-9a6e1d84-3c: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.10.10.254 netmask 255.255.255.0 broadcast 10.10.10.255
inet6 fe80::f816:3eff:fe12:3766 prefixlen 64 scopeid 0x20<link>
ether fa:16:3e:12:37:66 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10 bytes 864 (864.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

Now from the router the external server is reachable.
[root@os ~(admin)]# ping 192.168.56.102
PING 192.168.56.102 (192.168.56.102) 56(84) bytes of data.
64 bytes from 192.168.56.102: icmp_seq=1 ttl=64 time=4.19 ms
64 bytes from 192.168.56.102: icmp_seq=2 ttl=64 time=0.247 ms

And form dhcp, cirros VM is reachable

[root@os ~(admin)]# ip netns
qrouter-98a84588-9ce7-451a-9693-55eede6451f1
qdhcp-3bdec66c-db6c-4367-93fb-d3ce2d8bbe87
[root@os ~(admin)]# ip netns exec qdhcp-3bdec66c-db6c-4367-93fb-d3ce2d8bbe87 bash
[root@os ~(admin)]# ifconfig
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 13 bytes 1408 (1.3 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 13 bytes 1408 (1.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

tap07381c2d-2f: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.10.10.1 netmask 255.255.255.0 broadcast 10.10.10.255
inet6 fe80::f816:3eff:fe19:9d62 prefixlen 64 scopeid 0x20<link>
ether fa:16:3e:19:9d:62 txqueuelen 0 (Ethernet)
RX packets 13 bytes 1522 (1.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 32 bytes 2497 (2.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

[root@os ~(admin)]# ping 10.10.10.2
PING 10.10.10.2 (10.10.10.2) 56(84) bytes of data.
64 bytes from 10.10.10.2: icmp_seq=1 ttl=64 time=8.38 ms
64 bytes from 10.10.10.2: icmp_seq=2 ttl=64 time=3.51 ms

[root@os ~(admin)]# ssh cirros@10.10.10.2
cirros@10.10.10.2's password:
$ ifconfig
eth0 Link encap:Ethernet HWaddr FA:16:3E:6B:C8:83
inet addr:10.10.10.2 Bcast:10.10.10.255 Mask:255.255.255.0
inet6 addr: fe80::f816:3eff:fe6b:c883/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1400 Metric:1
RX packets:117 errors:0 dropped:0 overruns:0 frame:0
TX packets:138 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:14765 (14.4 KiB) TX bytes:14418 (14.0 KiB)

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: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)

From VMs the external server is reachable and sshable now.

$ ping 192.168.56.102
PING 192.168.56.102 (192.168.56.102): 56 data bytes
64 bytes from 192.168.56.102: seq=0 ttl=63 time=24.940 ms
64 bytes from 192.168.56.102: seq=1 ttl=63 time=7.214 ms
^C
--- 192.168.56.102 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 7.214/16.077/24.940 ms
$ ssh root@192.168.56.102
root@192.168.56.102's password:
Last login: Tue Jan 30 03:02:34 2018 from 192.168.56.1
[root@os ~]# ls
anaconda-ks.cfg ans.cfg keystonerc_admin liberty sec-key.pem
[root@os ~]# hostname -I
192.168.56.102
[root@os ~]#

[root@os ~(admin)]# neutron router-show router
+-----------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-----------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| admin_state_up | True |
| distributed | False |
| external_gateway_info | {"network_id": "4c7d9cec-6013-488b-8d5d-0ed13c228876", "enable_snat": true, "external_fixed_ips": [{"subnet_id": "23db7b6d-8196-42e5-8283-9f38cfe9a1cb", "ip_address": "192.168.56.200"}]} |
| ha | False |
| id | 98a84588-9ce7-451a-9693-55eede6451f1 |
| name | router |
| routes | |
| status | ACTIVE |
| tenant_id | e8c1a7908399409fa678e19cb3183b7b |
+-----------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
[root@os ~(admin)]#

9) Till now we have made external server reachable from tenant VM, but vice-versa is not true. To make the VM reachable from external server, we need to create and assign the floating ip.

[root@os ~(admin)]# neutron floatingip-create public

[root@os ~(admin)]# nova floating-ip-list
+--------------------------------------+----------------+-----------+----------+--------+
| Id | IP | Server Id | Fixed IP | Pool |
+--------------------------------------+----------------+-----------+----------+--------+
| 68f29d37-c3ec-406e-b69a-c342efc7dcff | 192.168.56.201 | - | - | public |
+--------------------------------------+----------------+-----------+----------+--------+
[root@os ~(admin)]# nova floating-ip-associate cirros 192.168.56.201
[root@os ~(admin)]# nova list
+--------------------------------------+--------+--------+------------+-------------+-----------------------------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+--------+--------+------------+-------------+-----------------------------------------+
| 51e724d6-88ff-4033-bd83-0c288da65eb7 | cirros | ACTIVE | - | Running | internal_net=10.10.10.2, 192.168.56.201 |
+--------------------------------------+--------+--------+------------+-------------+-----------------------------------------+
[root@os ~(admin)]# ping 192.168.56.201
PING 192.168.56.201 (192.168.56.201) 56(84) bytes of data.
64 bytes from 192.168.56.201: icmp_seq=1 ttl=63 time=119 ms
64 bytes from 192.168.56.201: icmp_seq=2 ttl=63 time=4.15 ms

[root@os ~(admin)]# ssh cirros@192.168.56.201
The authenticity of host '192.168.56.201 (192.168.56.201)' can't be established.
RSA key fingerprint is 8e:b7:98:45:9c:57:ca:02:ae:82:21:a0:f8:9c:7b:1e.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.56.201' (RSA) to the list of known hosts.
cirros@192.168.56.201's password:
$ ls
$ hostname
cirros
$ exit

[root@os ~(admin)]# ip netns exec qrouter-98a84588-9ce7-451a-9693-55eede6451f1 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
13: qr-9a6e1d84-3c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
link/ether fa:16:3e:12:37:66 brd ff:ff:ff:ff:ff:ff
inet 10.10.10.254/24 brd 10.10.10.255 scope global qr-9a6e1d84-3c
valid_lft forever preferred_lft forever
inet6 fe80::f816:3eff:fe12:3766/64 scope link
valid_lft forever preferred_lft forever
14: qg-75980405-14: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
link/ether fa:16:3e:3c:22:d4 brd ff:ff:ff:ff:ff:ff
inet 192.168.56.200/24 brd 192.168.56.255 scope global qg-75980405-14
valid_lft forever preferred_lft forever
inet 192.168.56.201/32 brd 192.168.56.201 scope global qg-75980405-14
valid_lft forever preferred_lft forever
inet6 fe80::f816:3eff:fe3c:22d4/64 scope link
valid_lft forever preferred_lft forever
[root@os ~(admin)]#

$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1400 qdisc pfifo_fast qlen 1000
link/ether fa:16:3e:6b:c8:83 brd ff:ff:ff:ff:ff:ff
inet 10.10.10.2/24 brd 10.10.10.255 scope global eth0
inet6 fe80::f816:3eff:fe6b:c883/64 scope link
valid_lft forever preferred_lft forever
$

ilearnopenstack

Tuesday 30 January 2018

How to configure external connectivity for a cirros VM using openvswitch, in openstack installed on oracle virtual box

Hi Everyone, This post details about the internals of network connectivity of a VM to the external world. The VM is built on cirros image. The openstack is deployed as all in one on a centos VM. The openstack flavor is liberty.

1) Initially there is no VM, and no network created.

2) Lets create an internal network and and attach a subnet to it. The network type would be "VXLAN"

3) Spin a cirros virtual machine.

4) Lets create a router so the traffic can be routed to outer world.

5) Now add Interface (subnet of the internal network)

7) Create a public network

8) Set the gateway so the router will use the allocated pool of IPs of external network.

9) Till now we have made external server reachable from tenant VM, but vice-versa is not true. To make the VM reachable from external server, we need to create and assign the floating ip.

No comments:

Post a Comment