Demo on VLAB
The goal of this demo is to show how to use VPCs, attach and peer them and run test connectivity between the servers. Examples are based on the default VLAB topology.
You can find instructions on how to setup VLAB in the Overview and Running VLAB sections.
Default topology
The default topology is Spine-Leaf with 2 spines, 2 MCLAG leaves and 1 non-MCLAG leaf. Optionally, you can choose to run
the default Collapsed Core topology using flag --fabric-mode collapsed-core (or -m collapsed-core) which only
consists of 2 switches.
For more details on customizing topologies see the Running VLAB section.
In the default topology, the following Control Node and Switch VMs are created:
graph TD
CN[Control Node]
S1[Spine 1]
S2[Spine 2]
L1[MCLAG Leaf 1]
L2[MCLAG Leaf 2]
L3[Leaf 3]
CN --> L1
CN --> L2
S1 --> L1
S1 --> L2
S2 --> L2
S2 --> L3As well as the following test servers:
graph TD
L1[MCLAG Leaf 1]
L2[MCLAG Leaf 2]
L3[Leaf 3]
L4[Leaf 4]
TS1[Test Server 1]
TS2[Test Server 2]
TS3[Test Server 3]
TS4[Test Server 4]
TS5[Test Server 5]
TS6[Test Server 6]
TS1 --> L1
TS1 --> L2
TS2 --> L1
TS2 --> L2
TS3 --> L1
TS4 --> L2
TS5 --> L3
TS6 --> L4Creating and attaching VPCs
You can create and attach VPCs to the VMs using the kubectl fabric vpc command on the Control Node or outside of the
cluster using the kubeconfig. For example, run the following commands to create 2 VPCs with a single subnet each, a DHCP
server enabled with its optional IP address range start defined, and to attach them to some of the test servers:
core@control-1 ~ $ kubectl get conn | grep server
server-01--mclag--leaf-01--leaf-02 mclag 5h13m
server-02--mclag--leaf-01--leaf-02 mclag 5h13m
server-03--unbundled--leaf-01 unbundled 5h13m
server-04--bundled--leaf-02 bundled 5h13m
server-05--unbundled--leaf-03 unbundled 5h13m
server-06--bundled--leaf-03 bundled 5h13m
core@control-1 ~ $ kubectl fabric vpc create --name vpc-1 --subnet 10.0.1.0/24 --vlan 1001 --dhcp --dhcp-start 10.0.1.10
06:48:46 INF VPC created name=vpc-1
core@control-1 ~ $ kubectl fabric vpc create --name vpc-2 --subnet 10.0.2.0/24 --vlan 1002 --dhcp --dhcp-start 10.0.2.10
06:49:04 INF VPC created name=vpc-2
core@control-1 ~ $ kubectl fabric vpc attach --vpc-subnet vpc-1/default --connection server-01--mclag--leaf-01--leaf-02
06:49:24 INF VPCAttachment created name=vpc-1--default--server-01--mclag--leaf-01--leaf-02
core@control-1 ~ $ kubectl fabric vpc attach --vpc-subnet vpc-2/default --connection server-02--mclag--leaf-01--leaf-02
06:49:34 INF VPCAttachment created name=vpc-2--default--server-02--mclag--leaf-01--leaf-02
The VPC subnet should belong to an IPv4Namespace, the default one in the VLAB is 10.0.0.0/16:
After you created the VPCs and VPCAttachments, you can check the status of the agents to make sure that the requested configuration was applied to the switches:
core@control-1 ~ $ kubectl get agents
NAME ROLE DESCR APPLIED APPLIEDG CURRENTG VERSION
leaf-01 server-leaf VS-01 MCLAG 1 2m2s 5 5 v0.23.0
leaf-02 server-leaf VS-02 MCLAG 1 2m2s 4 4 v0.23.0
leaf-03 server-leaf VS-03 112s 5 5 v0.23.0
spine-01 spine VS-04 16m 3 3 v0.23.0
spine-02 spine VS-05 18m 4 4 v0.23.0
In this example, the values in columns APPLIED and APPLIEDG are equal which means that the requested configuration
has been applied.
Setting up networking on test servers
You can use hhfab vlab ssh on the host to SSH into the test servers and configure networking there. For example, for
both server-01 (MCLAG attached to both leaf-01 and leaf-02) we need to configure a bond with a VLAN on top of it
and for the server-05 (single-homed unbundled attached to leaf-03) we need to configure just a VLAn and they both
will get an IP address from the DHCP server. You can use the ip command to configure networking on the servers or use
the little helper preinstalled by Fabricator on test servers.
For server-01:
core@server-01 ~ $ hhnet cleanup
core@server-01 ~ $ hhnet bond 1001 enp2s1 enp2s2
10.0.1.10/24
core@server-01 ~ $ ip a
...
3: enp2s1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
link/ether 06:5a:e8:38:3b:ea brd ff:ff:ff:ff:ff:ff permaddr 0c:20:12:fe:01:01
4: enp2s2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
link/ether 06:5a:e8:38:3b:ea brd ff:ff:ff:ff:ff:ff permaddr 0c:20:12:fe:01:02
6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 06:5a:e8:38:3b:ea brd ff:ff:ff:ff:ff:ff
inet6 fe80::45a:e8ff:fe38:3bea/64 scope link
valid_lft forever preferred_lft forever
7: bond0.1001@bond0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 06:5a:e8:38:3b:ea brd ff:ff:ff:ff:ff:ff
inet 10.0.1.10/24 metric 1024 brd 10.0.1.255 scope global dynamic bond0.1001
valid_lft 86396sec preferred_lft 86396sec
inet6 fe80::45a:e8ff:fe38:3bea/64 scope link
valid_lft forever preferred_lft forever
And for server-02:
core@server-02 ~ $ hhnet cleanup
core@server-02 ~ $ hhnet bond 1002 enp2s1 enp2s2
10.0.2.10/24
core@server-02 ~ $ ip a
...
3: enp2s1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
link/ether 5e:10:b1:f7:d0:4c brd ff:ff:ff:ff:ff:ff permaddr 0c:20:12:fe:02:01
4: enp2s2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
link/ether 5e:10:b1:f7:d0:4c brd ff:ff:ff:ff:ff:ff permaddr 0c:20:12:fe:02:02
8: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 5e:10:b1:f7:d0:4c brd ff:ff:ff:ff:ff:ff
inet6 fe80::5c10:b1ff:fef7:d04c/64 scope link
valid_lft forever preferred_lft forever
9: bond0.1002@bond0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 5e:10:b1:f7:d0:4c brd ff:ff:ff:ff:ff:ff
inet 10.0.2.10/24 metric 1024 brd 10.0.2.255 scope global dynamic bond0.1002
valid_lft 86185sec preferred_lft 86185sec
inet6 fe80::5c10:b1ff:fef7:d04c/64 scope link
valid_lft forever preferred_lft forever
Testing connectivity before peering
You can test connectivity between the servers before peering the switches using the ping command:
core@server-01 ~ $ ping 10.0.2.10
PING 10.0.2.10 (10.0.2.10) 56(84) bytes of data.
From 10.0.1.1 icmp_seq=1 Destination Net Unreachable
From 10.0.1.1 icmp_seq=2 Destination Net Unreachable
From 10.0.1.1 icmp_seq=3 Destination Net Unreachable
^C
--- 10.0.2.10 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2003ms
core@server-02 ~ $ ping 10.0.1.10
PING 10.0.1.10 (10.0.1.10) 56(84) bytes of data.
From 10.0.2.1 icmp_seq=1 Destination Net Unreachable
From 10.0.2.1 icmp_seq=2 Destination Net Unreachable
From 10.0.2.1 icmp_seq=3 Destination Net Unreachable
^C
--- 10.0.1.10 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2004ms
Peering VPCs and testing connectivity
To enable connectivity between the VPCs, peer them using kubectl fabric vpc peer:
core@control-1 ~ $ kubectl fabric vpc peer --vpc vpc-1 --vpc vpc-2
07:04:58 INF VPCPeering created name=vpc-1--vpc-2
Make sure to wait until the peering is applied to the switches using kubectl get agents command. After that, you can
test connectivity between the servers again:
core@server-01 ~ $ ping 10.0.2.10
PING 10.0.2.10 (10.0.2.10) 56(84) bytes of data.
64 bytes from 10.0.2.10: icmp_seq=1 ttl=62 time=6.25 ms
64 bytes from 10.0.2.10: icmp_seq=2 ttl=62 time=7.60 ms
64 bytes from 10.0.2.10: icmp_seq=3 ttl=62 time=8.60 ms
^C
--- 10.0.2.10 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2004ms
rtt min/avg/max/mdev = 6.245/7.481/8.601/0.965 ms
core@server-02 ~ $ ping 10.0.1.10
PING 10.0.1.10 (10.0.1.10) 56(84) bytes of data.
64 bytes from 10.0.1.10: icmp_seq=1 ttl=62 time=5.44 ms
64 bytes from 10.0.1.10: icmp_seq=2 ttl=62 time=6.66 ms
64 bytes from 10.0.1.10: icmp_seq=3 ttl=62 time=4.49 ms
^C
--- 10.0.1.10 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2004ms
rtt min/avg/max/mdev = 4.489/5.529/6.656/0.886 ms
If you delete the VPC peering with kubectl delete applied to the relevant object and wait for the agent to apply the
configuration on the switches, you can observe that connectivity is lost again:
core@control-1 ~ $ kubectl delete vpcpeering/vpc-1--vpc-2
vpcpeering.vpc.githedgehog.com "vpc-1--vpc-2" deleted
core@server-01 ~ $ ping 10.0.2.10
PING 10.0.2.10 (10.0.2.10) 56(84) bytes of data.
From 10.0.1.1 icmp_seq=1 Destination Net Unreachable
From 10.0.1.1 icmp_seq=2 Destination Net Unreachable
From 10.0.1.1 icmp_seq=3 Destination Net Unreachable
^C
--- 10.0.2.10 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2004ms
You can see duplicate packets in the output of the ping command between some of the servers. This is expected
behavior and is caused by the limitations in the VLAB environment.
core@server-01 ~ $ ping 10.0.5.10
PING 10.0.5.10 (10.0.5.10) 56(84) bytes of data.
64 bytes from 10.0.5.10: icmp_seq=1 ttl=62 time=9.58 ms
64 bytes from 10.0.5.10: icmp_seq=1 ttl=62 time=9.58 ms (DUP!)
64 bytes from 10.0.5.10: icmp_seq=2 ttl=62 time=6.99 ms
64 bytes from 10.0.5.10: icmp_seq=2 ttl=62 time=6.99 ms (DUP!)
64 bytes from 10.0.5.10: icmp_seq=3 ttl=62 time=9.59 ms
64 bytes from 10.0.5.10: icmp_seq=3 ttl=62 time=9.60 ms (DUP!)
^C
--- 10.0.5.10 ping statistics ---
3 packets transmitted, 3 received, +3 duplicates, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 6.987/8.720/9.595/1.226 ms
Using VPCs with overlapping subnets
First, create a second IPv4Namespace with the same subnet as the default one:
core@control-1 ~ $ kubectl get ipns
NAME SUBNETS AGE
default ["10.0.0.0/16"] 24m
core@control-1 ~ $ cat <<EOF > ipns-2.yaml
apiVersion: vpc.githedgehog.com/v1alpha2
kind: IPv4Namespace
metadata:
name: ipns-2
namespace: default
spec:
subnets:
- 10.0.0.0/16
EOF
core@control-1 ~ $ kubectl apply -f ipns-2.yaml
ipv4namespace.vpc.githedgehog.com/ipns-2 created
core@control-1 ~ $ kubectl get ipns
NAME SUBNETS AGE
default ["10.0.0.0/16"] 30m
ipns-2 ["10.0.0.0/16"] 8s
Let's assume that vpc-1 already exists and is attached to server-01 (see Creating and attaching VPCs).
Now we can create vpc-3 with the same subnet as vpc-1 (but in the different IPv4Namespace) and attach it to the
server-03:
core@control-1 ~ $ cat <<EOF > vpc-3.yaml
apiVersion: vpc.githedgehog.com/v1alpha2
kind: VPC
metadata:
name: vpc-1
namespace: default
spec:
ipv4Namespace: ipns-2
subnets:
default:
dhcp:
enable: true
range:
start: 10.0.1.10
subnet: 10.0.1.0/24
vlan: "2001"
vlanNamespace: default
EOF
core@control-1 ~ $ kubectl apply -f vpc-3.yaml
At that point you can setup networking on server-03 the same as you did for server-01 and server-02 in
a previous section. Once you have configured networking, server-01 and
server-03 have IP addresses from the same subnets.
Created: December 22, 2023