th3architect/cldemo-config-routing

Flatfiles for setting up OSPF and BGP on Cumulus Linux

Demo Routing Configurations

This Github repository contains the configuration files necessary for setting up Layer 3 routing on a CLOS topology using Cumulus Linux and Quagga on the Reference Topology. Eight protocols are included:

• OSPF Numbered
• OSPF Unnumbered
• BGP Numbered
• BGP Unnumbered
• OSPF Numbered with IPv6
• OSPF Unnumbered with IPv6
• BGP Numbered with IPv6
• BGP Unnumbered with IPv6

The flatfiles in this repository will set up a Layer 3 routing fabric between the leafs and spines, and will configure a Layer 2 bridge on each leaf top-of-rack switch for the servers in that rack. Servers access other servers in the same rack with one hop across the leaf top-of-rack, and access servers in other racks via one of the spine switches. A helper script named push-config.py is available to quickly deploy the flatfiles to the devices in the network, but you could just as easily copy and paste them by hand or incorporate them into an automation tool instead.

This demo and these configurations are written to be used with the cldemo-vagrant reference topology.

Quickstart: Run the demo

(This assumes you are running Ansible 1.9.4 and Vagrant 1.8.4 on your host.)

git clone https://github.com/cumulusnetworks/cldemo-vagrant
cd cldemo-vagrant
vagrant up oob-mgmt-server oob-mgmt-switch leaf01 leaf02 spine01 spine02 server01 server02
vagrant ssh oob-mgmt-server
sudo su - cumulus
git clone https://github.com/cumulusnetworks/cldemo-config-routing
cd cldemo-config-routing
sudo ln -s  /home/cumulus/cldemo-config-routing /var/www/cldemo-config-routing
python pushconfig.py bgp-unnumbered leaf01,leaf02,spine01,spine02,server01,server02
ssh server01
ping 172.16.2.101

Topology

This demo runs on a spine-leaf topology with two single-attached hosts. The helper script push-config.py requires an out-of-band management network that provides access to eth0 on all of the in-band devices.

     +------------+       +------------+
     | spine01    |       | spine02    |
     |            |       |            |
     +------------+       +------------+
     swp1 |    swp2 \   / swp1    | swp2
          |           X           |
    swp51 |   swp52 /   \ swp51   | swp52
     +------------+       +------------+
     | leaf01     |       | leaf02     |
     |            |       |            |
     +------------+       +------------+
     swp1 |                       | swp2
          |                       |
     eth1 |                       | eth2
     +------------+       +------------+
     | server01   |       | server02   |
     |            |       |            |
     +------------+       +------------+

Using the Helper Script

The push-config.py helper script deploys the configuration to the in-band network by downloading the files from the out-of-band management server. This requires a web server to be installed on the out-of-band server and passwordless login and sudo to be enabled on the in-band devices, both of which are done for you if you used cldemo-vagrant to provision your topology. The demo repository needs to be linked in the management server's /var/www/ directory:

vagrant ssh oob-mgmt-server
sudo su - cumulus
git clone https://github.com/cumulusnetworks/cldemo-config-routing
cd cldemo-config-routing
sudo ln -s  /home/cumulus/cldemo-config-routing /var/www/cldemo-config-routing

After setting up the repo, you can now use push-config.py! This script will log in to each device, download the files, and reboot the device.

python pushconfig.py <demo_name> leaf01,leaf02,spine01,spine02,server01,server02

Verifying Routing

Running the demo is easiest with two terminal windows open. One window will log into server01 and ping server02's IP address. The second window will be used to deploy new configuration on the switches.

In terminal 1

vagrant ssh oob-mgmt-server
sudo su - cumulus
cd cldemo-config-routing
python pushconfig.py bgp-unnumbered leaf01,leaf02,spine01,spine02,server01,server02

In terminal 2

vagrant ssh oob-mgmt-server
sudo su - cumulus
ssh server01
ping 172.16.2.101

In terminal 1

python pushconfig.py ospf-unnumbered leaf01,leaf02,spine01,spine02
# wait and watch connectivity drop and then come back
python pushconfig.py bgp-numbered leaf01,leaf02,spine01,spine02
# again
python pushconfig.py bgp-unnumbered-ipv6 leaf01,leaf02,spine01,spine02,server01,server02
# this will reboot server01, so you'll need to log back in in terminal 2

Verify High Availability

Using a routing protocol such as BGP or OSPF means that as long as one spine is still running, the network will automatically learn a new route and keep the fabric connected. This means that you can do rolling upgrades one spine at a time without incurring any downtime.

In terminal 1

vagrant ssh oob-mgmt-server
sudo su - cumulus
cd cldemo-config-routing
python pushconfig.py bgp-unnumbered leaf01,leaf02,spine01,spine02,server01,server02

In terminal 2

vagrant ssh oob-mgmt-server
sudo su - cumulus
ssh server01
ping 172.16.2.101

In terminal 3

vagrant destroy -f spine01
# note that the pings may hiccup a bit, but will keep going
vagrant destroy -f spine02
# now pings will totally fail
vagrant up spine01 spine02

In terminal 1

python pushconfig.py bgp-unnumbered spine01,spine02
# watch Terminal 2, and pings will return

Using Quagga Dry Runs for Syntax Checking

You can use Quagga's dry run functionality to check the syntax of Quagga configuration without applying the changes.

vtysh -f Quagga.conf --dryrun

The syntax of all of the Quagga.conf files in this repository can be verified using the following line in bash.

 for i in `find  | grep Quagga.conf`; do vtysh -f $i --dryrun; done ;