Synchronize O365 routes to an IOS-XE router using Guest Shell

This Guest Shell script uses Microsoft O365 Webservice to get routing information of Office365 cloud. It can be used to automatically create static routes for a dedicated Internet link. So Office365 traffic will use the link and all the remaining traffic will be routed using a default route via a different link. It can be used as an alternative to ExpressRoute. The generated static routes can be also used to bypass a firewall or proxy for Office365 traffic.

Guest Shell configuration

IOS configuration see https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/prog/configuration/1611/b_1611_programmability_cg/guest_shell.html https://community.cisco.com/t5/developer-general-blogs/introducing-python-and-guest-shell-on-ios-xe-16-5/ba-p/3661394

iox
!
interface VirtualPortGroup0
 ip address 192.168.250.1 255.255.255.0
!
app-hosting appid guestshell
 app-vnic gateway0 virtualportgroup 0 guest-interface 0
  guest-ipaddress 192.168.250.2 netmask 255.255.255.0
 app-default-gateway 192.168.250.1 guest-interface 0
 name-server0 192.168.21.50
 start

VirtualPortGroup0 can have ip nat inside with proper additional configuration to provide NAT/PAT for the Guest Shell container.

Installation

1. start guest shell guestshell run bash
2. install git sudo yum install git
3. install Python virtualenv sudo yum install python-virtualenv
4. install script git clone https://github.com/JardaMartan/o365-route.git
5. cd o365-route
6. create Python virtual environment virtualenv venv --system-site-packages
7. switch to Python virtual environment source venv/bin/activate
8. install required packages pip install -r requirements.txt
9. edit the config.py file, set at least next_hops to match your next hop IPs. These next hops will be used in static routes generated by the script.
10. run script in interactive mode python o365_manage_route.py -i46

Script parameters

usage: o365_manage_route.py [-h] [-i] [-4] [-6] [-v VRF]

optional arguments:
  -h, --help         show this help message and exit
  -i, --interactive  Run in interactive mode
  -4, --ipv4         Check IPv4 routing information (default yes)
  -6, --ipv6         Check IPv6 routing information (default no)
  -v VRF, --vrf VRF  VRF name

Automated run using EEM

EEM configuration to run every minute

event manager applet o365route
 event timer cron cron-entry "* * * * *"
 action 0.1 cli command "enable"
 action 1.0 syslog msg "O365 manage route script start"
 action 2.0 cli command "guestshell run ./o365-route/venv/bin/python ./o365-route/o365_manage_route.py -46"
 action 3.0 syslog msg "O365 manage route script end"

Remove routes from configuration

1. run script in interactive mode python -i o365_manage_route.py -i
2. run test procedure o365_networks, test_nets, cfg_nets = test_parsing()
3. remove IPv4 and IPv6 routes remove_routes(o365_networks["ipv4"], 4), remove_routes(o365_networks["ipv6"], 6)
4. do not forget to save configuration

for VRF-based configuration (VRF "vp" in this case) do:

1. python -i o365_manage_route.py -i -v vp
2. o365_networks, test_nets, cfg_nets = test_parsing(vrf="vp")
3. remove_routes(o365_networks["ipv4"], 4, vrf="vp")
4. remove_routes(o365_networks["ipv6"], 6, vrf="vp")