BGP Example

Policy definition:

# Create policy
set policy route-map setmet rule 2 action 'permit'
set policy route-map setmet rule 2 set as-path-prepend '2 2 2'

# Apply policy to BGP
set protocols bgp local-as 1
set protocols bgp neighbor 203.0.113.2 address-family ipv4-unicast route-map import 'setmet'
set protocols bgp neighbor 203.0.113.2 address-family ipv4-unicast soft-reconfiguration 'inbound'

Using ‘soft-reconfiguration’ we get the policy update without bouncing the neighbor.

Routes learned before routing policy applied:

vyos@vos1:~$ show ip bgp
BGP table version is 0, local router ID is 192.168.56.101
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 198.51.100.3/32   203.0.113.2           1             0 2 i  < Path

Total number of prefixes 1

Routes learned after routing policy applied:

vyos@vos1:~$ show ip bgp
BGP table version is 0, local router ID is 192.168.56.101
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 198.51.100.3/32   203.0.113.2           1             0 2 2 2 2 i

Total number of prefixes 1
vyos@vos1:~$

You now see the longer AS path.

Transparent Proxy

The following example will show how VyOS can be used to redirect web traffic to an external transparent proxy:

set policy route FILTER-WEB rule 1000 destination port 80
set policy route FILTER-WEB rule 1000 protocol tcp
set policy route FILTER-WEB rule 1000 set table 100

This creates a route policy called FILTER-WEB with one rule to set the routing table for matching traffic (TCP port 80) to table ID 100 instead of the default routing table.

To create routing table 100 and add a new default gateway to be used by traffic matching our route policy:

set protocols static table 100 route 0.0.0.0/0 next-hop 10.255.0.2

This can be confirmed using the show ip route table 100 operational command.

Finally, to apply the policy route to ingress traffic on our LAN interface, we use:

set interfaces ethernet eth1 policy route FILTER-WEB