VyOS High Availability Walkthrough

This document walks you through a complete HA setup of two VyOS machines. This design is based on a VM as the primary router, and a physical machine as a backup, using VRRP, BGP, OSPF and conntrack sharing.

The aim of this document is to walk you through setting everything up so you end up at a point where you can reboot any machine and not lose more than a few seconds worth of connectivity.

Design

This is based on a real life, in production design. One of the complex issues is ensuring you have redundant data INTO your network. We do this with a pair of Cisco Nexus switches, and using Virtual PortChannels that are spanned across them. This as an added bonus, also allows for complete switch failure without an outage. How you achieve this yourself is left as an exercise to the reader but our setup is documented here.

Walkthrough suggestion

The commit command is implied after every section. If you make an error, commit will warn you and you can fix it before getting too far into things. Please ensure you commit early and commit often.

If you are following through this document, it is strongly suggested you complete the entire document, ONLY doing the virtual router1 steps, and then come back and walk through it AGAIN on the backup hardware router.

This ensures you don’t go to fast, or miss a step. However, it will make your life easier to configure the fixed IP address and default route now on the hardware router.

Example Network

In this document, we have been allocated 203.0.113.0/24 by our upstream provider, which we are publishing on VLAN100.

They want us to establish a BGP session to their routers on 192.0.2.11 and 192.0.2.12 from our routers 192.0.2.21 and 192.0.2.22. They are AS 65550 and we are AS65551.

Our routers are going to have a floating IP address of 203.0.113.1, and use .2 and .3 as their fixed IPs.

We are going to use 10.200.201.0/24 for an ‘internal’ network on VLAN201.

When traffic is originated from the 10.200.201.0/24 network, it will be masqueraded to 203.0.113.1

For connection between sites, we are running a WireGuard link to two REMOTE routers, and using OSPF over those links to distribute routes. That remote site is expected to send traffic from anything in 10.201.0.0/16

VLANs

These are the vlans we wll be using:

  • 50: Upstream, using the 192.0.2.0/24 network allocated by them.
  • 100: ‘Public’ network, using our 203.0.113.0/24 network.
  • 201: ‘Internal’ network, using 10.200.201.0/24

Hardware

  • switch1 (Nexus 10gb Switch)
  • switch2 (Nexus 10gb Switch)
  • compute1 (VMware ESXi 6.5)
  • compute2 (VMware ESXi 6.5)
  • compute3 (VMware ESXi 6.5)
  • router2 (Random 1RU machine with 4 NICs)

Note that router1 is a VM that runs on one of the compute nodes.

Network Cabling

  • From Datacenter - This connects into port 1 on both switches, and is tagged as VLAN 50
  • Cisco VPC Crossconnect - Ports 39 and 40 bonded between each switch
  • Hardware Router - Port 8 of each switch
  • compute1 - Port 9 of each switch
  • compute2 - Port 10 of each switch
  • compute3 - Port 11 of each switch

This is ignoring the extra Out-of-band management networking, which should be on totally different switches, and a different feed into the rack, and is out of scope of this.

Note about VMware

Our implementation uses VMware’s Distributed Port Groups, which allows VMware to use LACP. This is a part of the ENTERPRISE licence, and is not available on a Free licence. If you are implementing this and do not have access to DPGs, you should not use VMware, and use some other virtualization platform instead.

Basic Setup (via console)

Create your router1 VM so it is able to withstand a VM Host failing, or a network link failing. Using VMware, this is achieved by enabling vSphere DRS, vSphere Availability, and creating a Distributed Port Group that uses LACP.

Many other Hypervisors do this, and I’m hoping that this document will be expanded to document how to do this for others.

Create an ‘All VLANs’ network group, that passes all trunked traffic through to the VM. Attach this network group to router1 as eth0.

VMware Note: You must DISABLE SECURITY on this Port group. Make sure that Promiscuous Mode, MAC address changes and Forged transmits are enabled. All of these will be done as part of failover.

Bonding on Hardware Router

Create a LACP bond on the hardware router. We are assuming that eth0 and eth1 are connected to port 8 on both switches, and that those ports are configured as a Port-Channel.

set interfaces bonding bond0 description 'Switch Port-Channel'
set interfaces bonding bond0 hash-policy 'layer2'
set interfaces bonding bond0 member interface 'eth0'
set interfaces bonding bond0 member interface 'eth1'
set interfaces bonding bond0 mode '802.3ad'

Assign external IP addresses

VLAN 100 and 201 will have floating IP addresses, but VLAN50 does not, as this is talking directly to upstream. Create our IP address on vlan50.

For the hardware router, replace eth0 with bond0. As (almost) every command is identical, this will not be specified unless different things need to be performed on different hosts.

set interfaces ethernet eth0 vif 50 address '192.0.2.21/24'

In this case, the hardware router has a different IP, so it would be

set interfaces ethernet bond0 vif 50 address '192.0.2.22/24'

Add (temporary) default route, and enable SSH

It is assumed that the routers provided by upstream are capable of acting as a default router. Add that as a static route, and enable SSH so you can now SSH into the routers, rather than using the console.

set protocols static route 0.0.0.0/0 next-hop 192.0.2.11
set service ssh
commit
save

At this point you should be able to SSH into both of them, and will no longer need access to the console (unless you break something!)

Configure Floating IPs

Now you can SSH into the routers, it makes it a lot easier to copy-and-paste configurations.

We need to set up the fixed and floating IPs.

VRRP Configuration

We are setting up VRRP so that it does NOT fail back when a machine returns into service, and it prioritizes router1 over router2.

Internal network 10.200.201.0/24

This has a floating IP address of 10.200.201.1, using virtual router ID 201. The difference between them is the interface name, hello-source-address, and peer-address.

router1

set interfaces ethernet eth0 vif 201 address 10.200.201.2/24
set high-availability vrrp group int hello-source-address '10.200.201.2'
set high-availability vrrp group int interface 'eth0.201'
set high-availability vrrp group int peer-address '10.200.201.3'
set high-availability vrrp group int no-preempt
set high-availability vrrp group int priority '200'
set high-availability vrrp group int virtual-address '10.200.201.1/24'
set high-availability vrrp group int vrid '201'

router2

set interfaces ethernet bond0 vif 201 address 10.200.201.3/24
set high-availability vrrp group int hello-source-address '10.200.201.3'
set high-availability vrrp group int interface 'bond0.201'
set high-availability vrrp group int peer-address '10.200.201.2'
set high-availability vrrp group int no-preempt
set high-availability vrrp group int priority '100'
set high-availability vrrp group int virtual-address '10.200.201.1/24'
set high-availability vrrp group int vrid '201'

Public network 203.0.113.0/24

This has a floating IP address of 203.0.113.1, using virtual router ID 113. The virtual router ID is just a random number between 1 and 254, and can be set to whatever you want. Best practices suggest you try to keep them unique enterprise-wide.

router1

set interfaces ethernet eth0 vif 100 address 203.0.113.2/24
set high-availability vrrp group public hello-source-address '203.0.113.2'
set high-availability vrrp group public interface 'eth0.100'
set high-availability vrrp group public peer-address '203.0.113.3'
set high-availability vrrp group public no-preempt
set high-availability vrrp group public priority '200'
set high-availability vrrp group public virtual-address '203.0.113.1/24'
set high-availability vrrp group public vrid '113'

router2

set interfaces ethernet bond0 vif 100 address 203.0.113.3/24
set high-availability vrrp group public hello-source-address '203.0.113.3'
set high-availability vrrp group public interface 'bond0.100'
set high-availability vrrp group public peer-address '203.0.113.2'
set high-availability vrrp group public no-preempt
set high-availability vrrp group public priority '100'
set high-availability vrrp group public virtual-address '203.0.113.1/24'
set high-availability vrrp group public vrid '113'

Create vrrp sync-group

The sync group is used to replicate connection tracking. It needs to be assigned to a random VRRP group, and we are creating a sync group called sync using the vrrp group int.

set high-availability vrrp sync-group sync member 'int'

Testing

At this point, you should be able to see both IP addresses when you run show interfaces, and show vrrp should show both interfaces in MASTER state (and SLAVE state on router2).

[email protected]:~$ show vrrp
Name      Interface      VRID  State    Last Transition
--------  -----------  ------  -------  -----------------
int       eth0.201        201  MASTER   100s
public    eth0.100        113  MASTER   200s
[email protected]:~$

You should be able to ping to and from all the IPs you have allocated.

NAT and conntrack-sync

Masquerade Traffic originating from 10.200.201.0/24 that is heading out the public interface. Note we explicitly exclude the primary upstream network so that BGP or OSPF traffic doesn’t accidentally get NAT’ed.

set nat source rule 10 destination address '!192.0.2.0/24'
set nat source rule 10 outbound-interface 'eth0.50'
set nat source rule 10 source address '10.200.201.0/24'
set nat source rule 10 translation address '203.0.113.1'

Configure conntrack-sync and disable helpers

Most conntrack modules cause more problems than they’re worth, especially in a complex network. Turn them off by default, and if you need to turn them on later, you can do so.

set system conntrack modules ftp disable
set system conntrack modules gre disable
set system conntrack modules nfs disable
set system conntrack modules pptp disable
set system conntrack modules sip disable
set system conntrack modules tftp disable

Now enable replication between nodes. Replace eth0.201 with bond0.201 on the hardware router.

set service conntrack-sync accept-protocol 'tcp,udp,icmp'
set service conntrack-sync event-listen-queue-size '8'
set service conntrack-sync failover-mechanism vrrp sync-group 'sync'
set service conntrack-sync interface eth0.201
set service conntrack-sync mcast-group '224.0.0.50'
set service conntrack-sync sync-queue-size '8'

Testing

The simplest way to test is to look at the connection tracking stats on the standby hardware router with the command show conntrack-sync statistics. The numbers should be very close to the numbers on the primary router.

When you have both routers up, you should be able to establish a connection from a NAT’ed machine out to the internet, reboot the active machine, and that connection should be preserved, and will not drop out.

OSPF Over WireGuard

Wireguard doesn’t have the concept of an up or down link, due to its design. This complicates AND simplifies using it for network transport, as for reliable state detection you need to use SOMETHING to detect when the link is down.

If you use a routing protocol itself, you solve two problems at once. This is only a basic example, and is provided as a starting point.

Configure Wireguard

There is plenty of instructions and documentation on setting up Wireguard. The only important thing you need to remember is to only use one WireGuard interface per OSPF connection.

We use small /30’s from 10.254.60/24 for the point-to-point links.

router1

Replace the 203.0.113.3 with whatever the other router’s IP address is.

set interfaces wireguard wg01 address '10.254.60.1/30'
set interfaces wireguard wg01 description 'router1-to-offsite1'
set interfaces wireguard wg01 ip ospf authentication md5 key-id 1 md5-key 'i360KoCwUGZvPq7e'
set interfaces wireguard wg01 ip ospf cost '11'
set interfaces wireguard wg01 ip ospf dead-interval '5'
set interfaces wireguard wg01 ip ospf hello-interval '1'
set interfaces wireguard wg01 ip ospf network 'point-to-point'
set interfaces wireguard wg01 ip ospf priority '1'
set interfaces wireguard wg01 ip ospf retransmit-interval '5'
set interfaces wireguard wg01 ip ospf transmit-delay '1'
set interfaces wireguard wg01 peer OFFSITE1 allowed-ips '0.0.0.0/0'
set interfaces wireguard wg01 peer OFFSITE1 endpoint '203.0.113.3:50001'
set interfaces wireguard wg01 peer OFFSITE1 persistent-keepalive '15'
set interfaces wireguard wg01 peer OFFSITE1 pubkey 'GEFMOWzAyau42/HwdwfXnrfHdIISQF8YHj35rOgSZ0o='
set interfaces wireguard wg01 port '50001'

offsite1

This is connecting back to the STATIC IP of router1, not the floating.

set interfaces wireguard wg01 address '10.254.60.2/30'
set interfaces wireguard wg01 description 'offsite1-to-router1'
set interfaces wireguard wg01 ip ospf authentication md5 key-id 1 md5-key 'i360KoCwUGZvPq7e'
set interfaces wireguard wg01 ip ospf cost '11'
set interfaces wireguard wg01 ip ospf dead-interval '5'
set interfaces wireguard wg01 ip ospf hello-interval '1'
set interfaces wireguard wg01 ip ospf network 'point-to-point'
set interfaces wireguard wg01 ip ospf priority '1'
set interfaces wireguard wg01 ip ospf retransmit-interval '5'
set interfaces wireguard wg01 ip ospf transmit-delay '1'
set interfaces wireguard wg01 peer ROUTER1 allowed-ips '0.0.0.0/0'
set interfaces wireguard wg01 peer ROUTER1 endpoint '192.0.2.21:50001'
set interfaces wireguard wg01 peer ROUTER1 persistent-keepalive '15'
set interfaces wireguard wg01 peer ROUTER1 pubkey 'CKwMV3ZaLntMule2Kd3G7UyVBR7zE8/qoZgLb82EE2Q='
set interfaces wireguard wg01 port '50001'

Create Export Filter

We only want to export the networks we know we should be exporting. Always whitelist your route filters, both importing and exporting. A good rule of thumb is ‘If you are not the default router for a network, don’t advertise it’. This means we explicitly do not want to advertise the 192.0.2.0/24 network (but do want to advertise 10.200.201.0 and 203.0.113.0, which we ARE the default route for). This filter is applied to redistribute connected. If we WERE to advertise it, the remote machines would see 192.0.2.21 available via their default route, establish the connection, and then OSPF would say ‘192.0.2.0/24 is available via this tunnel’, at which point the tunnel would break, OSPF would drop the routes, and then 192.0.2.0/24 would be reachable via default again. This is called ‘flapping’.

set policy access-list 150 description 'Outbound OSPF Redistribution'
set policy access-list 150 rule 10 action 'permit'
set policy access-list 150 rule 10 destination any
set policy access-list 150 rule 10 source inverse-mask '0.0.0.255'
set policy access-list 150 rule 10 source network '10.200.201.0'
set policy access-list 150 rule 20 action 'permit'
set policy access-list 150 rule 20 destination any
set policy access-list 150 rule 20 source inverse-mask '0.0.0.255'
set policy access-list 150 rule 20 source network '203.0.113.0'
set policy access-list 150 rule 100 action 'deny'
set policy access-list 150 rule 100 destination any
set policy access-list 150 rule 100 source any

Create Import Filter

We only want to import networks we know about. Our OSPF peer should only be advertising networks in the 10.201.0.0/16 range. Note that this is an INVERSE MATCH. You deny in access-list 100 to accept the route.

set policy access-list 100 description 'Inbound OSPF Routes from Peers'
set policy access-list 100 rule 10 action 'deny'
set policy access-list 100 rule 10 destination any
set policy access-list 100 rule 10 source inverse-mask '0.0.255.255'
set policy access-list 100 rule 10 source network '10.201.0.0'
set policy access-list 100 rule 100 action 'permit'
set policy access-list 100 rule 100 destination any
set policy access-list 100 rule 100 source any
set policy route-map PUBOSPF rule 100 action 'deny'
set policy route-map PUBOSPF rule 100 match ip address access-list '100'
set policy route-map PUBOSPF rule 500 action 'permit'

Enable OSPF

Every router must have a unique router-id. The ‘reference-bandwidth’ is used because when OSPF was originally designed, the idea of a link faster than 1gbit was unheard of, and it does not scale correctly.

set protocols ospf area 0.0.0.0 authentication 'md5'
set protocols ospf area 0.0.0.0 network '10.254.60.0/24'
set protocols ospf auto-cost reference-bandwidth '10000'
set protocols ospf log-adjacency-changes
set protocols ospf parameters abr-type 'cisco'
set protocols ospf parameters router-id '10.254.60.2'
set protocols ospf route-map PUBOSPF

Test OSPF

When you have enabled OSPF on both routers, you should be able to see each other with the command show ip ospf neighbour. The state must be ‘Full’ or ‘2-Way’, if it is not then there is a network connectivity issue between the hosts. This is often caused by NAT or MTU issues. You should not see any new routes (unless this is the second pass) in the output of show ip route

BGP

BGP is an extremely complex network protocol. An example is provided here. Note, again, router id’s must be unique.

router1

The redistribute ospf command is there purely as an example of how this can be expanded. In this walkthrough, it will be filtered by BGPOUT rule 10000, as it is not 203.0.113.0/24.

set policy prefix-list BGPOUT description 'BGP Export List'
set policy prefix-list BGPOUT rule 10 action 'deny'
set policy prefix-list BGPOUT rule 10 description 'Do not advertise short masks'
set policy prefix-list BGPOUT rule 10 ge '25'
set policy prefix-list BGPOUT rule 10 prefix '0.0.0.0/0'
set policy prefix-list BGPOUT rule 100 action 'permit'
set policy prefix-list BGPOUT rule 100 description 'Our network'
set policy prefix-list BGPOUT rule 100 prefix '203.0.113.0/24'
set policy prefix-list BGPOUT rule 10000 action 'deny'
set policy prefix-list BGPOUT rule 10000 prefix '0.0.0.0/0'
set policy route-map BGPOUT description 'BGP Export Filter'
set policy route-map BGPOUT rule 10 action 'permit'
set policy route-map BGPOUT rule 10 match ip address prefix-list 'BGPOUT'
set policy route-map BGPOUT rule 10000 action 'deny'
set policy route-map BGPPREPENDOUT description 'BGP Export Filter'
set policy route-map BGPPREPENDOUT rule 10 action 'permit'
set policy route-map BGPPREPENDOUT rule 10 set as-path-prepend '65551 65551 65551'
set policy route-map BGPPREPENDOUT rule 10 match ip address prefix-list 'BGPOUT'
set policy route-map BGPPREPENDOUT rule 10000 action 'deny'
set protocols bgp 65551 address-family ipv4-unicast network 192.0.2.0/24
set protocols bgp 65551 address-family ipv4-unicast redistribute connected metric '50'
set protocols bgp 65551 address-family ipv4-unicast redistribute ospf metric '50'
set protocols bgp 65551 neighbor 192.0.2.11 address-family ipv4-unicast route-map export 'BGPOUT'
set protocols bgp 65551 neighbor 192.0.2.11 address-family ipv4-unicast soft-reconfiguration inbound
set protocols bgp 65551 neighbor 192.0.2.11 remote-as '65550'
set protocols bgp 65551 neighbor 192.0.2.11 update-source '192.0.2.21'
set protocols bgp 65551 parameters router-id '192.0.2.21'

router2

This is identical, but you use the BGPPREPENDOUT route-map to advertise the route with a longer path.