openstack/ovn-bgp-agent
Code Issues Proposed changes

Update EVPN Mode documentation

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Change-Id: Icce2edbff9ba75cd288328de71d2c28963355880
This commit is contained in:
Luis Tomas Bolivar 2021-10-04 13:44:46 +02:00
parent 67d16f3009
commit d701467eb8
2 changed files with 24 additions and 10 deletions
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34
doc/source/contributor/evpn_mode_design.rst
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@ -314,23 +314,37 @@ To do that it needs to:
'''
3. Connect EVPN to OVN overlay so that traffic can be redirected from the node
to the OVN virtual networking. It needs to:
to the OVN virtual networking. It needs to connect the VRF to the OVS
provider bridge:
- Attach the VRF device to the OVS provider bridge (e.g., br-ex)
- Create veth device and attach one end to the OVS provider bridge, and the
other to the vrf:
.. code-block:: ini
ovs-vsctl add-port br-ex vrf-1001
ip link add veth-vrf type veth peer name veth-ovs
ovs-vsctl add-port br-ex veth-ovs
ip link set veth-vrf master vrf-1001
ip link set up dev veth-ovs
ip link set up dev veth-vrf
- Or the equivalent steps (vlan device) for the vlan provider network cases:
.. code-block:: ini
ovs-vsctl add-port br-vlan br-vlan-1001 tag=ID -- set interface br-vlan-1001 type=internal
ip link set br-vlan-1001 up
ip link set br-vlan-1001 master vrf-1001
- Add route on the VRF routing table for both the router gateway port IP
and the subnet CIDR so that the traffic is redirected to the OVS provider
bridge (e.g., br-ex)
bridge (e.g., br-ex) through the veth/vlan device
.. code-block:: ini
$ ip route show vrf vrf-1001
10.0.0.0/26 via 172.24.4.146 dev br-ex
172.24.4.146 dev br-ex scope link
10.0.0.0/26 via 172.24.4.146 dev veth-vrf-1001|br-vlan-1001
172.24.4.146 dev veth-vrf-1001|br-vlan-1001 scope link
4. Add needed OVS flows into the OVS provider bridge (e.g., br-ex) to redirect
the traffic back from OVN to the proper VRF, based on the subnet CIDR and
@ -338,7 +352,7 @@ To do that it needs to:
.. code-block:: ini
$ ovs-ofctl add-flow br-ex cookie=0x3e7,priority=1000,ip,in_port=1,dl_src:ROUTER_GATEWAY_PORT_MAC,nw_src=SUBNET_CIDR, actions=mod_dl_dst:BR_EX_MAC,output=VRF_PORT
$ ovs-ofctl add-flow br-ex cookie=0x3e7,priority=1000,ip,in_port=1,dl_src:ROUTER_GATEWAY_PORT_MAC,nw_src=SUBNET_CIDR, actions=mod_dl_dst:VETH|VLAN_MAC,output=VETH|VLAN_PORT
5. Add IPs to expose to VRF associated dummy device. This interface is only
used for the purpose of exposing the IPs, but not meant to receive the
@ -423,14 +437,14 @@ default routing table (action=NORMAL). To that end, the next rule is added:
.. code-block:: ini
cookie=0x3e6, duration=4.141s, table=0, n_packets=0, n_bytes=0, priority=1000,ip,in_port="patch-provnet-c",dl_src=fa:16:3e:b7:cc:47,nw_src=20.0.0.0/24 actions=mod_dl_dst:1e:8b:ac:5d:98:4a,output:"vrf-101"
cookie=0x3e6, duration=4.141s, table=0, n_packets=0, n_bytes=0, priority=1000,ip,in_port="patch-provnet-c",dl_src=fa:16:3e:b7:cc:47,nw_src=20.0.0.0/24 actions=mod_dl_dst:1e:8b:ac:5d:98:4a,output:"veth-ovs-101"
It matches the traffic coming from the router gateway port (cr-lrp port) from
br-int (in_port="patch-provnet-c"), with the MAC address of the router gateway
port (dl_src=fa:16:3e:b7:cc:47) and from the exposed network (nw_src=20.0.0.0/24).
For that case it changes the MAC by the br-ex device one
For that case it changes the MAC by the veth-vrf-101 device one
(mod_dl_dst:1e:8b:ac:5d:98:4a), and redirect the traffic to the vrf device
(output:"vrf-101").
through the veth/vlan device (output:"veth-ovs-101").
Agent deployment