Skip to content

Comments

[DNM] Test: SNAT traffic from advertised UDNs towards UDN enabled default services#2705

Closed
jcaamano wants to merge 55 commits intoopenshift:masterfrom
jcaamano:ds-udn-snat-kapi-dns-test
Closed

[DNM] Test: SNAT traffic from advertised UDNs towards UDN enabled default services#2705
jcaamano wants to merge 55 commits intoopenshift:masterfrom
jcaamano:ds-udn-snat-kapi-dns-test

Conversation

@jcaamano
Copy link
Contributor

@jcaamano jcaamano commented Aug 7, 2025

📑 Description

Fixes #

Additional Information for reviewers

✅ Checks

  • My code requires changes to the documentation
  • if so, I have updated the documentation as required
  • My code requires tests
  • if so, I have added and/or updated the tests as required
  • All the tests have passed in the CI

How to verify it

Lei Huang and others added 30 commits July 26, 2025 02:14
Update unit tests to check that the returned error contains the expected message,
not just that an error occurred. This ensures the renderer fails for the right reasons,
ensuring tests precisely validate failures.

Signed-off-by: Lei Huang <leih@nvidia.com>
Today when default network or UDN networks are
advertised using RAs the nodes also learn the
routes of other nodes' pod subnets in the cluster.

Example snippet of exposing a UDN network on
non-vrflite usecase:

root@ovn-worker2:/# ip r show table 1048
default via 172.18.0.1 dev breth0 mtu 1400
10.96.0.0/16 via 169.254.0.4 dev breth0 mtu 1400
10.244.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
10.244.2.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20
103.103.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
103.103.1.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20
169.254.0.3 via 203.203.1.1 dev ovn-k8s-mp12
169.254.0.34 dev ovn-k8s-mp12 mtu 1400
172.26.0.0/16 nhid 41 via 172.18.0.5 dev breth0 proto bgp metric 20
203.203.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
203.203.0.0/16 via 203.203.1.1 dev ovn-k8s-mp12
203.203.1.0/24 dev ovn-k8s-mp12 proto kernel scope link src 203.203.1.2
local 203.203.1.2 dev ovn-k8s-mp12 proto kernel scope host src 203.203.1.2
broadcast 203.203.1.255 dev ovn-k8s-mp12 proto kernel scope link src 203.203.1.2
203.203.2.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20

root@ovn-worker2:/# ip r show table 1046
default via 172.18.0.1 dev breth0 mtu 1400
10.96.0.0/16 via 169.254.0.4 dev breth0 mtu 1400
10.244.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
10.244.2.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20
103.103.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
103.103.0.0/16 via 103.103.2.1 dev ovn-k8s-mp11
103.103.1.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20
103.103.2.0/24 dev ovn-k8s-mp11 proto kernel scope link src 103.103.2.2
local 103.103.2.2 dev ovn-k8s-mp11 proto kernel scope host src 103.103.2.2
broadcast 103.103.2.255 dev ovn-k8s-mp11 proto kernel scope link src 103.103.2.2
169.254.0.3 via 103.103.2.1 dev ovn-k8s-mp11
169.254.0.32 dev ovn-k8s-mp11 mtu 1400
172.26.0.0/16 nhid 41 via 172.18.0.5 dev breth0 proto bgp metric 20
203.203.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
203.203.2.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20
root@ovn-worker2:/#

this happens because we import routes from the
default VRF:

      prefixes:
      - 103.103.0.0/24
      - 2014:100:200::/64
      - 2016:100:200::/64
      - 203.203.0.0/24
    - asn: 64512
      imports:
      - vrf: default
      vrf: mp11-udn-vrf
    - asn: 64512
      imports:
      - vrf: default
      vrf: mp12-udn-vrf
  nodeSelector:
    matchLabels:
      kubernetes.io/hostname: ovn-worker
  raw: {}

root@ovn-worker2:/# ip r
default via 172.18.0.1 dev breth0 mtu 1400
10.96.0.0/16 via 169.254.0.4 dev breth0 mtu 1400
10.244.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
10.244.2.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20
103.103.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
103.103.1.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20
169.254.0.3 via 203.203.1.1 dev ovn-k8s-mp12
169.254.0.34 dev ovn-k8s-mp12 mtu 1400
172.26.0.0/16 nhid 41 via 172.18.0.5 dev breth0 proto bgp metric 20
203.203.0.0/24 nhid 39 via 172.18.0.4 dev breth0 proto bgp metric 20
203.203.0.0/16 via 203.203.1.1 dev ovn-k8s-mp12
203.203.1.0/24 dev ovn-k8s-mp12 proto kernel scope link src 203.203.1.2
local 203.203.1.2 dev ovn-k8s-mp12 proto kernel scope host src 203.203.1.2
broadcast 203.203.1.255 dev ovn-k8s-mp12 proto kernel scope link src 203.203.1.2
203.203.2.0/24 nhid 40 via 172.18.0.3 dev breth0 proto bgp metric 20

which directly breaks UDN isolation.

In this commit we are going to remove the support for receiving routes. So
advertising routes will only advertise routes and we will no longer
make the nodes receive these routes. However in the future when we support
overlay-mode with BGP, we will need to re-add these routes and design
a better isolation model with UDNs within the cluster if that is
desired.

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
This is a temporary commit - we need a proper followup.
Please see ovn-kubernetes/ovn-kubernetes#5407
for details.

As of today all NATs created by OVN-Kubernetes are unique
using the existing 5 tuple algo in IsEquivalentNAT - uuid,
type of snat, logicalIP, logicalPort, externalIP, externalIDs.

So its OK to get rid of match. But its not the correct way to
fix this - in future we might have two NATs with all other
fields except match being the same.

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
This PR is adding SNAT for advertised
UDNs and CDN if the destination of the traffic
is towards other nodes in the cluster.

This is a design change for BGP from
before (where pod->node was not SNATed
and podIP was preserved).

For normal UDNs we have 2 SNATs:

L3 UDN SNATs:

1) this cSNAT is added to ovn_cluster_router
for LGW egress traffic and SGW KAPI/DNS traffic:

_uuid               : 5485a25f-7a83-4dc0-840c-bbfbd0784aad
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-green-network, "k8s.ovn.org/topology"=layer3}
external_ip         : "169.254.0.38"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "203.203.0.0/24"
logical_port        : rtos-cluster_udn_tenant.green.network_ovn-control-plane
match               : "eth.dst == 0a:58:cb:cb:00:02"
options             : {stateless="false"}
priority            : 0
type                : snat

2) this SNAT is added to GR for SGW egress traffic:

_uuid               : d85fd65f-e3f3-4d52-95f9-5f88c925aa5a
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-green-network, "k8s.ovn.org/topology"=layer3}
external_ip         : "169.254.0.37"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "203.203.0.0/16"
logical_port        : []
match               : ""
options             : {stateless="false"}
priority            : 0
type                : snat

for L2, we have the following two SNATs both on GR:

_uuid               : a4b9942f-ec1a-42ca-81d9-3e4885ff2470
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-blue-network, "k8s.ovn.org/topology"=layer2}
external_ip         : "169.254.0.36"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "93.93.0.0/16"
logical_port        : rtoj-GR_cluster_udn_tenant.blue.network_ovn-control-plane
match               : "eth.dst == 0a:58:5d:5d:00:02"
options             : {stateless="false"}
priority            : 0
type                : snat

and

_uuid               : 24164866-da95-4b6f-9c65-8b16fa202758
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-blue-network, "k8s.ovn.org/topology"=layer2}
external_ip         : "169.254.0.35"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "93.93.0.0/16"
logical_port        : []
match               : "outport == \"rtoe-GR_cluster_udn_tenant.blue.network_ovn-control-plane\""
options             : {stateless="false"}
priority            : 0
type                : snat

now with advertised networks these will change to:

_uuid               : a4b9942f-ec1a-42ca-81d9-3e4885ff2470
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-blue-network, "k8s.ovn.org/topology"=layer2}
external_ip         : "169.254.0.36"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "93.93.0.0/16"
logical_port        : rtoj-GR_cluster_udn_tenant.blue.network_ovn-control-plane
match               : "eth.dst == 0a:58:5d:5d:00:02 && (ip4.dst == $a712973235162149816)"
options             : {stateless="false"}
priority            : 0
type                : snat

_uuid               : 24164866-da95-4b6f-9c65-8b16fa202758
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-blue-network, "k8s.ovn.org/topology"=layer2}
external_ip         : "169.254.0.35"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "93.93.0.0/16"
logical_port        : []
match               : "outport == \"rtoe-GR_cluster_udn_tenant.blue.network_ovn-control-plane\" && ip4.dst == $a712973235162149816"
options             : {stateless="false"}
priority            : 0
type                : snat

_uuid               : d85fd65f-e3f3-4d52-95f9-5f88c925aa5a
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-green-network, "k8s.ovn.org/topology"=layer3}
external_ip         : "169.254.0.37"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "203.203.0.0/16"
logical_port        : []
match               : "ip4.dst == $a712973235162149816"
options             : {stateless="false"}
priority            : 0
type                : snat

_uuid               : 5485a25f-7a83-4dc0-840c-bbfbd0784aad
allowed_ext_ips     : []
exempted_ext_ips    : []
external_ids        : {"k8s.ovn.org/network"=cluster_udn_tenant-green-network, "k8s.ovn.org/topology"=layer3}
external_ip         : "169.254.0.38"
external_mac        : []
external_port_range : "32768-60999"
gateway_port        : []
logical_ip          : "203.203.0.0/24"
logical_port        : rtos-cluster_udn_tenant.green.network_ovn-control-plane
match               : "eth.dst == 0a:58:cb:cb:00:02 && (ip4.dst == $a712973235162149816)"
options             : {stateless="false"}
priority            : 0
type                : snat

so basically we add this extra match for destination IPs to SNAT to masqueradeIP for that UDN

note: with this PR we will break hardware offload for assymmetry traffix for BGP L2

As for the CDN, we have 1 SNAT with no matches on GR and that is being changed
to now have a cSNAT in case the default network is advertised.

NOTE: In -ds flag mode, the per-pod SNAT will have this match set.
NOTE2: For all deleteNAT scenarios we purposefully don't pass snat as a match criteria

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
Given that some traffic like pod->node and pod->nodeport
will be SNATed to nodeIP for UDNs, we will need iprules for both
masqueradeIP and nodeIP to be present when networks are
advertised. This is nothing complicated as keeping
the masqueradeIP dangling around doesn't hurt anything (I hope :))

so for pod->node it follows the normal UDN LGW egress traffic flow:

1) pod->switch->ovn_cluster_router
2) SNAT at the router to masIP
3) ovn_cluster_router->switch->mpX
4) goes out and then

reply coming from outside will hit these masqueradeIP rules to come
back in since we snated to masqueradeIP on the way out, so we need
both podsubnet and masqueradeIP rules for advertised networks

for all other traffic no SNATing is done

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
This commit is a prep-commit that converts
the LGW POSTROUTING chain rules from IPT
to NFT.
Why do we need to do this now?
It's because for BGP we want to use the PMTUD remote nodeIP
NFT sets to also do conditional masquerading in Local Gateway mode
for BGP when traffic leaves UDNs towards other nodes in the cluster
or other nodeports.
Given PMTUD rules are in NFT but the lgw and udn masquerade rules are
in IPT - we'd need to pick one to express all - since we want to
move to NFT, its better to go that route.

Below is how the rules look like.

        chain ovn-kube-local-gw-masq {
		comment "OVN local gateway masquerade"
		type nat hook postrouting priority srcnat; policy accept;
		ip saddr 169.254.0.1 masquerade
                ip6 saddr fd69::1 masquerade
		jump ovn-kube-pod-subnet-masq
		jump ovn-kube-udn-masq
	}

	chain ovn-kube-pod-subnet-masq {
		ip saddr 10.244.2.0/24 masquerade
                ip6 saddr fd00:10:244:1::/64 masquerade
	}

	chain ovn-kube-udn-masq {
		comment "OVN UDN masquerade"
                ip saddr != 169.254.0.0/29 ip daddr != 10.96.0.0/16 ip saddr 169.254.0.0/17 masquerade
                ip6 saddr != fd69::/125 ip daddr != fd00:10:96::/112 ip6 saddr fd69::/112 masquerade
	}

This commit was AI-Cursor-gemini/claude assissted
under my supervision/prompting/reviewing/back-forth iterations

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
let's reuse the pmtud address-set ips of the remote
nodes ips also for bgp advertised networks cSNAT

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
This commit is valid only for default networks
as mentioned in title. It's because unlike in
UDNs where we do cSNATs in OVN on router at the edge
before it leaves to node, for CDN everything happens
on the node side already - so we can leverage the
nodeIP masquerade bits.

if network is advertised:
	chain ovn-kube-pod-subnet-masq {
		ip saddr 10.244.2.0/24 ip daddr @remote-node-ips-v4 masquerade
		ip6 saddr fd00:10:244:3::/64 ip6 daddr @remote-node-ips-v6 masquerade
	}

else:

	chain ovn-kube-pod-subnet-masq {
		ip saddr 10.244.2.0/24 masquerade
                ip6 saddr fd00:10:244:3::/64 masquerade
	}

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
1) remove the l2 failure limitation since we now use nodeIPs
reply knows how to go back to src node since we have routes for that
2) add udn pod -> default network nodeport service (same and diff node)
3) add udn pod -> udn network nodeport service (same and diff node) - same network
4) add udn pod -> udn network nodeport service (same and diff node) - different network

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
In the previous commits we added SNATing to nodeIP
for the following traffic flows:

pod -> nodes
pod -> nodeports

when pods are part of advertised networks. Prior to
SNATing to nodeIPs they are SNATed at the ovn_cluster_router
to masqueradeIP before being sent into the host.

In commit ovn-kubernetes/ovn-kubernetes@75dd73f
we had converted all UDN flows that matched on masqueradeIP
as the source on breth0 for UDN pods to services traffic flow
to instead match on the podsubnets.

However given we have pod to node and pod to nodeport
traffic flows using masqueradeIP as the SNAT we need to
now re-add the masqueradeIP flows as well to ensure that
nodeports isolation between UDNs work correctly.

Before this commit:

In LGW/SGW flow is: UDN pod -> samenodeIP:nodeport in default network ->
SNATed to masqueradeIP of that UDN -> sent to host -> SNATed to clusterIP ->
hits the default flow in table=2 in br-ex:

 cookie=0xdeff105, duration=15690.053s, table=2, n_packets=0, n_bytes=0, idle_age=15690, priority=100 actions=mod_dl_dst:6e:4d:97:c0:3c:97,output:2

and sends to patch port of default network and this traffic
starts working when it shouldn't. (I mean eventually we want
this to work, see ovn-kubernetes/ovn-kubernetes#5410
but that's a future issue - outside my PR's scope)

In case of L3 UDN advertised pod -> nodeport service in default or other UDN network:
ovn-kubernetes/ovn-kubernetes@d63887e
is the commit where we added logic to match on srcIP of the traffic and
accordingly route it into the respective UDN patchports. So there we use
the masqueradeIP of a particular UDN to determine what the source of the traffic
was and route it into that particular UDN's patchport where it would backhole
if there was no matching clusterIP NAT entry there, and this is how
isolation was guaranteed.

Recently this was changed to a hard drop: ovn-kubernetes/ovn-kubernetes@dcc403c

For l2 topology the logic is same as above for clusterIPs but
for nodeports the GR itself drops the packets destined
towards the other networks as there is no LB entry present on
the GR as the destination IP is that of the router itself. That's how
isolation works there:

sample trace:
    next;
10. ls_out_apply_port_sec (northd.c:6039): 1, priority 0, uuid 2aa6ebd5
    output;
    /* output to "stor-cluster_udn_tenant.blue.network_ovn_layer2_switch", type "l3gateway" */

ingress(dp="GR_cluster_udn_tenant.blue.network_ovn-worker2", inport="rtos-cluster_udn_tenant.blue.network_ovn_layer2_switch")
-----------------------------------------------------------------------------------------------------------------------------
 0. lr_in_admission (northd.c:13232): eth.dst == 0a:58:64:41:00:03 && inport == "rtos-cluster_udn_tenant.blue.network_ovn_layer2_switch", priority 50, uuid 7f9af183
    reg9[1] = check_pkt_larger(1414);
    xreg0[0..47] = 0a:58:64:41:00:03;
    next;
 1. lr_in_lookup_neighbor (northd.c:13420): 1, priority 0, uuid d2672052
    reg9[2] = 1;
    next;
 2. lr_in_learn_neighbor (northd.c:13430): reg9[2] == 1 || reg9[3] == 0, priority 100, uuid 84ca0ef4
    mac_cache_use;
    next;
 3. lr_in_ip_input (northd.c:12824): ip4.dst == {172.18.0.4}, priority 60, uuid ea41c4e7
    drop;

Without this fix:

[FAIL] BGP: isolation between advertised networks Layer3 connectivity between networks [It] pod in the UDN should not be able to access a default network service

the above test will work in LGW when it should not work like is
the case for non-advertised UDNs.

This commit adds back the masqueradeIP flow as well for advertised
networks that drops all packets that didn't get routed on the higher
priority pkt_mark flows at 250.

when 2 UDNs are advertised:

this PR added back these two flows with masqueradeIP match:
cookie=0xdeff105, duration=127.593s, table=2, n_packets=0, n_bytes=0, priority=200,ip,nw_src=169.254.0.12 actions=drop
cookie=0xdeff105, duration=127.534s, table=2, n_packets=0, n_bytes=0, priority=200,ip,nw_src=169.254.0.14 actions=drop

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
Currently there are two bugs around using priority 100
for ovn-kube-local-gw-masq chain.

EgressIPs multinic rules are still in legacy IPT:

[0:0] -A OVN-KUBE-EGRESS-IP-MULTI-NIC -s 10.244.2.6/32 -o eth1 -j SNAT --to-source 10.10.10.105
[0:0] -A OVN-KUBE-EGRESS-IP-MULTI-NIC -s 10.244.0.3/32 -o eth1 -j SNAT --to-source 10.10.10.105
[1:60] -A OVN-KUBE-EGRESS-IP-MULTI-NIC -s 10.244.1.3/32 -o eth1 -j SNAT --to-source 10.10.10.105

and in netfilter the priority of NAT POSTROUTNG HOOK is 100
and not configurable. NF_IP_PRI_NAT_SRC in netfilter

and for NFTables its the same value 100 for NAT POSTROUTING hook
and its called "srcnat" in knftables and set to 100.

and this is the priority used by egress service feature since
that is already converted to NFT:

	chain egress-services {
		type nat hook postrouting priority srcnat; policy accept;
		meta mark 0x000003f0 return comment "DoNotSNAT"
		snat ip to ip saddr map @egress-service-snat-v4
		snat ip6 to ip6 saddr map @egress-service-snat-v6
	}

and now that we have converted POSTROUTING rules for
local-gw as well to NFT, those rules were already at priority 100.

Unlike IPT rules where we could jump to EIP and ESVC chains
before masquerade rules got hit, here those chains in NFT are
all parallel at same priority 100 and we don't know which one
will be hit first. Hence we need to change the priority of
ovn-kube-local-gw-masq so that EIP/ESVC rules are hit before
the default masquerade rules

W/O this change EIP/ESVC tests fail in CI

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
Prior to this change, the remote PMTUD address sets were only
considering the primary IP of the node.
While that was OK for PMTUD use case perhaps but for BGP
now that we reuse this address set in NFT we need to consider
all the IPs on the remote nodes.

So this commit changes code from using node internal IPs to
using the HostCIDRs annotation

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
When using the onModelUpdatesAllNonDefault() from
NAT updates, it wasn't updating match value when we
wanted to reset it. So when we went from advertised network
to non-advertised network, we were not changing the SNAT
match and hence traffic was still going out with podIP
instead of nodeIP.

This commit fixes that.

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
See ovn-kubernetes/ovn-kubernetes#5419 for details

But the traffic flow looks like this for Layer3(v4 and v6) and Layer2(v4):

pod in UDN A -> sameNodeIP:NodePort i.e 172.18.0.2:30724

pod (102.102.2.4)-> ovn-switch->ovn-cluster-router (SNAT to masqueradeIP 169.254.0.14)->
LRP send to mpX ->
in the host (IPTable DNAT from nodePort to clusterIP 10.96.96.233:8080)
send to breth0
breth0 flows reroute packet to UDN B's patchport
hits the GR of UDNB and DNATs from clusterIP to backend pod that lives on another node (103.103.1.5) at the same time SNAT to joinIP in
OVN router i.e 100.65.0.4
reponse comes back from remote pod
and then we see ARP requests trying to understand how to reach the masqueradeIP of the other network which makes total sense - so reply fails

NetworkB doesn't know how to reach back to NetworkA's masqueradeIP which is the srcIP.

root@ovn-control-plane:/# tcpdump -i any -nneev port 36363 or port 30724 or host 102.102.2.4 or host 169.254.0.14 or host 100.65.0.4
tcpdump: data link type LINUX_SLL2
tcpdump: listening on any, link-type LINUX_SLL2 (Linux cooked v2), snapshot length 262144 bytes
08:55:14.083364 865a53b516350_3 P   ifindex 19 0a:58:66:66:02:04 ethertype IPv4 (0x0800), length 80: (tos 0x0, ttl 64, id 53100, offset 0, flags [DF], proto TCP (6), length 60)
    102.102.2.4.42720 > 172.18.0.2.30724: Flags [S], cksum 0x14ad (incorrect -> 0x5e6c), seq 432663101, win 65280, options [mss 1360,sackOK,TS val 1239378349 ecr 0,nop,wscale 7], length 0
08:55:14.084049 ovn-k8s-mp2 In  ifindex 14 0a:58:66:66:02:01 ethertype IPv4 (0x0800), length 80: (tos 0x0, ttl 63, id 53100, offset 0, flags [DF], proto TCP (6), length 60)
    169.254.0.14.42826 > 172.18.0.2.30724: Flags [S], cksum 0x1c60 (correct), seq 432663101, win 65280, options [mss 1360,sackOK,TS val 1239378349 ecr 0,nop,wscale 7], length 0
08:55:14.084069 breth0 Out ifindex 6 6a:ed:17:fb:28:bd ethertype IPv4 (0x0800), length 80: (tos 0x0, ttl 62, id 53100, offset 0, flags [DF], proto TCP (6), length 60)
    169.254.0.14.42826 > 10.96.96.233.8080: Flags [S], cksum 0xb59f (correct), seq 432663101, win 65280, options [mss 1360,sackOK,TS val 1239378349 ecr 0,nop,wscale 7], length 0
08:55:14.084470 genev_sys_6081 Out ifindex 7 0a:58:64:58:00:04 ethertype IPv4 (0x0800), length 80: (tos 0x0, ttl 60, id 53100, offset 0, flags [DF], proto TCP (6), length 60)
    100.65.0.4.42826 > 103.103.1.5.8080: Flags [S], cksum 0xfe43 (correct), seq 432663101, win 65280, options [mss 1360,sackOK,TS val 1239378349 ecr 0,nop,wscale 7], length 0
08:55:14.085494 genev_sys_6081 P   ifindex 7 0a:58:64:58:00:02 ethertype IPv4 (0x0800), length 80: (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto TCP (6), length 60)
    103.103.1.5.8080 > 100.65.0.4.42826: Flags [S.], cksum 0x1f4f (correct), seq 3390013464, ack 432663102, win 64704, options [mss 1360,sackOK,TS val 1866737591 ecr 1239378349,nop,wscale 7], length 0
08:55:14.086130 eth0  Out ifindex 2 6a:ed:17:fb:28:bd ethertype ARP (0x0806), length 48: Ethernet (len 6), IPv4 (len 4), Request who-has 169.254.0.14 tell 169.254.0.15, length 28
08:55:14.086172 breth0 B   ifindex 6 6a:ed:17:fb:28:bd ethertype ARP (0x0806), length 48: Ethernet (len 6), IPv4 (len 4), Request who-has 169.254.0.14 tell 169.254.0.15, length 28
08:55:15.100558 genev_sys_6081 P   ifindex 7 0a:58:64:58:00:02 ethertype IPv4 (0x0800), length 80: (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto TCP (6), length 60)
    103.103.1.5.8080 > 100.65.0.4.42826: Flags [S.], cksum 0xccdf (incorrect -> 0x1b57), seq 3390013464, ack 432663102, win 64704, options [mss 1360,sackOK,TS val 1866738607 ecr 1239378349,nop,wscale 7], length 0
08:55:15.101090 eth0  Out ifindex 2 6a:ed:17:fb:28:bd ethertype ARP (0x0806), length 48: Ethernet (len 6), IPv4 (len 4), Request who-has 169.254.0.14 tell 169.254.0.15, length 28
08:55:15.101124 breth0 B   ifindex 6 6a:ed:17:fb:28:bd ethertype ARP (0x0806), length 48: Ethernet (len 6), IPv4 (len 4), Request who-has 169.254.0.14 tell 169.254.0.15, length 28

^ its the same for Layer3 v6 as well and same for Layer2 v4 ^^

but Layer2 v6 is weird thanks to:

// cookie=0xdeff105, duration=173.245s, table=1, n_packets=0, n_bytes=0, idle_age=173, priority=14,icmp6,icmp_type=134 actions=FLOOD
// cookie=0xdeff105, duration=173.245s, table=1, n_packets=8, n_bytes=640, idle_age=4, priority=14,icmp6,icmp_type=136 actions=FLOOD

these two flows on breth0 - these seem to  be flooding the NDP requests between the GR's of all networks somehow and v6 works.
So test is acknowledging this inconsistency and calling this out.

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
Makes this EMEA/US friendly.

Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
The "pre assigned port net ids" feature requires a NAD for the `default`
network to be provisioned. This commit pre-provisions that NAD whenever
the feature - EnableCustomNetworkConfig - is enabled, upon starting the
cluster manager.

Signed-off-by: Miguel Duarte Barroso <mdbarroso@redhat.com>
…-vms-with-ip-requests

udn, pre assigned port net ids: provision the default net NAD CR
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
UDN Isolation with BGP: Remove support for receiving advertised routes from remote nodes
chore: Update libovsdb bindings to ovn 25.03
Signed-off-by: nithyar <nithyar@nvidia.com>
We need to bump it to allow NSE with both ipam claims reference and
IPRequest.

Signed-off-by: Enrique Llorente <ellorent@redhat.com>
Pin the 'containernetworking/cni' library dependency to v1.2.3.
Version 1.3.0 introduced a breaking change where a new MarshalJSON
function in the CNI library causes it to ignore custom OVN-K fields
within 'nad.spec.config', leading to parsing failures.

Signed-off-by: Enrique Llorente <ellorent@redhat.com>
Signed-off-by: Enrique Llorente <ellorent@redhat.com>
Signed-off-by: Enrique Llorente <ellorent@redhat.com>
cathy-zhou and others added 14 commits August 1, 2025 17:42
Recent commit fd5e791 reintroduce the flow update error that was
fixed by commit 0054273: when gateway accelerated interface is used.

When gateway accelerated interface is used, we noticed the error
messages 'gateway_shared_intf.go:392] Unable to get port list from
bridge. ... failed to get list of ports on bridge "enp1s0f0v0":, stderr:
"ovs-ofctl: enp1s0f0v0 is not a bridge or a socket\n" ...'.

Signed-off-by: Yun Zhou <yunz@nvidia.com>
Signed-off-by: Tullio Sebastiani <tsebasti@redhat.com>
Allow configuring static IP and MAC with primary UDNs.
Fixes #5328

Signed-off-by: Ihar Hrachyshka <ihrachyshka@nvidia.com>
docs: remove dead link to topology google document
make fedora-image target already depends on go-controller. We are
wasting cycles building the same thing twice.

Signed-off-by: Ihar Hrachyshka <ihrachyshka@nvidia.com>
Signed-off-by: Surya Seetharaman <suryaseetharaman.9@gmail.com>
UDN: verify specific error messages in NAD rendering unit tests
kind.sh: Don't build go-controller twice
@openshift-merge-robot openshift-merge-robot added the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Aug 7, 2025
@openshift-ci openshift-ci bot requested review from kyrtapz and tssurya August 7, 2025 15:08
@openshift-ci
Copy link
Contributor

openshift-ci bot commented Aug 7, 2025

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jcaamano

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details Needs approval from an approver in each of these files:

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

@openshift-ci openshift-ci bot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Aug 7, 2025
…dns-test

Signed-off-by: Jaime Caamaño Ruiz <jcaamano@redhat.com>
This reverts commit bcd0656.
Just as we currently do with traffic towards nodes.

Specifically this allows for networks advertised with a VRF-Lite
configuration with a subnet overlap to reach these services. Otherwise
the return path could hit an ip rule corresponding to a different
advertised network forwarding it to an inappropriate destination.

Signed-off-by: Jaime Caamaño Ruiz <jcaamano@redhat.com>
@jcaamano jcaamano force-pushed the ds-udn-snat-kapi-dns-test branch from f7b7426 to 109ffc3 Compare August 7, 2025 15:46
@openshift-merge-robot openshift-merge-robot removed the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Aug 7, 2025
@jcaamano
Copy link
Contributor Author

jcaamano commented Aug 8, 2025

/retest

@openshift-ci
Copy link
Contributor

openshift-ci bot commented Aug 8, 2025

@jcaamano: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name Commit Details Required Rerun command
ci/prow/e2e-aws-ovn-hypershift-conformance-techpreview 109ffc3 link false /test e2e-aws-ovn-hypershift-conformance-techpreview
ci/prow/e2e-gcp-ovn 109ffc3 link true /test e2e-gcp-ovn
ci/prow/lint 109ffc3 link true /test lint
ci/prow/okd-scos-e2e-aws-ovn 109ffc3 link false /test okd-scos-e2e-aws-ovn
ci/prow/e2e-azure-ovn-upgrade 109ffc3 link true /test e2e-azure-ovn-upgrade
ci/prow/qe-perfscale-aws-ovn-small-udn-density-churn-l3 109ffc3 link false /test qe-perfscale-aws-ovn-small-udn-density-churn-l3
ci/prow/e2e-aws-ovn-hypershift-kubevirt 109ffc3 link false /test e2e-aws-ovn-hypershift-kubevirt
ci/prow/4.20-upgrade-from-stable-4.19-e2e-gcp-ovn-rt-upgrade 109ffc3 link true /test 4.20-upgrade-from-stable-4.19-e2e-gcp-ovn-rt-upgrade
ci/prow/security 109ffc3 link false /test security

Full PR test history. Your PR dashboard.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

approved Indicates a PR has been approved by an approver from all required OWNERS files.

Projects

None yet

Development

Successfully merging this pull request may close these issues.