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Story
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Resolution: Done-Errata
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Normal
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None
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nmstate-2.2.21-1.el9
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None
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1
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rhel-sst-network-management
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ssg_networking
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22
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1
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False
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Yes
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NMT - RHEL 8.10/9.4 DTM 18-20
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Pass
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None
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Enhancement
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Done
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None
What were you trying to do that didn't work?
I was trying to connect from one pod to another one in OpenShift using an additional network, but when the pods are in the same host they cannot connect.
The NetworkAttachmentDefinition is using a macvlan (default bridge mode) on top of a vlan defined in an nncp.
The investigation indicates that the issue is that the vlan is created with the "reorder_hdr" set to "off", preventing the vlan from redirecting packages between pods on the same host.
The VLAN was created with an nncp similar to this one:
apiVersion: nmstate.io/v1 kind: NodeNetworkConfigurationPolicy metadata: name: gorka spec: desiredState: interfaces: - name: enp6s0.102 description: testing VLAN using enp6s0 type: vlan state: up vlan: base-iface: eenp6s0 id: 102
And when we look at the interface we can see that <REORDER_HDR> is not there
$ ip -detail a show enp6s0.102
244: enp6s0.102@enp6s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 52:54:00:70:fa:d9 brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 0 maxmtu 65535
vlan protocol 802.1Q id 102 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
The issue stems from the default value when using the D-Bus API is disabling the reordering (unlike when creating things manually) and we don't have a way to change this value to enable it.
The default value of "vlan.flags" is described in the NetworkManager documentation and we can see it in the vlan that gets created:
$ sudo nmcli c show enp6s0.102|grep vlan connection.type: vlan vlan.parent: fe02f3e7-bb18-360e-b183-2c7f814f219d vlan.id: 102 vlan.flags: 0 (NONE) vlan.protocol: -- vlan.ingress-priority-map: -- vlan.egress-priority-map: --
The ask would be to either change the default or allowing passing of "vlan.flags" at the nncp level so that a macvlan on top of vlan allows pods within the same host to communicate with one another.
Please provide the package NVR for which bug is seen:
This was tried on an OpenShift local version 4.13.0 with the following versions:
handlerNmstateVersion: nmstatectl 2.2.12
hostNetworkManagerVersion: 1.42.2
How reproducible:
Always.
Steps to reproduce
- Create an nncp to create a vlan
- Create a nad to have a macvlan interface on top of the vlan
- Create a couple of pods on the same OpenShift host with that nad
Another way to reproduce it is creating the vlan with nncp and then manually creating 2 network namespaces, creating 2 macvlans on top of the vlan, assign one macvlan to each nw namespace, and then try to ping from one namespace to the other.
Expected results
One pod can ping the other using that interface IP address
Actual results
There is no connectivity between the 2 pods.
- blocks
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OSPRH-3286 [DEV] LVM support
- Closed
- is depended on by
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OSPRH-1382 Cinder LVM backend support
- Closed
- relates to
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OSPRH-387 octavia manager networking - implement a replacement for the o-hm0 mechanism
- Closed
- links to
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RHBA-2023:120000 nmstate bug fix and enhancement update
- mentioned on