rfp and fpr interfaces not updated after changing network MTU
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
neutron |
Fix Released
|
Medium
|
Brian Haley |
Bug Description
I have a tenant network attached to a router and external network, and some VMs with Floating IPs deployed. I updated the network MTU from 1500 to 1300 (just as a test, but try any other MTU), and restarted nova compute, ovs agent, l3-agent.
All interfaces (qvo/qvb/qbr, qr, dhcp taps, sg, fg, qg) got updated except for the rfp-fpr peer link between qrouter and fip namespace:
[root@dvr-
br-ex: flags=4163<
ens32: flags=4163<
ens34: flags=4163<
ens35: flags=4163<
ens34.1801: flags=4163<
lo: flags=73<
qbr05d85481-ca: flags=4163<
qbr147c3499-25: flags=4163<
qbrbf9399bf-17: flags=4163<
qbrf1ba8ee0-e1: flags=4163<
qvb05d85481-ca: flags=4419<
qvb147c3499-25: flags=4419<
qvbbf9399bf-17: flags=4419<
qvbf1ba8ee0-e1: flags=4419<
qvo05d85481-ca: flags=4419<
qvo147c3499-25: flags=4419<
qvobf9399bf-17: flags=4419<
qvof1ba8ee0-e1: flags=4419<
tap05d85481-ca: flags=4163<
tap147c3499-25: flags=4163<
tapbf9399bf-17: flags=4163<
tapf1ba8ee0-e1: flags=4163<
virbr0: flags=4099<
[root@dvr-
lo: flags=73<
qr-9f725d28-82: flags=4163<
qr-a9852f10-d1: flags=4163<
rfp-b57abb6d-9: flags=4163<
[root@dvr-
lo: flags=73<
tap8ecd0a51-63: flags=4163<
[root@dvr-
fg-a7668bc9-97: flags=4163<
fpr-b57abb6d-9: flags=4163<
lo: flags=73<
[root@dvr-
lo: flags=73<
qg-d69632ce-e4: flags=4163<
sg-83643ed0-34: flags=4163<
sg-9eac9eee-69: flags=4163<
VM taps are still at 1500, but will change if I powercycle VMs or migrate. rfp/fprs remain at 1500 and unsure of how to get their MTUs to update
I tested this on devstack and indeed when I was changing MTU for private network, values on qr- ports in router's namespace were updated.
When I was changing MTU on public network, qg- port in snat- namespace was also updated properly.
But in both cases MTU on rfp- and fpr- ports were not changed.
IMO it should be changed accordingly to MTU change for public network but I would like confirmation for that from some L3 experts like Brian or LIU Yulong :)