u/futschikat0

▲ 8 r/Arista

High CPU usage caused by VVTEP misconfiguration. How do I fix it?

We are quiet new to Arista and currently having this setup and use L3 VXLAN over MLAG:

After moving some SVI from our old network to Arista, we noticed an increase in CPU load to about 80-90%.

MLAG domain 1: LEAF-DC1-01, LEAF-DC1-02

interface Loopback1

ip address 100.64.1.1/32

ip address 100.64.1.100/32 secondary

ip virtual-router mac-address 00:1c:72:00:00:11

interface Vxlan1

vxlan source-interface Loopback1

vxlan virtual-router encapsulation mac-address mlag-system-id

vxlan udp-port 4789

vxlan vlan 1 vni 20001

vxlan vlan 2 vni 20002

vxlan vlan 3 vni 20003

MLAG domain 2: LEAF-DC2-01, LEAF-DC2-02

interface Loopback1

ip address 100.64.2.1/32

ip address 100.64.2.100/32 secondary

ip virtual-router mac-address 00:1c:72:00:00:11

interface Vxlan1

vxlan source-interface Loopback1

vxlan virtual-router encapsulation mac-address mlag-system-id

vxlan udp-port 4789

vxlan vlan 1 vni 20001

vxlan vlan 2 vni 20002

vxlan vlan 3 vni 20003

So the TAC figured out that the high CPU usage was because different VVTEP-IPs on each MLAG which cause loops on ARP sync. Which means we have to change this in MLAG domain 2 so that VVTEP matches the one in MLAG domain 1:

interface Loopback1

no ip address 100.64.2.100/32 secondary

ip address 100.64.1.100/32 secondary

Does anyone know how this will affect traffic?

Also is it neccessary to add

vxlan vtep flood

to interface vxlan 1? How would it look like? Like this?

MLAG domain 1: LEAF-DC1-01, LEAF-DC1-02

interface Vxlan1

vxlan vtep flood 100.64.2.1, 100.64.2.100

MLAG domain 2: LEAF-DC2-01, LEAF-DC2-02

interface Vxlan1

vxlan vtep flood 100.64.1.1, 100.64.2.100

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u/futschikat0 — 7 days ago