Management interface dropping packets

[LimaSupport]

Hi,

My monitoring system is detecting packet loss on my panorama device. When pinging the DG there is no packet loss. When checked the interface stats on the cli I can see the below.

admin@MANPANORAMA01(primary-active)> show interface management

-------------------------------------------------------------------------------
Name: Management Interface
Link status:
Runtime link speed/duplex/state: 100/full/up
Configured link speed/duplex/state: auto/auto/auto
MAC address:
Port MAC address 3c:ec:ef:55:38:46

Ip address: 192.168.20.21
Netmask: 255.255.254.0
Default gateway: 192.168.20.1
Ipv6 address: unknown
Ipv6 link local address: fe80::3eec:efff:fe55:3846/64
Ipv6 default gateway:
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
Logical interface counters:
-------------------------------------------------------------------------------
bytes received 19514555673572
bytes transmitted 13800146722446
packets received 17142368823
packets transmitted 15211441301
receive errors 0
transmit errors 0
receive packets dropped 821
transmit packets dropped 0
multicast packets received 5
-------------------------------------------------------------------------------

What could be causing packet loss on this interface?

[TomYoung]

Hi @LimaSupport ,

That is a tough one.  Most traffic dropped on the management interface is supposed to be dropped.  For example, a Cisco switch could be sending CDP packets.  Other layer 2 protocols could also be dropped.  I see that you have IPv6 configured.  So, it is probably not IPv6.  You could have your Permitted IP Addresses https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClovCAC configured and these packets do not come from an allowed source.  I think the only way to know for sure is to (at the same time) do a packet capture of transmitted packets on the next hop device and received packets on the management interface https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-admin/monitoring/take-packet-captures/take-a-pac... and compare to see which packets are missing from the Panorama capture.

The drops are most likely benign and not causing negative impact.  If you really want to know, you can do the packet captures.

Thanks,

Tom