I am experiencing flap issues on my Cisco 9300 devices. These are connected to 9200 access switches, creating redundancy with two core switches (9300). The access switches have two uplink ports, one connected to each core switch. I have reviewed the spanning-tree, port-channel, and trunk configurations and have not detected any inconsistencies. All devices are provisioned in DNA Center.
When executing a show mac address for the MAC, it is observed that it oscillates between ports 21 and 22. I also checked for multiple MAC addresses on an access port to identify any out-of-standard switches, but nothing was found. No physical loop was detected either.
witch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 52 C9200L-48P-4X 17.09.04a CAT9K_LITE_IOSXE INSTALL
cm_tr_p2c_cabecera1_9300#sh etherchannel summary
Flags: D - down P - bundled in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
U - in use f - failed to allocate aggregator
M - not in use, minimum links not met
u - unsuitable for bundling
w - waiting to be aggregated
d - default port
A - formed by Auto LAG
Number of channel-groups in use: 1
Number of aggregators: 1
Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
1 Po1(SU) PAgP Gi1/0/23(P) Gi1/0/24(P)
cm_tr_p2c_cabecera1_9300#
cm_tr_p2c_cabecera1_9300# sh int trunk
Port Mode Encapsulation Status Native vlan
Gi1/0/20 on 802.1q trunking 1
Gi1/0/21 on 802.1q trunking 1
Gi1/0/22 on 802.1q trunking 1
Te1/1/1 on 802.1q trunking 1
Po1 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi1/0/20 19,32,126,132
Gi1/0/21 19,32,126,132
Gi1/0/22 19,32,126,132
Te1/1/1 310,320
Po1 19,32,126,132
Port Vlans allowed and active in management domain
Gi1/0/20 19,32,126,132
Gi1/0/21 19,32,126,132
Gi1/0/22 19,32,126,132
Te1/1/1 310,320
Po1 19,32,126,132
Port Vlans in spanning tree forwarding state and not pruned
Gi1/0/20 19,32,126,132
Gi1/0/21 19,32,126,132
Gi1/0/22 19,32,126,132
Te1/1/1 310,320
Po1 19,32,126,132
cm_tr_p2c_cabecera1_9300#
cm_tr_p2c_cabecera1_9300# sh vl br
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Gi1/0/1, Gi1/0/2, Gi1/0/3, Gi1/0/4, Gi1/0/5, Gi1/0/6, Gi1/0/7, Gi1/0/8, Gi1/0/9, Gi1/0/10, Gi1/0/11, Gi1/0/12
Gi1/0/13, Gi1/0/14, Gi1/0/15, Gi1/0/16, Gi1/0/17, Gi1/0/18, Gi1/0/19, Te1/1/2, Te1/1/3, Te1/1/4, Te1/1/5
Te1/1/6, Te1/1/7, Te1/1/8, Ap1/0/1
19 Admin_y_Ospf active
32 Lan1 active
126 telefonia active
132 ToIP_P2C active
310 WAN_DATOS active
320 WAN_VOZ active
400 VLAN0400 active
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
cm_tr_p2c_cabecera1_9300#
cm_tr_p2c_cabecera1_9300# sh mac add ad c85a.cfa6.c721
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
32 c85a.cfa6.c721 DYNAMIC Gi1/0/22
Total Mac Addresses for this criterion: 1
cm_tr_p2c_cabecera1_9300# sh mac add ad c85a.cfa6.c721
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
32 c85a.cfa6.c721 DYNAMIC Gi1/0/21
Total Mac Addresses for this criterion: 1
cm_tr_p2c_cabecera1_9300# sh mac add ad c85a.cfa6.c721
