In Vlan interface with below configuration the input queue gets filled when pumped with IPv6 traffic. All the packets after that gets dropped. The queue doesn't gets clear even when traffic is stopped, what could be the reason.
Also this happens only when ipv6 dhcp server dhcp-lite rapid-commit is configured on vlan interface
323.abc-3850-3#show interfaces vlan 201
Vlan201 is up, line protocol is up
Hardware is Ethernet SVI, address is 7aab.74a7.554b (bia 70d3.79a7.524c)
Internet address is 10.21.11.12/24
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not supported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:52:58, output 00:00:38, output hang never
Last clearing of "show interface" counters 00:52:12
Input queue: 15001/15000/2801330/104 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 995000 bits/sec, 1011 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
configuration on vlan 201
interface Vlan201
description NewManagement
ip flow monitor IPv4_NETFLOW input
ip address 10.21.11.12 255.255.255.0
ip helper-address 10.21.13.7
ip helper-address 10.13.14.1
ip pim sparse-dense-mode
ip cgmp
ip ospf message-digest-key 5 md5 <removed>
ipv6 nd prefix 2625:11A:5004:201::/64
ipv6 nd other-config-flag
ipv6 nd router-preference High
ipv6 nd ra dns server 3680:15B:1014:4::5
ipv6 nd ra dns server 3680:15B:1004:203::4
ipv6 dhcp server dhcp-lite rapid-commit
hold-queue 15000 in
