This Article explains the reason for SSH, ICMP, VRRP, DHCP packet drops when huge multicast traffic received on EX2300.
Customer may notice the SSH, ICMP, DHCP, VRRP, etc drops during huge amount of multicast traffic receiving on EX2300.
TFXPC0(SW1 vty)# show halp-pkt pkt-stats
PKT TX STATS:
tx_req : 161528
tx_success : 163579
tx_l2cookie_found : 18
tx_l2token_lookup_success : 8
tx_arr_req : 163567
tx_arr_success : 163567
tx_with_tx_pbmp : 161321
tx_with_no_tx_pbmp : 2258
tx_pkt_proc_nobypass_mode : 207
tx_pkt_proc_bypass_mode : 161321
tx_pkt_reinsert_bcast : 207
PKT RX STATS:
rx_req : 7585696
rx_success : 7583645
rx_buf_alloc : 7586640
rx_pkt_duplicated : 10
rx_pkt_ipv4 : 7583194
rx_pkt_stp_inserted : 2051
rx_pkt_igmp_query : 10
rx_pkt_mc_unreg_q_full : 33
rx_pkt_mc_unreg_enqueued : 7421941
rx_pkt_vxlan_not_found_encap_pkt : 15171082
rx_pkt_mc_throttle_drop : 1889266
RX PER QUEUE STATS:
rx queue 3 : rxq_req 7583184 rxq_success 7583184
rx queue 5 : rxq_req 310 rxq_success 310
rx queue 6 : rxq_req 2202 rxq_success 151
Max pkt delay 1163 msec thread pid 39
poll mode: 1 max poll interval: 20 msec
MMU Flush Drop:
TFXPC0(SW1 vty)#
BCM.0> show c cpu
ING_NIV_RFVT.cpu0 : 1,781 +171
PERQ_PKT(3).cpu0 : 7,146,811 +1,041,878 501/s
PERQ_PKT(5).cpu0 : 305 +264
PERQ_BYTE(3).cpu0 : 492,108,908 +76,965,742 34,073/s
PERQ_BYTE(5).cpu0 : 20,708 +17,920
PERQ_DROP_PKT_EGR(3).cpu0 : 1,230,543,924 +16,732,535 9,524/s
BCM.0>
As per the internal PR-1469184, the behavior is expected as EX2300 has limited number of queues. Since ICMP, SSH, DHCP, VRRP and unknown multicast packets etc share the same queue, packets are dropped when unknown multicast packets are sent at higher rate. Below are workarounds mentioned in the PR.
TFXPC0(SW1 vty)# show halp-pkt hostpath-cfgs
RXQ Parameters
------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------------------------------
Idx Qid TTP prio Qlen QPrio MaxRate BurstSz Intr DMACH SchMode WRRwt ResBuf ShrPool ShrThrsh Q Name
0 6 4 0 0 0 0 1 1 0 0 0 0 0 rxq-bpdu
1 7 5 0 0 0 0 1 1 0 0 0 0 0 rxq-vc-ctrl
2 5 4 0 0 0 0 1 1 0 0 0 0 0 rxq-ntp
3 6 4 0 0 0 0 1 1 0 0 0 0 0 rxq-bfd
4 4 4 0 1 0 0 0 2 0 0 0 0 0 rxq-isis
5 0 4 0 0 0 0 1 2 0 0 0 0 0 rxq-fc
6 5 4 0 1 0 0 0 2 0 0 0 0 0 rxq-pim-ctrl
7 4 3 0 1 0 0 0 2 0 0 0 0 0 rxq-ospf-hello
8 5 3 0 1 0 0 0 2 0 0 0 0 0 rxq-pim-data-dhcp
9 5 3 0 1 0 0 0 2 0 0 0 0 0 rxq-arp-ndp
10 5 3 0 1 0 0 0 2 0 0 0 0 0 rxq-igmp-mld
11 0 3 0 1 0 0 0 2 0 0 0 0 0 rxq-fip-snoop
12 4 3 0 1 0 0 0 2 0 0 0 0 0 rxq-isis-rip-ul2mc
13 5 3 0 1 0 0 0 2 0 0 0 0 0 rxq-bgp-ldp-rsvp
14 3 2 0 1 0 0 0 2 0 0 0 0 0 rxq-ucast-switch
15 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-ipmc-miss
16 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-urpf-fail
17 3 2 0 0 0 0 1 3 0 0 0 0 0 rxq-flow
18 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-martian-addr
19 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-starg-data-icl
20 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-ucastsw-nhop
21 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-icmp
22 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-l3dest_miss
23 2 2 0 1 0 0 0 3 0 0 0 0 0 rxq-resolve
24 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-ipmc-rsvd
25 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-dos-attack
26 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-dhcp
27 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-vfp
28 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-filter-match
29 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-default
30 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-ip-option
31 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-ttl-mtuerror
32 1 2 0 1 0 0 0 3 0 0 0 0 0 rxq-sample-dest
33 1 2 0 1 0 0 0 3 0 0 0 0 0 rxq-sample-source
34 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-vc-ipc-udp
35 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-local-nh
36 0 2 0 1 0 0 0 3 0 0 0 0 0 rxq-vxlan-miss-l2-pkt
37 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-ipmc
38 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-l2mov
39 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-encapHiGigHdrerror
40 3 4 0 0 0 0 1 3 0 0 0 0 0 rxq-l2cpu
41 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-highdrerror
42 3 2 0 1 0 0 0 3 0 0 0 0 0 rxq-bcast
43 0 2 0 1 0 0 0 3 0 0 0 0 0 rxq-misc
https://www.juniper.net/content/dam/www/assets/datasheets/us/en/switches/ex2300-ethernet-switch-datasheet.pdf