Recently ran into an issue on an ACX evo platform that caused random routing protocols to intermittently drop.
We found that the DDoS (quick side tangent on why there are a number of other possible names for this feature, that DDoS does not feel like the right fit) thresholds were increased well past default. After some time with JTAC debugging, we found that the below commands were helpful in identifying host-path congestion which was the ultimate culprit for our issue.
Some level of dropped packets may be normal, especially with reconvergence.
root@redacted> start shell pfe network fpc0
root@redacted:pfe> show host-path ddos all-policers
Host Path Ddos Policers:
Group Policer Id BWidth Burst P Q Ena Rcvd Packets Drops Rate(pps) States Scfd Flows
ppp aggregate 0x0400 4000 1024 1 - on 0 0 0 ok off 0
ppp unclassified 0x0401 500 512 0 2 on 0 0 0 ok off 0
ppp lcp 0x0402 3000 1024 1 3 on 0 0 0 ok off 0
ppp authentication 0x0403 1000 512 1 3 on 0 0 0 ok off 0
ppp ipcp 0x0404 1000 512 2 3 on 0 0 0 ok off 0
root@redacted:pfe> show evo-pfemand host pkt-stats
------ ------ ------------- --------- --------------- --------------- ----------- --------------- ---------------------------
UNIT CMICQ Pkt Pkt_Rate Bytes Drp Pkts DrpPktsRate DrpBytes Proto(s)
------ ------ ------------- --------- --------------- --------------- ----------- --------------- ---------------------------
0 200 237033 28 31445861 0 0 0 recv-nh
0 201 882 0 56448 0 0 0 arp
0 202 8610 0 2853590 0 0 0 l2hi-pri/lacp, lldp, lfm, pvstp, stp, esmc
0 203 1290357 86 685037558 0 0 0 l3hi-pri/bgp,isis,ldp,ospf,rip,rsvp
0 204 32373 0 6359115 0 0 0 Mcast/igmp,pim
0 205 0 0 0 0 0 0 l2pt
0 206 28663 0 38877487 2977340 0 4055081029 unknown-mc
0 207 1054369 112 1415898840 306061012 30586 416845750015 ttl-excep
0 208 16 0 1150 0 0 0 resolve
0 209 0 0 0 0 0 0 bcast
0 210 0 0 0 0 0 0 l2pt-rw-uni
0 211 14310 0 1246476 0 0 0 l3low-pri/nd
0 212 0 0 0 0 0 0 local-nh
0 213 606228 66 55122496 0 0 0 rxq-bfd,bfdv6
0 214 0 0 0 0 0 0 rxq-cfm
0 215 0 0 0 0 0 0 rxq-vrrp
0 216 7223 0 1438000 19158 0 3979939 nh-reject
0 217 0 0 0 0 0 0 CpuMtuExpCore0
0 218 0 0 0 0 0 0 CpuMtuExpCore1
0 219 0 0 0 0 0 0 sample-source
0 220 0 0 0 0 0 0 sample-jflow
0 221 5 0 792 0 0 0 CpuDebug
0 222 2116 0 169461 0 0 0 CpuIpOption
0 223 0 0 0 0 0 0 netrounds
0 224 291 0 29274 0 0 0 rxq-dhcp
0 225 0 0 0 0 0 0 mpls-alert
0 226 168 0 221436 0 0 0 discard
0 227 0 0 0 0 0 0 overlay
0 228 0 0 0 0 0 0 ptp
0 229 108 0 14256 0 0 0 inline-bfd-punt
0 231 0 0 0 0 0 0 inline-ccm-rxq
root@redacted:pfe> show host-path ports
Name State Tx-Packets Tx-Rate(pps) Rx-Packets Rx-Rate(pps) Drop-Packets Drop-Rate(pps)
===================================================================================================================
fp0 READY 1451694 249 2569855 399 3152 0
pktin0 READY 0 0 0 0 0 0
ptp0 READY 0 0 0 0 0 0
sflow0 READY 0 0 0 0 0 0
cp0 READY 1723430 286 1432375 246 0 0
jflow0 READY 0 0 0 0 0 0
am0 READY 132 0 1 0 0 0
ppm0 READY 464660 64 464719 64 0 0