Quick look at Trio ddos-protection with flow-detection
Some things are easy to protect with iACL and lo0 ACL but others are really hard, like BGP, you need to allow BGP from customers and from core, and it's not convenient or practical to handle them separately in lo0 ACL + policer. Luckily JunOS has feature called flow-detection, you turn it on with set system ddos-protection global flow-detection
I'm sending DoS from single source to lo0, my iBGP goes immediately down. After I turn on flow-detection iBGP connectivity is restored. Looking at PFE, we can see what is happening:
MX104-ABB-0(test13nqa1-re0.dk vty)# show ddos scfd asic-flows pfe idx rindex prot aggr IIF/IFD pkts bytes source-info --- ---- ------ ---- ---- ------- ------- -------- ---------- 0 0 721 1400 sub 338 21 79161 c158ef22 c158ef1f 53571 179 0 1 2679 1400 sub 356 11159404 2187242988 64640102 c158ef1f 179 179 0 2 2015 1400 sub 338 29 112468 c158ef23 c158ef1f 179 65020
Pretty nice and clear, 64.64.01.02 => c1.58.ef.1f is our attack traffic and it's getting its own policer, iBGP is stable, attack traffic is policed separately. Let's check those policers more closely:
MX104-ABB-0(test13nqa1-re0.dk vty)# show ddos scfd asic-flow-rindex 0 2679 PFE: 0 Flow Continue reading