Need to know the clear differences between RE protection and DDOS protection in Juniper MX. Both are used to save routing engine from depletion of resources. As mentioned in Juniper MX series book , policer called from an input filter on the loopback interface is downloaded to the Trio PFE where it is executed before any DDoS policier functionality.
With that being said , we can save the routing engine resources from depletion (which occurs for example due to icmp flood attack , snmp queries flooding , IP-fragments etc) using only protect re filter applied in inbound direction at loopback interface using filters and policiers , so then
why in addition to RE filter DDOS protection comes into picture when protecting the routing engine?
Are there any issues that are not handled by RE filter but handled by DDOS protection very well or put in another way
Whats the main reason behind using DDOS protection in addition to protect RE filter
If possible , please share detailed answer.