IRB interfaces with incoming traffic does respect the flowspec rules, both for firewall and redirection.

MX config
set interfaces ae2 unit 200 apply-groups-except TEMPLATE-INTERFACE-L3
set interfaces ae2 unit 200 encapsulation vlan-bridge

set bridge-domains VL200 interface ae2.200
set bridge-domains VL200 routing-interface irb.200

set interfaces irb unit 200 family inet rpf-check
set interfaces irb unit 200 family inet address 192.168.163.99/29 vrrp-group 0 virtual-address 192.168.163.97
set interfaces irb unit 200 family inet address 192.168.163.99/29 vrrp-group 0 priority 20
set interfaces irb unit 200 family inet address 192.168.163.99/29 vrrp-group 0 accept-data
set interfaces irb unit 200 family inet address 192.168.163.99/29 vrrp-group 1 virtual-address 192.168.163.98
set interfaces irb unit 200 family inet address 192.168.163.99/29 vrrp-group 1 priority 20
set interfaces irb unit 200 family inet address 192.168.163.99/29 vrrp-group 1 accept-data
set interfaces irb unit 200 family inet6 address 2804:11dc:0:2xx::xx/64

 
show configuration routing-options flow | display set 
set routing-options flow interface-group 1
set routing-options flow interface-group exclude
set routing-options flow route 172.16.1.71/32 match destination 172.16.1.71/32
set routing-options flow route 172.16.1.71/32 then discard
set routing-options flow term-order standard 

When removing the Irb.200 interface and have straight unit 0 on the xe ports the discard is happening correctly.

In LMEM Ctx , mesh group and interface-group overlap.
Hence we cannot support this feature.

NPC2(agenttwins vty)# show  jnh contexts  0x32
36 [Interface Group/8(bits) offset=region0/0x190, key:0x32/0] 
50 [Mesh group id/7(bits) offset=region0/0x191, key:0x32/1] <<< 7 bits of Meshgroup overlap with lsb of Interface group.

In older chip sets too there were overlap of these 2 fields in the Rewrite bytes of the fab header.

Interface-group is not supported for IRB.

Product limitation