It is sometimes necessary to suppress the IST subnet when redistributing direct into ISIS on the cluster routers.

ip prefix-list “ist” 10.199.1.0/30 id 1 ge 30 le 30

route-map “suppress-ist” 1
no permit
enable
match network “ist”
route-map “suppress-ist” 2
permit
enable
exit

router isis
redistribute direct
redistribute direct route-map “suppress-ist”
redistribute direct enable
exit

isis apply redistribute direct