Re: Filtering routes from IS-IS

"DEFAULT-TO-ISIS" is simply another policy that I'm using to inject a default route into ISIS. For reference here is the policy:

[edit]
lab@mx104-edge# show policy-options policy-statement DEFAULT-TO-ISIS 
term 1 {
    from {
        protocol aggregate;
        route-filter 0.0.0.0/0 exact;
    }
    then accept;
}

We can see the default route is present on the downstream device:

lab@srx-vpn> show route protocol isis 

inet.0: 7 destinations, 7 routes (7 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

0.0.0.0/0          *[IS-IS/165] 2w0d 21:22:28, metric 30
                    > to 137.221.196.5 via ge-0/0/0.0
137.221.196.0/30   *[IS-IS/18] 2w0d 21:22:38, metric 20> to 137.221.196.5 via ge-0/0/0.0

Let's now remove the policy leaving only the isis-filter policy we created previously:

[edit]
lab@mx104-edge# show protocols isis 
export isis-filter;
level 1 disable;
interface ge-0/0/1.0 {
    point-to-point;
}
interface lo0.0 {
    passive;
}

Checking on the downstream device we can now only see a single prefix is received:

lab@srx-vpn> show route protocol isis    

inet.0: 6 destinations, 6 routes (6 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

137.221.196.0/30   *[IS-IS/18] 2w0d 21:24:57, metric 20
                    > to 137.221.196.5 via ge-0/0/0.0

I hope this is now clear