The post describes the meaning of the flags that are displayed in the routing tables when you use the netstat command.
Sample output:
# netstat -rn Routing Table: Destination Gateway Flags Ref Use Interface -------------------- -------------------- ----- ----- ----- --------- 127.0.0.1 127.0.0.1 UH 021220517 lo0 192.9.200.0 207.82.202.188 UG 0 93 192.9.200.0 207.82.202.65 UG 0 0 205.163.59.0 207.82.202.188 UG 0 24729 207.82.203.0 207.82.202.188 UG 0 29053 205.163.209.0 207.82.202.188 UG 0 27 207.82.202.128 207.82.202.129 U 2 9377 le1 207.82.202.64 207.82.202.66 U 2 496 qe0 192.112.65.0 192.112.65.10 U 3 1601 le0 224.0.0.0 192.112.65.10 U 3 0 le0 default 207.82.202.65 UG 0 152449
The Flags indicate: U - Up (The route is up) G - Gateway (The route is via a remote Router/Gateway) H - Host (The destination of the route is a specific host)
Entries with the U flag only, are routes to networks, via a gateway physically local to this host, (also displayed on all multicast routes).
You may also see a D flag. This flag indicates whether a route was created dynamically by an ICMP redirect, (this flag appears for Host routes only).
In Solaris 10, if you use the -a option with netstat you may see these additional flags:
A - Address Resolution B - Broadcast Address L - Local address for the host
In Solaris 11, if the -a option is specified, there will be routing entries with the following flags:
b Broadcast addresses. C Clones interface host route entries for on-link destinations. L Local addresses for the host.