Solaris netstat : Understanding the output when displaying routing table By Devan

Solaris netstat : Understanding the output when displaying routing table

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.