I was curious to see how *nix based operating systems generate routing tables and found that netstat -rn parses out from /proc/net/route. Viewing my /proc/net/route is something attune to:Iface  Destination  Gateway  Flags  RegCnt Use  Metric  Mask      MTU  Window  IRTTeth0   00000000     0101A8C0  0003  0      0    0       00000000  0    0       0Running a normal netstat -rn, I get the following:Destination  Gateway       Genmask  Flags  MSS  Window  irtt IFace0.0.0.0      192.168.1.1   0.0.0.0  UG       0       0     0 eth0For the most part, I understand what I'm seeing. I just want to understand how the Flags are determined. For example, how does the value 0003 map to UG (interface is up and is a gateway).Could someone point me in the right direction?Thanks.
How is *Nix parsing Netstat -rn (routing table) Flags?
netstat