(feature change request) remove link-layer generated routes from netstat -r

[Nikos Vassiliadis]

On Thursday 23 February 2006 18:33, John Baldwin wrote:
> On Thursday 23 February 2006 02:56, Nikos Vassiliadis wrote:
> > On Thursday 23 February 2006 07:06, Eugene Grosbein wrote:
> > > On Wed, Feb 22, 2006 at 03:50:17PM +0200, Nikos Vassiliadis wrote:
> > > > netstat -r prints link-layer generated routes and many
> > > > times the output becomes somehow obscure. For
> > > > example:
> > > >
> > > > root at brad:0:/usr/home/src/FreeBSD-6/src/usr.bin/netstat# netstat
> > > > -ranfinet Routing tables
> > > >
> > > > Internet:
> > > > Destination        Gateway            Flags    Refs      Use  Netif
> > > > Expire default            10.1.1.244         UGS         0    31016
> > > > rl0 10.1.1/24          link#1             UC          0        0   
> > > > rl0 10.1.1.181         00:0f:1f:fb:02:f5  UHLW        1        0   
> > > > rl0 10.1.1.182         00:e0:fc:38:d4:40  UHLW        1        0   
> > > > rl0 10.1.1.183         00:e0:fc:65:07:fd  UHLW        1        0   
> > > > rl0 10.1.1.244         00:50:fc:fe:74:3b  UHLW        2        1   
> > > > rl0 10.1.1.254         00:0c:cf:70:50:06  UHLW        1        0   
> > > > rl0 127.0.0.1          127.0.0.1          UH          0     1117   
> > > > lo0 192.168.1          link#5             UC          0        0  
> > > > fxp0 192.168.1.25       00:05:5d:4d:19:58  UHLW        1        0  
> > > > fxp0 192.168.1.45       00:11:43:b6:a1:55  UHLW        1        0  
> > > > fxp0 192.168.1.71       00:0c:f1:b9:38:50  UHLW        1     1645  
> > > > fxp0 192.168.1.84       00:04:23:af:79:66  UHLW        1        0  
> > > > fxp0 192.168.1.112      00:30:4f:21:3b:8a  UHLW        1        0  
> > > > fxp0 192.168.1.196      00:07:e9:40:1f:c5  UHLW        1        0  
> > > > fxp0 192.168.1.199      00:e0:81:21:28:21  UHLW        1        0  
> > > > fxp0 192.168.1.200      00:30:4f:03:88:03  UHLW        1        0  
> > > > fxp0
> > > >
> > > >
> > > > when the information I was actually looking for is:
> > > >
> > > > root at brad:0:/usr/home/src/FreeBSD-6/src/usr.bin/netstat# netstat
> > > > -rnfinet Routing tables
> > > >
> > > > Internet:
> > > > Destination        Gateway            Flags    Refs      Use  Netif
> > > > Expire default            10.1.1.244         UGS         0    31016
> > > > rl0 10.1.1/24          link#1             UC          0        0   
> > > > rl0 127.0.0.1          127.0.0.1          UH          0     1117   
> > > > lo0 192.168.1          link#5             UC          0        0  
> > > > fxp0 root at brad:0:/usr/home/src/FreeBSD-6/src/usr.bin/netstat#
> > > >
> > > >
> > > > The attachment patch ("cvs diff -u -rHEAD route.c" generated) prints
> > > > link-layer generated routes when -a is specified and ignores them
> > > > the rest of the time.
> > > >
> > > > Thoughts? POLA violation?
> > >
> > > Just use:
> > >
> > > netstat -rn | awk '$3 !~ /L/ { print }'
> >
> > That's exactly the point Eugene, I don't want to find ways to filter it
> > out. It happens frequently. I didn't say it's difficult to remove it, I
> > just don't want it there all the time. That's why you can use -a to get
> > the old behavior.
>
> Using simple pipelines with awk and sed, etc. is the UN*X way though. 
> Instead of building all-singing all-dancing programs you build simpler
> utilities that you "glue" together to build more complex behavior.

I agree with you, but the UN*X way is also keeping high info-to-noise ratio.
Utilities tend to give very little output by default and switches must be used
to increase the verbosity. That's the usual with a few exceptions (ifconfig
comes to mind, defaults to -a (all) when in my opinion -u (up) would be a
better choice. Please change this:) )