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

[Giorgos Keramidas]

On 2006-02-23 12:14, Gary Corcoran <gcorcoran at rcn.com> wrote:
>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.
>
> Yes, when you want do do something "complicated", which doesn't belong
> in a single program, that's the way.  But IMO that doesn't apply here.
> I agree with Nikos.  He just wants to limit the often-useless (to most
> users) output which is *already* in the program.  Just providing a
> simple command line option to get back the full output, if ever
> needed, seems like a good, simple solution, to make things easier for
> us poor humans to scan. :)

How about making the new behavior non-default, i.e. toggled by a -s
switch to the netstat -r command?

        % netstat -rs

Then 's' can stand for 'short' output, and everyone can experiment with
the new feature.  Then, after a couple of minor releases, if we find
that this is a feature that is very often used, we can make it the
default.

- Giorgos