how to figure out which device a given IFB is connected to

how to figure out which device a given IFB is connected to

[Sebastian Moeller]

Hi All,

I hope I am directing this to the correct mailing list, otherwise please excuse the distraction… 

I am trying to figure out a way to semi-automatically manage a set of IFB devices for a number of network interfaces. Currently I have no problem finding out if a given “real” interfaces is connected to an IFB:

root@nacktmulle:~# tc -s filter show parent ffff: dev ge00
filter protocol all pref 10 u32 
filter protocol all pref 10 u32 fh 800: ht divisor 1 
filter protocol all pref 10 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 
  match 00000000/00000000 at 0
	action order 1: mirred (Egress Redirect to device ifb1) stolen
 	index 47 ref 1 bind 1 installed 521 sec used 3 sec


I am looking for a way of doing the reverse,i.e.  figuring out for a given IFB if it is “connected” to a real interface and, if yes, which interface. Basically, I want to recycle unused IFBs, but want to make sure that they really are unused…

Thanks in advance
	Sebastian Moeller

Re: how to figure out which device a given IFB is connected to

[Cong Wang]

On Mon, Sep 15, 2014 at 7:37 AM, Sebastian Moeller <moeller0@gmx.de> wrote:
> I am looking for a way of doing the reverse,i.e.  figuring out for a given IFB if it is “connected” to a real interface and, if yes, which interface. Basically, I want to recycle unused IFBs, but want to make sure that they really are unused…
>

There is no way to figure that out.

Re: how to figure out which device a given IFB is connected to

[Sebastian Moeller]

Hi Mr. Wang,

Thank you for your help.

On Sep 15, 2014, at 18:08 , Cong Wang <cwang@twopensource.com> wrote:

> On Mon, Sep 15, 2014 at 7:37 AM, Sebastian Moeller <moeller0@gmx.de> wrote:
>> I am looking for a way of doing the reverse,i.e.  figuring out for a given IFB if it is “connected” to a real interface and, if yes, which interface. Basically, I want to recycle unused IFBs, but want to make sure that they really are unused…
>> 
> 
> There is no way to figure that out.

	That is rather unfortunate, so my only recourse is to get a list of all interfaces and query each whether it is attached to an fib and prune a list of IFBs so that only the unused ones remain (which is far from elegant ;) ).

Best Regards
	Sebastian Moeller

Re: how to figure out which device a given IFB is connected to

[Stephen Hemminger]

On Mon, 15 Sep 2014 21:06:31 +0200
Sebastian Moeller <moeller0@gmx.de> wrote:

> Hi Mr. Wang,
> 
> Thank you for your help.
> 
> On Sep 15, 2014, at 18:08 , Cong Wang <cwang@twopensource.com> wrote:
> 
> > On Mon, Sep 15, 2014 at 7:37 AM, Sebastian Moeller <moeller0@gmx.de> wrote:
> >> I am looking for a way of doing the reverse,i.e.  figuring out for a given IFB if it is “connected” to a real interface and, if yes, which interface. Basically, I want to recycle unused IFBs, but want to make sure that they really are unused…
> >> 
> > 
> > There is no way to figure that out.
> 
> 	That is rather unfortunate, so my only recourse is to get a list of all interfaces and query each whether it is attached to an fib and prune a list of IFBs so that only the unused ones remain (which is far from elegant ;) ).

It can be a many to one mapping.
There are cases where you want multiple incoming devices to all be QoS'd together.

Re: how to figure out which device a given IFB is connected to

[Sebastian Moeller]

Hello Mr. Hemminger,


On Sep 15, 2014, at 22:55 , Stephen Hemminger <stephen@networkplumber.org> wrote:

> On Mon, 15 Sep 2014 21:06:31 +0200
> Sebastian Moeller <moeller0@gmx.de> wrote:
> 
>> Hi Mr. Wang,
>> 
>> Thank you for your help.
>> 
>> On Sep 15, 2014, at 18:08 , Cong Wang <cwang@twopensource.com> wrote:
>> 
>>> On Mon, Sep 15, 2014 at 7:37 AM, Sebastian Moeller <moeller0@gmx.de> wrote:
>>>> I am looking for a way of doing the reverse,i.e.  figuring out for a given IFB if it is “connected” to a real interface and, if yes, which interface. Basically, I want to recycle unused IFBs, but want to make sure that they really are unused…
>>>> 
>>> 
>>> There is no way to figure that out.
>> 
>> 	That is rather unfortunate, so my only recourse is to get a list of all interfaces and query each whether it is attached to an fib and prune a list of IFBs so that only the unused ones remain (which is far from elegant ;) ).
> 
> It can be a many to one mapping.
> There are cases where you want multiple incoming devices to all be QoS'd together.

	Good to know, thanks for this information.

Best Regards
	Sebastian Moeller