[Babel-users] filtering harder?

[Dave Taht]

On Wed, Nov 19, 2014 at 2:40 PM, Dave Taht <dave.taht at gmail.com> wrote:
> On Wed, Nov 19, 2014 at 2:19 PM, Juliusz Chroboczek
> <jch at pps.univ-paris-diderot.fr> wrote:
>>> So given that I was exporting a x.y.128.0/20
>>> I had wondered how to filter out the 128.1, 130.1, 129.1
>>> on the 3 interfaces from the rangeley.
>>
>> I'm still not clear about what you're doing, but if it's a simple matter
>> of not redistributing these routes, you can simply say:
>>
>>   redistribute local ip x.y.128.1/32 deny
>
> Thank you, that did the trick. I was kind of looking for a
> generic syntax for matching all 3. (0.0.0.0/32 eq 32?).
> (the situation is that I would like babel to monitoring IFF_RUNNING
>  but dont need the .1s as I have the covering route)
>
> Looking 5 hops further into my network and waiting for a while
> showed this:
>
> root at lounge:~# ip route | grep 172.21
>
> 172.21.2.21 via 172.20.2.4 dev se00  proto babel onlink
> 172.21.128.0/20 via 172.20.2.4 dev se00  proto babel onlink
> unreachable 172.21.128.1  proto babel  metric 4294967295 onlink
> 172.21.128.10 via 172.20.2.4 dev se00  proto babel onlink
> unreachable 172.21.130.1  proto babel  metric 4294967295 onlink
>
> Which then cleared a few seconds later
>
> 172.21.2.0/24 via 172.20.2.4 dev se00  proto babel onlink
> 172.21.2.21 via 172.20.2.4 dev se00  proto babel onlink
> 172.21.128.0/20 via 172.20.2.4 dev se00  proto babel onlink
> 172.21.128.10 via 172.20.2.4 dev se00  proto babel onlink
>
> 1) Am I saving any on packet size by doing this much filtering?
>
> 2) (note that this is a very simplified example, I presently have 48
> (used to 90) routes for ipv4 and am about to add 5 source specific
> ipv6 gateways and that related potential explosion of routes
> scares me)
>
> 3) As for the last, 10 entry, this is basically a stubby box,
> (network monitor) and  guess I could also tell it to not redistribute
> its ip the same way, but either need to hook it into dhcp to get its
> address, or
> redistribute local ip deny?

To sort of explain what I am up to - I have a a bunch of beaglebone
blacks that I use to run tools like smokeping and mrtg and periodic
bufferbloat related tests. I would like to get to the point where I
can just drop one in the network, anywhere, and have it get an
address(s) from hnetd, and get its default(s) routing from babel,
register in dns, and then start doing stuff - without the need for me
to be logged
in at that particular point.

(not, incidentally, that I have hnetd working on debian, or have
smokeping capable of selecting various different local ipv6
prefixes. yet. And I guess I should patch in mptcp, also... and
if anyone has more suggestions as to how to test hncpd and source
specific routing at scale, let me know...)

Actually I would like it to get to where it flashed a green light upon
achieving that level of connectivity...

>>
>> If you want to avoid redistributing them over just some interfaces, you
>> need to hook your filter at a different place:
>>
>>   out ip x.y.128.1 if wlan42 deny
>
> heh. Well, ages ago I had got this working right with nat in the way
> for ipv4 but allowing ipv6.
>
> Thankfully now the network is thoroughly de-natted and uniquely numbered.
>
>>
>> -- Juliusz
>>
>
>
>
> --
> Dave Täht
>
> thttp://www.bufferbloat.net/projects/bloat/wiki/Upcoming_Talks



-- 
Dave Täht

thttp://www.bufferbloat.net/projects/bloat/wiki/Upcoming_Talks