IP routing problems on GCP

IP routing problems on GCP

[Kyohei Kadota]

Hi.

I'm migrating my 9legacy machines to GCP but my auth/cpu servers can't
get root from the fileserver.
Is there someone that is using full system Plan 9 on GCP?

Notes:
- DHCP of VPC network on GCP sends ipmask=/32 options to that client.
- If ipmask is /32 then ip/ipconfig ignores it.
- Therefore each instance can't reach other instances in the same region.

In my experience, the communications works only if /net/ipifc is
configured from /lib/ndb/local by ip/ipconfig -N, its ipmask is /20,
and it is added to /net/iproute manually that the routes to other
instances, but in this case, the cpu/auth servers couldn't reach to
the fs because nothing to add the routes before getting root.

--
kadota

Re: [9fans] IP routing problems on GCP

[David du Colombier]

> I'm migrating my 9legacy machines to GCP but my auth/cpu servers can't
> get root from the fileserver.
> Is there someone that is using full system Plan 9 on GCP?

Yes, but only using a local file server. 
I've never tried to boot Plan 9 from a remote file server so far.

> Notes:
> - DHCP of VPC network on GCP sends ipmask=/32 options to that client.
> - If ipmask is /32 then ip/ipconfig ignores it.
> - Therefore each instance can't reach other instances in the same region.
> 
> In my experience, the communications works only if /net/ipifc is
> configured from /lib/ndb/local by ip/ipconfig -N, its ipmask is /20,
> and it is added to /net/iproute manually that the routes to other
> instances, but in this case, the cpu/auth servers couldn't reach to
> the fs because nothing to add the routes before getting root.

9legacy includes a patch that considers 32 mask as 0.

http://9legacy.org/9legacy/patch/ip-ipconfig-mask.diff

-- 
David du Colombier

Re: [9fans] IP routing problems on GCP

[Kyohei Kadota]

> ip-ipconfig-mask.diff

What intentions were these changes added?

Though I'm not sure why that was added, I've noticed that DHCP of the
VPC sends two Classless Static Route options. (DHCP option number:
121)

1. ip=0.0.0.0   mask=/0  remote=17.xx.0.1
2. ip=17.xx.0.1 mask=/32 remote=0.0.0.0

In my opinion, maybe remote=0.0.0.0 means the ipnet will be attached
directly to the interface.
If it is true, currently, my instance on GCP has been able to get the
correct network configuration
from DHCP with *hacked* kernel and ip/ipconfig.

2020年8月24日(月) 2:41 David du Colombier <0intro@gmail.com>:
>
> > I'm migrating my 9legacy machines to GCP but my auth/cpu servers can't
> > get root from the fileserver.
> > Is there someone that is using full system Plan 9 on GCP?
>
> Yes, but only using a local file server.
> I've never tried to boot Plan 9 from a remote file server so far.
>
> > Notes:
> > - DHCP of VPC network on GCP sends ipmask=/32 options to that client.
> > - If ipmask is /32 then ip/ipconfig ignores it.
> > - Therefore each instance can't reach other instances in the same region.
> >
> > In my experience, the communications works only if /net/ipifc is
> > configured from /lib/ndb/local by ip/ipconfig -N, its ipmask is /20,
> > and it is added to /net/iproute manually that the routes to other
> > instances, but in this case, the cpu/auth servers couldn't reach to
> > the fs because nothing to add the routes before getting root.
>
> 9legacy includes a patch that considers 32 mask as 0.
>
> http://9legacy.org/9legacy/patch/ip-ipconfig-mask.diff
>
> --
> David du Colombier
>
> ------------------------------------------
> 9fans: 9fans
> Permalink: https://9fans.topicbox.com/groups/9fans/Tc21c3dd261e604cf-M926904f4ad643a6a16f23051
> Delivery options: https://9fans.topicbox.com/groups/9fans/subscription