[OpenIndiana-discuss] OI Hipster becomes unreachable over network after a certain length of uptime

[Udo Grabowski (IMK)]

On 12/04/2022 20:42, Bob Friesenhahn wrote:
> On Tue, 12 Apr 2022, Judah Richardson wrote:
> 
>> On Tue, Apr 12, 2022, 13:27 Udo Grabowski (IMK) <udo.grabowski at kit.edu>
>> wrote:
>>
>>> On 12/04/2022 20:00, John D Groenveld wrote:
>>>> In message <e042f009-5caa-bae0-5181-d294d4ad213b at kit.edu>, "Udo
>>> Grabowski (IMK)
>>>> " writes:
>>>>> No, it isn't, it's controlled by
>>>>> /lib/svc/manifest/network/routing/route.xml ,
>>>>> which is not enabled by default, as practically no machine
>>>>> in the field is working as a router, you have to specifically
>>>>> enable the route:default service.
>>>>
>>>> svc:/network/routing/route is enabled out of the box with
>>>> OI-hipster-text-20211031.iso
>>>
>>> Why ?? This hasn't been the case for at least two decades of
>>> Solaris and beyond.
>>
>> Probably an oversight, I'd guess. As with many such situations, things 
>> that
>> aren't obviously and critically broken don't get much attention ;)
> 
> It is not really an oversight since all computers with a TCP/IP stack 
> need to deal with some level of routing even if they are not acting as a 
> gateway.  If there is ever more than one way to get "there" via the L2 
> network then running a higher-level routing protocol (e.g. RIP) can help 
> the TCP/IP stack make the right decisions if the involved routers use 
> the same protocol.  The host might participate in RIP or it might just 
> act as an observer.
> 
> In many cases one or more computers are attached to a shared L2 network 
> with a single upstream router. In this case, using DHCP to configure the 
> default route, or static configuration to provide the default route, can 
> be a good choice. There are other means such as ICMP Router Discovery 
> Protocol (https://en.wikipedia.org/wiki/ICMP_Router_Discovery_Protocol) 
> or even ICMP redirects.

I have a few machines with two L2 networks (a.k.a. tagged VPN), and even
those don't require the routing service. In fact, in my over 3 decades
of experience with Sun machines, I only once have seen that the routing
service had to be active. That one case was when I experimented with the
COMSTAR network simulation tools to play with virtual switches and
routers.