Router upgrade....

[Matthew D. Fuller]

On Wed, Apr 26, 2006 at 02:45:30PM +0100 I heard the voice of
Brian Candler, and lo! it spake thus:
> 
> I think you're forgetting the time sat in single-user mode while
> doing installworld and manually mergemaster'ing the rc scripts.

No, I'm not, because I wouldn't do that   :)

When I upgraded some production systems from RELENG_2_2 to mid-life
RELENG_4, you're darn tootin' I did a lot of work in single-user mode
(and some off boot disks, for that matter).  But extraordinary
circumstances aside, I do virtually all my upgrades in normal
multi-user, and often many miles from the console.

Now, I get away with it because I've done a lot of upgrades before,
and I watch the mailing lists and keep track of any gotchas in a given
upgrade.  But Usually(tm) there's not even a twitch.  I've done
upgrades from 5.3/5.4ish to RELENG_6 remotely (no console, just ssh)
several times, on i386 and amd64, and wouldn't flinch at doing it
again.

To a large extent, the smoothness of doing so is related to how often
you do it; if you go a year or two between upgrades, accumulated
differences can make things really unpleasant, while doing it every
few months is usually grass through a duck.


> Personally I prefer the other option suggested by the OP:
> - build a brand new router using whatever O/S and software revisions you
>   choose to be on

Which is the other extreme.  I've rarely been in a situation where I
consider my "normal" method too risky and went with something like
this, but "rarely" isn't "never".

In the end, you always have to balance.  In the OP's case, I wouldn't
be too worried about just doing it in-place; whether that would apply
for anyone else, I (obviously) couldn't say.


> If you want it to come up on the same IP address then you may have
> to clear ARP caches on some other devices on the same LAN
> segment(s), but that's about it.

If you got real smart, you could just pull the NIC and put it in the
new box, so even if something was foolishly holding onto the MAC, it
would still get there   :)


-- 
Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
           On the Internet, nobody can hear you scream.