Re: TTL as a factor in route flaps

[Frederico A C Neves <fneves@registro.br>]

On Fri, Oct 13, 2000 at 04:29:07PM +0200, Simon Leinen wrote:
> >>>>> "sg" == Steve Glines <sglines@is-cs.com> writes:
> > I noticed that aroot.psg.com has a 4 hour TTL. This is about how long I
> > recorded continuous failures while the net switched from the server in
> > Brazil to the one in Switzerland. Any thoughts on this? 
> 
> The TTL shouldn't have any influence on the routes you see from
> traceroute, because the A record for aroot.psg.com always points to
> the same address (192.83.230.1).
> 
> Why rerouting should take four hours strikes me as mysterious.  Maybe
> the server in Brazil was down for some reason, but the route was still
> being advertized from there?

bash> uname -a
FreeBSD sroot.DNS.BR 4.1-STABLE FreeBSD 4.1-STABLE #4: Sat Sep  2 13:17:45 EST 2000     root@fe.registro.br:/usr/src/sys/compile/BARBERA  i386
bash> uptime
12:33PM  up 40 days, 21:53, 1 user, load averages: 0.00, 0.00, 0.00
bash> 

sroot> sh ip bgp sum
 Neighbor        V     AS MsgRcvd MsgSent   TblVer InQ OutQ Up/Down  State/Pref
143.108.13.65    4   1251   58863   58882       0    0    0 1d20h44m         0
sroot> sh ip bgp neighbors 143.108.13.65 advertised-route 
*> 192.83.230.0/24     143.108.13.78                            32768 i

We have had a problems in the core router 2 days ago but now we are
ok. We are congested on the downstream but we have plenty of bandwidth
from here to C&W. Until the new OC3 get up and running on the next 2
months this will be our best shot.

> -- 
> Simon Leinen				       simon@babar.switch.ch
> SWITCH				   http://www.switch.ch/misc/leinen/
> 
> 	    Who is General Failure & why's he reading my disk?
> 

-- 
 Frederico A C Neves              Registro .br - R.Pio XI, 1500
 +55 11 3838-4130             São Paulo, SP, Brazil - 05468-901