[j-nsp] aggregates - active/passive option

Discussion:

Jeroen Valcke

2005-02-02 10:10:27 UTC

Hello,

I was experimenting a bit with aggregate routes and noticed something
which seems weird to me.

I have configured a series of aggregate routes with the JunOS default
parameters (by default the active parameter is set). The aggregate
routes don't get installed in the routing table, since I don't have any
contributing routes. So that's quite normal.

Then when I change the active/passive parameter to passive for all these
aggregate routes, they do get installed in the routing table. I find
this to be weird since the doc says;

passive - Have a route remain continually installed in the
routing and forwarding tables even when it becomes inactive.

Reading this, one would expect that the route should at least have been
active before. Then how come it installs the aggregate route although
the route itself has never been active?

Best regards,
-Jeroen-

Configuring Aggregate Routes
http://www.juniper.net/techpubs/software/junos/junos70/swconfig70-routing/html/routing-tables-config24.html

Active/Passive Parameter for Aggregate Routes
http://www.juniper.net/techpubs/software/junos/junos70/swconfig70-routing/html/routing-summary2.html#1013936

--
Jeroen Valcke

Stefan Fouant

2005-02-02 16:04:47 UTC

Permalink

I believe the passive option when used with aggregate / generated routes
will cause the route to be continually installed in the routing and
forwarding tables, even in light of no contributing routes. However, if
there are no contributing routes, the next-hop will be set to reject.

Stefan Fouant
Senior Network Engineer
UUNET / MCI

Post by Jeroen Valcke
Hello,
Then when I change the active/passive parameter to passive for all these
aggregate routes, they do get installed in the routing table. I find
this to be weird since the doc says;
passive - Have a route remain continually installed in the
routing and forwarding tables even when it becomes inactive.
Reading this, one would expect that the route should at least have been
active before. Then how come it installs the aggregate route although
the route itself has never been active?
Best regards,
-Jeroen-

Bostjan Fele

2005-02-03 13:30:45 UTC

Permalink

Hi,

aggregate routes have only two next-hop options: reject (default) or
discard. First one enables ICMP messages if there is no more specific route,
second one silently discards packet. This has nothing to do with having a
contributing route. I have not checked if passive option installes aggregate
route in first place if there is no contributing route or not. I would try
this with configuring one static route to contribute and then remove it.

REgards,
Bostjan Fele

-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net]On Behalf Of Stefan Fouant
Sent: Wednesday, February 02, 2005 4:05 PM
To: Jeroen Valcke
Cc: juniper-nsp at puck.nether.net
Subject: Re: [j-nsp] aggregates - active/passive option

I believe the passive option when used with aggregate / generated routes
will cause the route to be continually installed in the routing and
forwarding tables, even in light of no contributing routes. However, if
there are no contributing routes, the next-hop will be set to reject.

Stefan Fouant
Senior Network Engineer
UUNET / MCI

_______________________________________________
juniper-nsp mailing list juniper-nsp at puck.nether.net
http://puck.nether.net/mailman/listinfo/juniper-nsp

C. Hagel

2005-02-04 17:07:11 UTC

Permalink

All,
The "passive" option WILL install the aggregate route when there
are no active contributing routes (as will a "generate route"). When
you create a aggregate route without the "passive" switch and there are
no contributing routes, the aggregate route will not be active and will
not be passed on.
For next-hop options there actually are 3, #1 is nothing behind
the route (i.e. aggregate route x.x.x.x <cr>) this will give you the
next-hop of the contributing routes. #2 reject (i.e. aggregate route
x.x.x.x reject) this will send an ICMP message for any packet that is
destine to your aggregate address (i.e. root at router> ping 10.200.1.0 where
10.200.1.0/24 is your aggregate route). #3 discard (i.e. aggregate route
x.x.x.x discard) this will silently discard any route that is destine to the
aggregae route (i.e. root at router> ping 10.200.1.0 where 10.200.1.0/24
is your aggregate route).

On Thu, 3 Feb 2005 13:30:45 +0100
Bostjan Fele <bostjan.fele at smart-com.si> wrote:

BF> Hi,
BF>
BF> aggregate routes have only two next-hop options: reject (default) or
BF> discard. First one enables ICMP messages if there is no more specific route,
BF> second one silently discards packet. This has nothing to do with having a
BF> contributing route. I have not checked if passive option installes aggregate
BF> route in first place if there is no contributing route or not. I would try
BF> this with configuring one static route to contribute and then remove it.
BF>
BF> REgards,
BF> Bostjan Fele
BF>
BF> -----Original Message-----
BF> From: juniper-nsp-bounces at puck.nether.net
BF> [mailto:juniper-nsp-bounces at puck.nether.net]On Behalf Of Stefan Fouant
BF> Sent: Wednesday, February 02, 2005 4:05 PM
BF> To: Jeroen Valcke
BF> Cc: juniper-nsp at puck.nether.net
BF> Subject: Re: [j-nsp] aggregates - active/passive option
BF>
BF>
BF> I believe the passive option when used with aggregate / generated routes
BF> will cause the route to be continually installed in the routing and
BF> forwarding tables, even in light of no contributing routes. However, if
BF> there are no contributing routes, the next-hop will be set to reject.
BF>
BF> Stefan Fouant
BF> Senior Network Engineer
BF> UUNET / MCI
BF>
BF> Jeroen Valcke wrote:
BF> > Hello,
BF> >
BF> > Then when I change the active/passive parameter to passive for all these
BF> > aggregate routes, they do get installed in the routing table. I find
BF> > this to be weird since the doc says;
BF> >
BF> > passive - Have a route remain continually installed in the
BF> > routing and forwarding tables even when it becomes inactive.
BF> >
BF> > Reading this, one would expect that the route should at least have been
BF> > active before. Then how come it installs the aggregate route although
BF> > the route itself has never been active?
BF> >
BF> > Best regards,
BF> > -Jeroen-
BF> _______________________________________________
BF> juniper-nsp mailing list juniper-nsp at puck.nether.net
BF> http://puck.nether.net/mailman/listinfo/juniper-nsp
BF>
BF> _______________________________________________
BF> juniper-nsp mailing list juniper-nsp at puck.nether.net
BF> http://puck.nether.net/mailman/listinfo/juniper-nsp

--
Chris Hagel
JNCIP #103
<nanog at lordkron.net>

Joseph Soricelli

2005-02-04 18:09:25 UTC

Permalink

Actually, aggregate routes only have 2 next hop options - reject and
discard. Reject is the default next hop and is what you get with aggregate
route x.x.x.x <cr>. To get an IP next-hop assigned to an aggregate route
(from a contributor), you need to configure a generate route.

-joe

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joe Soricelli
Director of Education Services
iPath Technologies
www.ipath.net
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Post by Bostjan Fele
-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net [mailto:juniper-nsp-
bounces at puck.nether.net] On Behalf Of C. Hagel
Sent: Friday, February 04, 2005 10:54 AM
To: Bostjan Fele
Cc: juniper-nsp at puck.nether.net
Subject: Re[2]: [j-nsp] aggregates - active/passive option
All,
The "passive" option WILL install the aggregate route when there
are no active contributing routes (as will a "generate route"). When
you create a aggregate route without the "passive" switch and there are
no contributing routes, the aggregate route will not be active and will
not be passed on.
For next-hop options there actually are 3, #1 is nothing behind
the route (i.e. aggregate route x.x.x.x <cr>) this will give you the
next-hop of the contributing routes. #2 reject (i.e. aggregate route
x.x.x.x reject) this will send an ICMP message for any packet that is
destine to your aggregate address (i.e. root at router> ping 10.200.1.0
where
10.200.1.0/24 is your aggregate route). #3 discard (i.e. aggregate route
x.x.x.x discard) this will silently discard any route that is destine to
the
aggregae route (i.e. root at router> ping 10.200.1.0 where 10.200.1.0/24
is your aggregate route).
On Thu, 3 Feb 2005 13:30:45 +0100
BF> Hi,
BF>
BF> aggregate routes have only two next-hop options: reject (default) or
BF> discard. First one enables ICMP messages if there is no more specific
route,
BF> second one silently discards packet. This has nothing to do with
having a
BF> contributing route. I have not checked if passive option installes
aggregate
BF> route in first place if there is no contributing route or not. I would
try
BF> this with configuring one static route to contribute and then remove
it.
BF>
BF> REgards,
BF> Bostjan Fele
BF>
BF> -----Original Message-----
BF> From: juniper-nsp-bounces at puck.nether.net
BF> [mailto:juniper-nsp-bounces at puck.nether.net]On Behalf Of Stefan Fouant
BF> Sent: Wednesday, February 02, 2005 4:05 PM
BF> To: Jeroen Valcke
BF> Cc: juniper-nsp at puck.nether.net
BF> Subject: Re: [j-nsp] aggregates - active/passive option
BF>
BF>
BF> I believe the passive option when used with aggregate / generated
routes
BF> will cause the route to be continually installed in the routing and
BF> forwarding tables, even in light of no contributing routes. However,
if
BF> there are no contributing routes, the next-hop will be set to reject.
BF>
BF> Stefan Fouant
BF> Senior Network Engineer
BF> UUNET / MCI
BF>
BF> > Hello,
BF> >
BF> > Then when I change the active/passive parameter to passive for all
these
BF> > aggregate routes, they do get installed in the routing table. I find
BF> > this to be weird since the doc says;
BF> >
BF> > passive - Have a route remain continually installed in the
BF> > routing and forwarding tables even when it becomes inactive.
BF> >
BF> > Reading this, one would expect that the route should at least have
been
BF> > active before. Then how come it installs the aggregate route
although
BF> > the route itself has never been active?
BF> >
BF> > Best regards,
BF> > -Jeroen-
BF> _______________________________________________
BF> juniper-nsp mailing list juniper-nsp at puck.nether.net
BF> http://puck.nether.net/mailman/listinfo/juniper-nsp
BF>
BF> _______________________________________________
BF> juniper-nsp mailing list juniper-nsp at puck.nether.net
BF> http://puck.nether.net/mailman/listinfo/juniper-nsp
--
Chris Hagel
JNCIP #103
<nanog at lordkron.net>
_______________________________________________
juniper-nsp mailing list juniper-nsp at puck.nether.net
http://puck.nether.net/mailman/listinfo/juniper-nsp

Bostjan Fele

2005-02-07 04:57:22 UTC

Permalink

Actually we are talking about two routes (as configured under
routing-options): aggregate and generated. Generated get next hop from
primary contributor, aggregate has only reject/discard next-hop. In policy
statements they have both same name, protocol aggregate. Maybe this was
misunderstanding.... ;-)

Regards,
Bostjan

-----Original Message-----
From: Joseph Soricelli [mailto:joe at ipath.net]
Sent: Friday, February 04, 2005 6:09 PM
To: 'C. Hagel'; 'Bostjan Fele'
Cc: juniper-nsp at puck.nether.net
Subject: RE: Re[2]: [j-nsp] aggregates - active/passive option

Actually, aggregate routes only have 2 next hop options - reject and
discard. Reject is the default next hop and is what you get with aggregate
route x.x.x.x <cr>. To get an IP next-hop assigned to an aggregate route
(from a contributor), you need to configure a generate route.

-joe

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joe Soricelli
Director of Education Services
iPath Technologies
www.ipath.net
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~